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FAQs About Water Evaporation, Make-Up H20 1

Related Articles: Marine Water Change, Captive Seawater Quality, General  Marine Maintenance

Related FAQs: Make-up Water 2, Water Changes for Marine Systems 1, Make-up Water: Rationale/Use, Gear, Frequency/Amount, Techniques, Water Quality/Adjusting, Trouble/shooting, & Top-Off System s, Controllers, Treating Tapwater Marine Water QualityMarine Plumbing

Phataria unifascialis (Gray 1840), the Blue Sea Star.

Helpful Roommate. Adding bottled water to top off a system 12/14/2009
Hi guys. Long time follower of your site.
<Hi Greg.>
Yesterday my friendly roommate noticed that the water level in my refugium was a little low. We have been chatting lately about my 75 gallon with a 30 gallon refugium marine tank.
I guess he was feeling helpful and "in the loop", so he decided to add a gallon of Harris Teeter drinking water to the tank.
<Well, if you were a gallon down, that should be fine.>
I wanted to kill him.
<Nothing that drastic is necessary.>
On the label of the drinking water it says, "Prepared by carbon filtration, microfiltration, and ozonization for purity. How worried should I be?
<As long as it was not chlorinated or carbonated, it should be fine.>
I have a bunch of sps and xmas tree worm rock that has thrived for over 3 years. My LFS is closed until Tuesday which is where I usually purchase salt water. Should I just wait and then do a water change on Tuesday, or will the aquarium to a relative, murder my roommate, and suffer the consequences?
<No worries. remember, you need to top off evaporated water with fresh water. Double check your salinity and water parameters, but I highly doubt any harm was done.>

Make-Up Water 11/17/09
I made up 10 gallons of makeup water on Sunday for a water change I was planning on doing later on in the week. There was still maybe a gallon left in my tote from the last water change. I tested the salt level on Monday and also decided to check for ammonia and I actually found some.
Its somewhere on the color card between .25 and .5.
<I'm assuming the ammonia level was found in the gallon of water you had left. If so, I would test the R/O water for ammonia before adding the salt, just a process of elimination. Was Windex or similar products used in the area of the make-up water?>
I am using R/O water from the Culligan man and reef crystals. Is this water safe to use for a water change?
<Should be, but if in doubt, test before mixing the salt. James (Salty Dog)>

Re Make-Up Water 11/17/09
I found the ammonia after I added that 10 gallons of r/o and salt to it and let it sit for a day. No chemicals are used in the area I have my totes.
<I would check the make-up water before mixing the salt. I'm leaning toward an erroneous reading of the test kit. Have you compared the reading with one taken of your display tank water?>
I noticed that I have salt gathering and sticking to my heater I have in the tote is this a problem?
<No, is likely calcium build up, easily cleaned by soaking overnight in a vinegar solution. James (Salty Dog)>

RO/DI Top Off Water 11/4/09
Hello Guys!
<Hi Roger>
Now running a 125 gal FOWLR/LS. I'm using a 90 GPD Spectrapure RO/DI unit for my "top off" and saltwater changes.
Read a lot about preparation prior to adding salt but what do I need to do with this low pH/Alk water for daily top offs?
I've taken notes, please tell me if this is correct !!!
1 - aerate for 12-24 hrs.
<Not necessary with RO/DI water.>
2 - Add sea buffer, is there a difference between Aquarium Systems vs. CaribSea?
<I do not readily know the make up of these two, but my choice would be Seachem and/or Tropic Marin products.>
Add appropriate amount to buffer to 8.0?
<I would shoot for something closer to 8.2..>
Aerate for an additional 24 hrs.
<Using a powerhead to mix the buffer will be fine.>
This freshwater can now be used for my "top off" needs?
<Yes, and I would keep the RO/DI water temperature close to what your system temperature is.>
3 - Later, add salt for regular water changes.
<Yes. You may want to read articles/FAQ's here.
Thank you so very much.
<You're welcome. James (Salty Dog)>
RJS - Retired Salmon Biologist

Maintaining dKH using buffers in ATO: Chasing numbers. SW Alk\pH\Ca balancing 8/6/2009
Hello Crew,
<Hi Mark.>
I'm jumping over here from the WWM Forum to maybe get an answer to my question and a potential solution. You have been tremendously helpful in the past and I appreciate the service you provide. I've read through much of the discussions on PH, alkalinity, and calcium at WWM and I believe I have a fairly good understanding of it.
<So you understand that as Ca rises, Alk will fall, and as a general rule of thumb, Mg should be 3x the Ca levels.>
However, after implementing what I thought would be a relatively easy way to keep my system alkalinity stable, I find myself with a small problem that I can't seem to figure out. I'm having a problem keeping my dKH stable without adding buffers to the tank. I want to be able to keep it buffered with the ATO water.
I measure my dKH regularly and I'm having trouble maintaining anything above 8 and it occasionally falls to 7 dKH.
<Which is fine actually.>
I can, with additives, get the dKH higher than 8, but it seems to want to fall back to 8 or less
even with massive amounts of buffer in the ATO water.
<So why keep fighting it?>
What is confusing to me is that I took readings this morning and my tank was at 7dKH. I
checked my premixed salt water and it's at 8dKH.
<No biological activity in the premix to bring it down.>
I checked my FW ATO tub and it's at 21dKH.
<Wow, How much are you buffering?.>
I use Sea Chem powdered products (Reef Buffer & Reef Builder) in my ATO water to buffer the tank, but I never really know how much to add or how high I need the dKH to be to keep the tank alkalinity up.
<A dKH of 6 - 12 is fine, provided it is stable.. Remember, stability is more important that a set number.>
I perform weekly 10 gallon water changes. I recently changed from Reef Crystals to SeaChem Reef Salt and that seems to be helping a small Cyano battle I've been wagering for the last year. I just couldn't completely knock the stuff out, so I changed salts to see if it helped.
It seems to be helping. The Cyano is retreating again, not that there was massive amounts of it....but it's ugly. The LR rock looks noticeable better too after only 4 weeks.
<A good sign. You don't mention what else is in the tank though..>
What I do not understand is how the dKH can be so high in the ATO water and it seems to be doing nothing to keep the tank dKH level from dropping.
<The buffers are being used\ 'burned' up or precipitating out of solution.>
My ATO uses about 1.5 gallons per day. This has been an ongoing issue since I set the system up. I'd be happy to keep the dKH stable at 8 or 9, but I don't seem to be able to do that without adding buffer directly to the tank occasionally. All of my RO/DI water is aerated for several days before use.
The only thought I've had is that I need to start buffering my premixed salt water to a higher dKH as well as the ATO water.
<A dKH of 8 is fine for premixed water.>
Readings taken last night:
PH: between 8.0 and 8.5 (hard to read between the scale)
<How much does it swing between lights on and lights off?>
dKH: 8 (added reef Builder in the morning, was dKH 7)
<If you don't add anything, what does it drop to?>
Calcium: 375 (time to add some Reef Complete)
<What is your calcium demand over a period of time?>
Magnesium: 1410
Phosphate: undetectable
Nitrate: 0
Tank: setup in April of 2008
90 gallon reef tank
30 gal DIY sump with integral refugium..7-8 gallon (Aragonite DSB and macro Algae)
1.5" drain
MAG 7 return pump
1/2" of sugar fine Aragonite substrate
<All fine. Do you use reverse lighting on your refugium?>
Aqua C EV-120 running on a MAG 5
50-60lbs of Live Rock
MAG 18 on Closed Loop for added circulation
(2) 150W 10K HQI's
(2) 55W Actinic
(1) 55W 10K Power Compact over refugium for macro growth
Support Eq:
Typhoon III 150 gallon per day RO/DI unit
15 gallon container with Buffered RO/DI water and Tunze ATO unit
29 Gallon tank for premixed salt water
<All good.>
<I think you are caught in a trap many of us get wrapped up in: Chasing numbers. The 'book' or specification states that dKH should be X and Ca should be Y so we add buffers and chemicals, and dose this and that and wind up chasing our tails.>
<What you need to do here is stop. Other than salt, and enough buffer in your top off water to get a pH of 8.2 - 8.4 and a dKH of about 7 - 8, stop adding chemicals to your system. Then, measure your dKH, pH and Ca both morning and night for a few days. record your readings. If your dKH drops below 6, add just enough buffer to bring it back. You should know what your calcium demand is, ad well as what your dKH wants to naturally rest at.. The key thing to realize is, if your Alk wants to stay at 7, let it.
Stability is much more important than chasing that perfect number.>
Thanks Again
<My pleasure, will also be posting this on the forum.>

ATO Question: Siphoning 7/20/2009
Dear Crew,
<Hi Andy.>
Happy Friday. Many of you have helped me work through the crash of my tank last September. By pure luck and good fortune, I finally figured out how it happened.
<Good news.>
I have a Tunze auto top-off system. The outlet hose for the ATO is clipped to the top of my sump--I'd say 12" high off the bottom of the stand. I recently vacationed in Alaska and went through my normal protocol. I filled a Brute trash can with 30 gallons or so of RO/DI water for top off, and threw my Tunze pump in there. As luck would have it, I did one last check of my system before I headed to the airport and I noticed that even though my Tunze ATO pump was not cycled on, there was a slow trickle of water from the ATO hose outlet.
<Uh oh.>
So, it appears that a siphon is created once the ATO pump starts, which isn't broken when it cycles off.
<Likely so.>
This explains why my floor was wet when my tank crashed--the sump overflowed, water made contact with
either my return pump or my HQI ballasts, which tripped the circuit breaker.
How can this happen if the pump sits below the hose outlet? I'm thinking that it's because the trash can is so high, that the height of the hose coming over the top of the trash can overcomes the 12" or so height difference between the position of the outlet hose and the floor where the pump sits??
<That is it exactly.>
I am heading to the beach for a week at the end of August, so I need to sort this out. I was considering buying a large shallow tub that is no higher than the height of the outlet hose.
<That would be better. Remember the water hose will fill up to the level of the water in its container, so a shallower container is less likely to siphon.>
Thanks for your help.
<My pleasure.>

Re: ATO Question: Siphoning 7/21/2009
Thanks, Mike.
<Hi Andy.>
I thought this was impossible--that you couldn't have a siphon if the outlet is higher than the inlet.
<Not true - particularly if there is a large mass of water over the inlet to provide pressure. It won't be as efficient, but it will still siphon.>

Top off water and Testing for RO Water TDS 4/27/09
Bob and the Gang,
<Hello Joe>
Hope all is well.
My 135 G Reef tank loses a lot of water due to evaporation.
I add a fair amount of RO water to top it off weekly.
<Am I to understand you top off the tank once a week? Or do you mean you lose a lot of water over the course of a week. If you are topping off only once a week I suggest you try to do it more often, the longer you wait before topping off the tank, the larger the swings in the specific gravity of the water your tank will experience>
<There are auto top off devices available to top off the tank for you and provide a more consistent environment for your tank inhabitants. Search 'ATO' on the Google search box at the bottom of WetWebMedia.>
My question is, should I be adding something to my top off water? Never thought I had too, but I've read a
couple of places where they recommended adding something to keep the PH up.
<It is possible to buffer the water, but not necessary, assuming you are testing and adjusting alkalinity as needed. Just continue adding topping off your tank with RO water, pH swings will be less noticeable if top offs are done on a small consistent scale like with an ATO. You can also aerate your top off water to remove CO2 from it prior to use.>
Also, how can I be sure that my RO unit is working properly (I have the Coralife Pure-Flo)? Is there something I can use to test the RO water? I was reading about TDS testing but wasn't sure if that was necessary.
<I would highly recommend testing the Total Dissolved Solids from the effluent hose of your RO unit. Membranes do lose their potency over time from normal use, but this can be accelerated depending on what chemicals your city adds to the water. Testing TDS is one of the most simple ways of checking the quality of effluent coming from a RO unit, and basic TDS meters can be had at a very low cost.>
<Your welcome.

Re: Top off water and Testing for RO Water 4/27/09
Thanks Josh. Yes I'm topping off roughly every week. I usually lose close to 10 gallons a week! You make a good point about trying to do it more often to avoid larger swings in specific gravity. I'll definitely try to
do that.
I'll also look into a TDS tester.
Thanks again.
<Your welcome, I think you will come to enjoy not carrying full buckets of water around. Josh>

Tunze Water Level Alarm 11/30/08 Hi. <Hello Mohamed.> I found an interesting equipment online and I was wondering if you know if it is a reliable product.. seems very useful - Tunze Water level alarm. <Tunze will undoubtedly be reliable.> It uses float switches and I don't know how good Tunze's float switch quality is .. <Nothing special, you can get these yourself very easily.> (I've heard good things about the Osmolator) <An excellent product.> .. just wanted to know if this is a good product and if I should go for it.. I need a piece of equipment like this. Is there a product better than this for safety protection in my aquarium for overflow of main tank, run dry for sump and overflow for sump ( a top off would be a great bonus for an all in one unit .. :).. <Hmmm, if you have a gravity fed overflow, with redundancy there is little need for this particular product. If you are looking or an ATO the Osmolator is second to none. Not only does it top off the tank, but it does the same basic functions as the Water Level Alarm. Even if you have no sump the Osmolator is just as good.> I haven't found anything on forums or your search engine regarding this product and just wanted to know how well it performs. <It is new to the US as far as I am aware, but the company is one I stand behind.> Thanks Mohamed. <Welcome, Scott V.>

Mystery Water Loss 9/4/08 Hi Crew!!!!!
<Hello Jay.>
Great website, it has helped me out a great deal, hats off to you guys and gals.
<Great! Thank you.>
I have a 75 Gallon Reef with a 20 Gallon sump, it is a new setup and was running with just saltwater for about a week without any noticeable water loss. Since adding my 28Kg of cured live rock and 20kg live sand and switching on my Tunze 9010 I have noticed a water loss of about 1 Gallon over a 12 hour period, I do not think that it is all due to evaporation because as I understood if saltwater evaporates the salt from the evaporated water would remain in the tank and the salinity would rise?
<A rise in salinity would be expected, but depending on your testing methods it may not be a measurable amount. A good refractometer will be able to measure the difference, but even then it will be very little in this water volume. A gallon in 12 hours is not unheard of.>
I am having the opposite, my salinity is slowly going down, I have checked all piping and bulkheads, I can not even find a drip or even a wet patch.
<If the salinity is indeed going down, you must be losing the water somewhere (and topping off). I however do suspect you may want to try a different hydrometer/refractometer or at least have an LFS test the salinity for you over a period of a few days.>
I have not even started to use my light fixture yet (Arcadia twin 150watt metal halides), so it can't be excessive evaporation, can it?
<It indeed can be. There will be some evaporation, much dependant on ambient temperature. Even just adding the protein skimmer will increase the evaporation.>
My tank parameters are as follows: SG 1.024 - 1.026, PH 8.24, Temp 25.5. I really can not work this one out, any ideas that you may have would be very much appreciated.
<Welcome, Scott V.>

Plumbing Issue 12/19/07 I have a bit of a plumbing issue getting water for water changes into my aquarium. I put a basic diagram together in Visio to understand the issue. First some comments on why this was put together. 1.) I do not want to put more holes in the aquarium, otherwise I'd take the water directly here <Understood.> 2.) I do not want to take water to the sump as the water auto siphons out, put water in the sump and drain it back out, you are not diluting much actual aquarium water by doing water changes, this makes water changes much less effective. <OK> Any ideas to solve the issue on the diagram. I think the issue has something to do w/ the pressure on the line. Bryan Heitman <Your pump should be able to pump the water higher than you show in your diagram. Are you sure your solenoid is truly open? Also, you may want to try shutting off your sump return to see if you get better results. If you are running much flow through your drains it is possibly it is creating too much pressure for your pump to overcome. I hope this helps, good luck, Scott V.>

Salinity and water changes  10/25/07 Hello, I would like to start by saying that your site and staff members have been essential in helping me maintain a healthy saltwater aquarium for many years. <fabulous> I recently upgraded to a 125 gallon tank which I plan to maintain as FOWLR. I have about 150 lbs of LR and a 6 in. live DSB, SG will be kept around 1.022. <This is too low. Although most fish can tolerate lower salinities, the micro-crustaceans and other inverts which put the "live" in live DSB and live rock need a salinity much closer to natural sea water (ideally, 1.024-1.026). Please see here: http://www.wetwebmedia.com/spg_salinity.htm> The tank has been drilled and drains into two connected sumps (30 & 20 gallons respectively). The 30 gallon houses a refugium with a live DSB, LR, and two types of macro algae. The 20 gallon has been divided into two chambers, one with my remora protein skimmer and the other holds a Rio 1300 return pump. My livestock consists of 1 juvenile Koran Angel, 1 Powder Brown Tang, 1 Tiger Wardii Goby, and about 40 Nassarius snails. Since this will be my first adventure with a tank this size, I was seeking your advice concerning husbandry. Given the inhabitants and system, how much water should I change on a weekly basis? <5 to 10% weekly or 20 to 40% monthly. Please see here: http://www.wetwebmedia.com/water.htm> Also, do you recommend keeping the SG relatively low if I do not plan to add corals? <No, please see above.> Thank you for your time and advice. Kiet <De nada, Sara M.>

pH of top-off water  9/23/07 Good morning all, <Kim> As always, thank you so much for sharing your knowledge with all of us out here on the learning curve of this hobby. I have been struggling with maintaining the PH level of my top off water. I have attached the information that I have found on WWM below for reference/background, as this person had the exact same problem I am experiencing. <Okay> I keep about eight gallons of top off at a time right now. Recently I purchased a RO/DI unit, and at the same time I switched from using Kent Marine Buffer over to SeaChem Marine Buffer. Since then I have not been able to keep the PH up in the Top off water. After researching here, I thought that maybe the powerhead I have in the bucket is not strong enough. <Mmm, shouldn't matter> I upped it to a Maxijet 1200, and it hasn't helped at all. I aerate the water with the powerhead, and keep it heated as well. <Good> I also keep a cover on the bucket. If I buffer it to proper PH at night, the next day it is consistently back down below the PH scale. <May need to leave the top off...> Do you have any other suggestions as to what could be wrong? I'm wondering if the process works such that when you add the buffer and test an hour or so later, the test should be off the charts, but settle back the appropriate level the following day? <Usually so, yes> Presently I'm only adding enough buffer to bring it up to the 8.2ish range within an hour or so. As an aside, like the other inquirer, I live in an older home, so it is not super-well insulated. <Actually better most times for air exchange...> Thank you for your time. Regards, Kim in Boston <I would first try leaving the mixing container top ajar for a day... Next I would try adding a teaspoon or two per five gallons of simple baking soda (Sodium Bicarbonate) to see if this moves the pH. Please do re-contact me/us re. Bob Fenner>

Fresh water top offs... SW chem. confusion, not reading...   8/2/07 Hello Bob & Co, My water PH is 8.0. 1. Is it wise to bring the PH of the fresh water I use to compensate for evaporation, to 8.0 by adding baking soda, before topping off? <Yes... but not with sodium or other bicarbonate... need carbonate, other material with higher kOH...> 2. If so, how many teaspoons per gallon of fresh water do I need to add, to raise it from 7 to 8? Cheers, Gans <Please read here: http://wetwebmedia.com/marphalk.htm and the linked files above. Bob Fenner>

Minor Debacle... Automated Top-Off system... snail...  7/14/07 Hi Folks, I chose to automate the aquarium rather than add a refugium this summer. <Mmmm, are the functions of these refugiums automate-able?> In fact, I saw an automatic water top-off (ATO) on sale last summer and purchased it with a priority to free myself. <Okay> There were a few early and difficult choices that determined my current predicament: (1) a rather small 55-gal show glass tank from first marine experience was a fundamental constraint, (2) an annual unbudgeted need for a chiller (with a suspicion that Cyano grows much faster in warmer waters than cooler waters), <This is so in general> and (3) a desire to plan one annual holiday away. <I strongly agree with this last... In fact, with four scheduled trips away... one per quarter... a minimum of time to look forward (in anticipation) and back (in reflection)...> Friends have been great in the past but requires scheduling, planning, coordinating, and luck. Auto seemed to be the way to go. <Mmm, well, our lives are "on auto" to extents in many ways... as well as the minor part which are our avocations...> The summer allows more aquarium time, which is perfect for semi-annual maintenance and upgrades from the previous 12 months of observation and experience. Automation made the most sense as well as advancing the tank to support the growth of stony coral frags. Ricordea, and leathers have flourished. Tripled in size over the past year and are ready for propping themselves. I even have the toothpicks, and super glue ready with a plan on how to maximize the number of new divisions (cultivars?)... gardening is fun too. So, that has been the plan. I set up the ATO and it has been functioning great. I remember reading the design of the sensor reduced problems with snails and frankly, never gave it another thought. I also purchased 2 cobalt-blue moonlights. Flashlight-lit night observations were just too voyeuristic for me. :-) <Heeeee!> So, I placed them on the tank divider and was deciding where best to locate and how best to affix to compact lighting unit. Well, a snail managed to interfere with the operation of the ATO and lucky for me, I woke up to a damp floor. <Yikes> I starting turning on lights, grabbing towels, and making multiple observations about the tank...I still had no idea what was happening. 1. The pumps were working to the filter and the protein skimmer. 2. There was a red sensor on the ATO. 3. All the fish were swimming (key-hole dwarf angel, 6-line wrasse, and 2 PJ cardinals), 4. Frags were on the gravel-bed, 5. All Shrooms, polyps, and leathers were compressed, or constricted. Never have all of the leathers and Shrooms ever compressed at the same time. They had always alternated this compression behavior in the past. So, my immediate reaction was everything seems to be alive...whew! Then I noticed all 5 margarita snails were on the gravel bed and snails gone. (Wrasse?) or the fact that there was a snail on the inside of the ATO shut-off sensor preventing it from cutting off the water pump. As the water rose it submerged the moonlights. Thank goodness for the GFCI, however, it is my assessment that the tank is experiencing a recovery from poor husbandry skills leading to the unexpected environmental JOLT caused by water mixing with electricity. They are both very predictable and formidable forces. <Agreed. Well-stated> I shut-off the ATO. Removed the snail from the sensor. Mopped up the floor...I am so lucky (My summer project 2 years ago was installing laminate flooring in the great room and dining room. The aquarium is in the great room). And tested the tank parameters. Everything was okay...slight elevation of nitrates to 5.0 which had recently been bobbing its head, and a slight rise in ammonium to 0.25. Otherwise, pH (1.024), nitrites and phosphate were zero, alkalinity (9-10), and calcium (340-360) so they were normal. I very healthy and self propagating colony of zoo were only partially compressed and seem to be opening more from day to day. The toadstool leather opened today, even though there is a notable amount mucous around it. The finger leather is still rather compressed. I actually thought it was recovering yesterday, now I am uncertain. A blue lankia <Linckias sometime live in areas where there is sudden, large influx of freshwater> star is moving through the aquarium without visible distress. Astrea and Nassarius snails doing well. However, while doing a scheduled water change I noticed a lot of very small empty snail shells??? <May have died from the sudden lowered spg... been on/in the LR> The Galaxea seems to be the most injured, and I am uncertain whether it will withstand this acute episode of environmental stress. What would have happened to copepods? nanoplankton? other circulating creatures. For that matter, did this event affect algae counts? <Yes... all> Do I need to replace the GFCI? <Mmm, not likely... use the test/re-set buttons... if they work, it's fine> Was the damage limited due to the low wattage of the moonlights or the effectiveness of the GFCI? <Likely both> Although, I believe there was some contributory negligence on the part of the snail, I should have been more cautious with the temporary location of the moonlights. I had some plastic toothpicks and superglue on-hand for another planned project. So, I constructed a snail-guard around the ATO water sensor to prevent this from happening in the future. Perhaps others can benefit from same. <I, we and they thank you> I am not blaming the ATO. I think it is a great and necessary equipment upgrade to manage evaporative loss...for me that is about 0.5-0.75 gal/day. What can I expect in the short and long run. Will I loose all of the creatures slowly? <Likely the worst is over...> Will they survive if they made it this far? Is there a source on the effects of acute environmental distress by electricity in marine aquariums and coral reefs? Something else I should be doing to encourage healing?? <Mmm, slowly (like a thousandth of specific gravity) per day... raising the density of the water... but otherwise, general good husbandry should save the day, your livestock here. Cheers, Bob Fenner>

Big Change: Water Evaporation   6/24/07 Hello WWM, <Hello, GrahamT here tonight!> You are a tremendous resource and we can't thank you enough for the time and effort your whole team puts in to making this wonderful hobby even more enjoyable. The daily questions are a daily read for us - more so than the newspaper. Thank you again. <Thank you for your kind words on behalf of our dedicated crew! I am convinced that reading the dailies... well, daily, can make an advanced hobbyist out of any of us!.> We have a 75 gallon FOWLR which has been running nicely for three years now. As per your recommendation, we upgraded to a Remora Pro skimmer about six weeks ago. This has been maybe the best thing we have ever done for our tank. Producing an incredible amount of the nasty green stuff. <Very good to hear. Some people can fine tune the amount of food they give by the amount of gunk collected in their skimmers.> When we first introduced the skimmer, we had a difficult time keeping the temperature steady as the Mag 3 pump gave us 4-5 degree fluctuation daily. It was easily fixed by adding a small fan blowing across the top of the tank. <Ahh, yes... evaporative cooling can be very useful and economical.> Our tank temperature is now consistent at 76 degrees. The problem we are having is with water evaporation. <Hence the term, "Evaporative cooling".> Before adding the skimmer, we would have to add a couple gallons every couple days or so. Now we have to add three to four gallons per day. <Happens, I'm afraid...> There are no leaks anywhere and we are wondering why this is the case. At first we though maybe it was due to summertime, but we haven't had this issue in the past. <You're experiencing one of the drawbacks to evaporative cooling. Really, there isn't much to say here, since slowing down the evaporation means warming the tank. You should be ok with letting the temps rise slowly to 78-degrees, if you have a lower speed for the fan you use. Other than that, I think you're stuck with it. One thing you need to watch out for with increased water-loss through evaporation is the problem of concentrated "leave-behinds" that are being reintroduced every time you top-off, and as the water leaves, the levels are rising. If you use purified water and perform frequent water changes, this may not be a concern. Food for thought...> Thanks in advance for your help, Tracy and Scott <You are most welcome, folks! -GrahamT>

Freshwater or Saltwater To Replace Water Lost To My Skimmer? - 06/05/07 Should I use RO/DI or seawater for the replacement of the waste water created by my skimmer on my 65g? Skimmer kicks out about a quart of waste every day or two. <<You pose a very good question. One of the fundamental keys to success in the hobby is the ability to provide "stability" to your system. Many authors have/will state that water parameters such as salinity and temperature often don't have to be "spot on" as long as they are stable...though small gradual changes are usually deemed acceptable. But if I may digress a moment...I have been shore-diving off the coast of the Big Island of Hawaii where great quantities of cold, fresh, water were seeping out of the rock in to the ocean. This created stratifications in the water column where the differences in both salinity and temperature were neither small nor gradual...and the fishes appeared little bothered when traversing through one to the other. This doesn't mean I advocate we as hobbyists should be making/allowing large swings in our tank's water parameters...but it is some food for thought. But more to the point of your question...You "can" monitor salinity on a daily basis and make adjustments using a brine solution if you wish to do so, and in some extreme cases this may even be necessary...but for the majority of aquarists, as long as you are monitoring the salinity of your system and making needed adjustments during your water changes, topping off with RO/DI water (preferably buffered) to replace both evaporation and the gradual amounts lost to skimming is perfectly acceptable...in my opinion>> Many thanks in advance. Gene <<Is my pleasure to share. EricR>>

Tap water straight from faucet to aquarium?   4/1/07 HI I use all distilled water for my FOWLR tank, <Careful, some distillers use copper coils.> but recently I took the tops off and switched out for egg crate.  I am experiencing lots of evaporation which is in turn using a lot more of my stored distilled water for water changes.  Can I use un-aged, untreated tap water for my top offs? <I wouldn't. Not only will here be chloramines and heavy metals but unwanted nutrients such as phosphates. AND...depending n where you live a multitude of other nasties, tap is so variable and even when it's to be used it should be aged/treated/aerated.>   My concern of course is chlorine or possibly chloramines but its my understanding in a 75 gallon tank the effects would be so little of adding like 1 gal. that it would not hurt anything? <Yes but the "nasties" mentioned above would add up over time.> I would be nice to be able to get room temp water from the faucet and add it right in.  Thanks. <See above and articles posted on WWM. Adam J.>

Water to use. Tap trtmt 10/03/06 I have a 60 gallon DAS with 65 pounds live rock and 110 pounds live sand. Currently I only have a hammer coral and xenia and some cleaner crews going. The tank has been set up for 2 months. I am having some evaporation. I understand that I need to add some water that does not have salt in it since the salt does not evaporate. My question is Do I have to get RO water or DI water or can I filter my own water through an inline filter that I can get at Lowes or home depot to remove the chlorine and such? <You do need to use RO or DI. I suggest using a system designed for aquarium use. The drinking water systems at the big box stores (or anywhere for the most part) are not a good idea for use in a tank with invertebrates.> Thanks a million, <Very welcome and best of luck - Emerson> Mark

Evaporation Rock  3/22/06 Hello, You all are the best! <Hello! We aim to please> I have a 60g cube FOWLR and I recently added a 1/5hp chiller which successfully brought the temp and the evaporation down. Evaporation was one gallon a day and is now down to half that. <That is a decent reduction, I wish I had that.> I want it even less. I do have live rock sticking out of the water right under the halide. Do you think this is working like a wick and accelerating the evaporation? <It could be, but I don't think so.   However I would make every attempt either to control that evaporation anyway (How about an auto-drip?) but either way you should try to move that rock so it doesn't see air. Desiccation is never a good thing for long periods of time.> Thanks for your response.  <No problem, have a great one.  Jen S.> Sid.

Kalkwasser And Top-Off Systems - 08/08/05 I have a 29 gallon reef with a 175w metal halide and two T5 actinics with a Remora hang-on skimmer and running some Rowaphos in an Aquaclear filter.  My inhabitants are mostly softies, xenia, star, zoos, Ricordea and also some SPS (Stylos, Montipora, stag frag).  I will be upgrading to a 55 gallon corner tank soon. <<neat>> I plan to build a remote sump system in my garage and want to make a dependable freshwater top off system using a 7 gallon container (salt bucket size) filled with R/O water and using a float switch and an Aqualift pump (2-3 gallons per hour). <<ok>>   I have been told I can use Kalk solution in this setup. <<yes>> Basically mix Kalk and 5 gallons of R/O then after it settles, siphon off the water to fill my evap makeup reservoir.  I was told I could run this setup 24 hours a day since it just adds water in small amounts many times a day, just refilling with this Kalk solution once a week or so. <<As needed, yes.>> The next better option may be to use a Kalk reactor??    <<Matter of preference...the reactor is less troublesome in my opinion (easier/quicker to service). Can you help me be smarter about these two setups and how they would work for my tank? Any suggestions or "counseling" is really appreciated. :) <<Well Bob, either would/will work fine.  Many, many folks do what you propose (or similar) with mixing up Kalkwasser solution and using it to top up your tank evaporation.  This is one of the easier/more simple methods for dosing Kalk (aside from Anthony Calfo's slurry method).  My preference is to use a Kalk reactor, but these are more difficult to build/expensive to purchase.  Both methods utilize your makeup reservoir and pump (water is pumped through the reactor) to dose the Kalk, the reactor just does the "mixing" for you.  But don't fret, you don't "need" a reactor, you're original plan sounds fine.  Have a look at our FAQs on water top-off systems: http://www.wetwebmedia.com/h20makeupfaqs.htm>> Thanks Bob <<Regards, EricR>>

Re: Water change - Top Off Strategy  8/27/05 Thanks for the quick response. A follow up if I may. <Sure> I got a new pH pen today and discovered my pH is 7.7. Not 8.1 like the test kit told me! KH is 9.5 and Calcium is 300. Tank is 90 gallons, 7 weeks old with a few soft corals and 3 small tank bred clowns. <Okay> My plan is to use SeaChem Marine Buffer 8.3 (1 teaspoon for 20 gallons) and add Seachem Kalkwasser (1 teaspoon per gallon) to my change water. I will then change 10% of the water per week and hope that the pH starts to climb with the water changes. <Sounds good> Is this reasonable or do I need to take more drastic measures to the tank right away. I am trying not to shock my fish as they all seem happy. <Mmm, no... nothing drastic... not many good things "happen" quickly with marine aquariums> Does the Kalkwasser dosage seem high or do you really need to add that much! <Mmm, depends on a few factors... bio-load mainly, but experimentation is key here... add some, test later...> Do I need to be careful not to siphon of any unused Kalk in the bottom of my water change bucket? <Mmm, no... Please read here: http://www.wetwebmedia.com/kalkh2ofaqs.htm and the linked files above> Sorry for all of the questions but this is very confusing. Thanks. Keith <Keep studying, contemplating... you'll be less confused... Bob Fenner>

Vacation, auto top off Hi Crew, <Aaron> Wanted to thank you guys for your reassurance on some trouble I was having with my colt. I did indeed just leave it, but did remove the necrotic tissue. The sponge was removed, back to a QT, that I will now be forever leery of, and everything is popping back to normal, albeit slowly. Again thanks for the info, I think it was early enough. <Thank you for this update> I will be leaving for the east for about a week this Spring, Baltimore, will visit and take lots of pictures of The Aquarium at the Inner Harbor. I've tried to design my system to be as fool proof (me being the fool most often) as possible. I do keep Anthias, and I have them on Prime Reef and Formula One and Two flakes, mixed. I added a bunch of slots to a pond feeder I have and it starts to distribute food at about 9am and drops little bits in till about 6pm- seems to work ok for 8 days. All the fish eat this, but I usually supplement in the morning and evening with higher quality foods. I figure a week won't kill anybody in this department, although I do feed filter feeders as well every two days. I will be able to have someone come by about every other day, I'm leaving enough food for 3 feedings, that's 6 cubes. I've added six cubes all at once to see what would happen. <Good experiment> Algae's what happens - sooo I'm ok there I think (any suggestions very much appreciated, as I seem to have painted myself into a corner with a tank that no one I know can take care of). Display is 180 gallons, sump is 30, holding about 20, refugium is 45 gallons.  With the light intensity and time of year I'm burning about 3.5 gallons of evaporative water daily, that would mean I'd need a reserve tank of at least 26 gallons, should probably make it closer to thirty. And this is the real questions, sorry for the rant, should I just bite the bullet on this and buy two DC solenoids, run them in series and plumb the sump to the RO unit using the LifeReef floats? <Could> I'm a biomedical engineer, and I tend to err on the side of caution with medical equipment, seems reasonable to do so with marine systems as well since it's technically life support.  <Agreed... am far more a fan here of a restricted source/volume... like car boys... of about thirty gallon total... simple float valving> Anywho, I've neglected to do this because, well, in the hospital, if a dosing pump fails, there's several people available at all times to fix it. It would be REALLY unfortunate to come home and find the house is totally and completely flooded with brackish water, and I'm unaware of any coral that would do very well with a constant influx of sterile water. Sooo the reserve or the plumb, that is the question! <Agreed...> Really appreciate any input.  PS: What came first the Zooxanthellae or the Coral? <The algae> An often argued subject between my wife and myself, she says the algae because they are the primary producers... <One logical approach... also, in terms of "fossil evidence", PCR manipulation history... the Thallophytes are much simpler, pre-date the cnidaria... Look to the popular works of Lynn Margulis here... you will enjoy the speculations as to origins of mitochondria, other endoplasmic inclusions> I say the coral because there are zooxanthellae species in both false and true corals, don't know which of these came first either- so what came first- time- wise? <The Monerans...> Thanks, Aaron and Michelle <Bob Fenner> 

DI water for top off Hello, I have a Kent DI unit that is attached to a float in my sump that automatically replenishes my evaporation water, now this water is not buffered and I suspect it is one reason for my PH staying in the 8.0 to 8.15 range (also run a calcium reactor). I was trying to think of a way to buffer the water without changing my current set up and had a "crazy" idea that I would like to get your opinion on. I was thinking of adding another stage to the DI unit at the end before going to my sump, fill the canister with some media that would dissolve raising the buffer and PH, if I filled the canister with the same media used in my reactor would this work? I know the water is acidic coming from my well and the DI makes it no better so my thoughts are the media would dissolve (just like in my reactor) and therefore buffer my top-off water. Thanks for your time, all comments are appreciated. Thanks <Hello, I think your idea might work but I probably wouldn't go that route.  I would get a aqua doser from Kent or some other similar doser and just dose at night with Kalkwasser.  It will be more easily controlled than trying to use aragonite to buffer the water from your D.I. unit.  Good Luck. MikeB.>

Automated water changes Hi MacL, <HI! Timon> I live in tropical Thailand and the temperature of the room where my refugium and sump are located will vary greatly depending on if the sun shines that day so I am worried that the evaporation rate will vary a lot from day to day. <It might be a problem for corals as well as your tank temp is bound to fluctuate a bit> I have learned today that I can use a conductivity controller that can control a pump based on pre-set minimum and maximum conductivity values. Do you think this is a good way to make up for evaporation?
<I think it might be your only option because of the fluctuations. Please if you decide that's the way to go and it works, Please let me know. MacL> Thanks Timon

RO Top off in a 300 gallon aquarium 9/24/04 I have a 300 gallon aquarium with an additional 75 gallon sump/refugium underneath.  The system is in the high desert in a very dry environment and I am running around 2000 watts of VHO/Halides.   <wow... truly an excessive amount of light even for shallow water SPS corals. No other complaints from me though if you are happy and coral pigments are surprising dark, rich> As a result, I have a very high amount of evaporation.   <with 2K watts of lights... I bet you can see it ripped off as steam <G>> I haven't checked exactly, but it is around 4-5 gallons each day, possibly more during hot, dry days.  I also travel a lot and can't rely upon my wife to top of the tank.  I have relied upon a RO unit, with an automated top-off system based on the level in the sump.  The system works extremely well and I can leave for almost any period of time without worry.  I do small water changes each week and run a calc reactor.   <very good> The calcium level is consistently above 400 and the PH is stable around 8.3.  The problem is that the alkalinity is 2.5 meg, barely acceptable for SPS corals and I am sure that low alkalinity is caused by the RO water, which is pumped directly into the sump. <a small Yikes escapes the lips> Aerating the RO water is not an option because it requires my constant presence.   <ahhh... OK. Or not, mate. DO invest in an infrared float switch or like quality unit. These are in the $100-200 range as float switches go... but are well worth the investment.> Are there other solutions?   <yep... adding/dosing buffer and/or running RO input through a bed of lime/carbonate chips like the second chamber on your Calcium reactor> Are there products that can be added to an RO system or should I simply start adding an alkalinity buffer each week?  Thanks <you have your answers/good intuition my friend. Roll with it. Anthony>

How do I top off water in my Nano Reef? Hi Crew, << Hi there >> I have a 10 gallon saltwater tank. I replace 1 gallon every week. Since the weather has heated up the tank temperature started climbing into the low 80's so I got a small fan which keeps it around 78. But now I get a lot of evaporation, as much as a gallon a week. So I need to add a gallon of new unsalted water.
<< Yep, this is very common, just keep adding freshwater (not from the tap, but dechlorinated of course) as needed to keep the tank level filled. >> Do I still need to remove a gallon and replace it since evaporation does not remove any pollutants? << Yes this top off water doesn't count towards the water changes.  A 10 gal is very easy for water changes, considering one gallon of freshly mixed salt water is a 10% change.  Just be sure to slowly add the new water, make it is well mixed with the correct temperature before hand. >> <<  Blundell  >>

Iodine use Hi I have constructed a 500 gallon system for cryptic filter feeders.   There is an algae scrubber and a skimmer.  I will be importing tunicates, sponges, Dendronephthya, file clams... water movement is via a fast current generated by a large water lift into the scrubber, and a Wave2K.  The system has three tanks and two refugia, so that I can isolate and experiment.      There is an automatic top off unit for RO water.  My question is- is there any problem (other than the controversies about using iodine at all)  with putting the iodine in the freshwater top off tank?
<< I don't think there is a problem, but I would probably dose into the tank. >>
 This would allow continuous infusion.  Also, if no problem, can I also add two part alkalinity/calcium supplement to the same reserve with no interactions (i.e. does iodine precipitate on calcium carbonate)?
<< Well you can't add the two parts of a two part solution together.  You could add buffer to your RO water, or add calcium, but you can't add both.  Soooo, I would suggest dosing iodine and calcium, and adding your buffer to your RO water.  I wouldn't mix calcium or iodine in, because you don't really know what reactions may take place. >> Thank you so much! Charles Matthews <<  Blundell  >>

- Temperature Adjustments in Top-off Water - Hi Crew, Sorry about this question and the answer maybe obvious to some of your readers however, I am going to as since you can never ask a dumb question. <The only dumb questions are the ones that remain unasked.> I like others am losing water to evaporation in my 200 ltr Marine Tank. To Top this off, Can I fill up a 10 liter container with fresh water straight from the tap, add some de-chlorinator and add some boiling water to bring the temperature up, then simply add it to the tank. <You could, but better to let the water sit... bring the temperature up with an aquarium heater. The possibility exists that the heat of the boiling water would either be too much or break down the dechlorinator.> I noticed that my protein skimmer, loves this and starts pumping out what appears to be water (unless the fresh water has a lot of proteins in it). <More likely is the dechlorinator.> So I figure something is just not quite right here. I would be grateful for your thoughts on this. Cheers AO. <Cheers, J -- >

- Top off During Vacation - I'll be going out of town for a little bit this summer and I'm leaving a relative in charge of my tank. <Hooo boy!> I'm not so much worried about feeding but more so about evaporation and the specific gravity. <Yes... is perhaps one of the more difficult things to have non-experienced folks maintain while out of town. I've been burned this way more than once.> I'm preparing about 15 gallons of water, and am going to make it easy on my caretaker to just top-off the tank to a designated level every week. <Yes... easy to just put a piece of tape on the outside of the tank or sump to show the desired water level.> If my Specific Gravity is at 1.0235 what should the specific gravity of the water to be added be? <0.000 - You want top off water to be freshwater.> I'm thinking around 1.020 range, as last time I had a spike in my specific gravity. <Not a good idea... your tank salinity will slowly creep upwards if topped off with saltwater.> Suggestions? <Freshwater will be fine... just add a small amount every day or perhaps every other day.> Thank you very much for your time. -David "A man who goes to sea without a reason would go to hell for a holiday." <Cheers, J -- >

Hello and Thanks again...quick question 5/31/04 I have included some photos this time to aid you in visualizing the tank  setup so you can help me out.....Thanks for taking the time...First question is about auto top off....what is the correct way to do it on a 120 gal. reef and what is the best equipment to do it with...ro/di Tunze Osmolator etc? ro/di to storage container with float valve? Then Tunze Osmolator hooked to storage tank and display or sump to activate auto top off? <I am not a big fan of auto top off devices because of the risk of failure.  I would suggest that whatever delivery method you choose that the water be drawn from a reservoir.  This will limit the amount of water that can run into your system at once if the device sticks open.> Also the second question is about pump sizing...I have included the pictures for this purpose.... <Your pic was not attached, but I will try to do my best without it.> The return pumps... I will have 2...one for each side of the tank and I am looking for 1500 to 1700 gph total between both of them... <Good plan.  Having two pumps offers a nice measure of safety if one fails.> From each pump the return line runs up through the custom overflow box with dual 1 1/2 Durso standpipes (o.d) into a "T" connector one output runs along the upper portion of the tank to the top right rear corner with a ball valve attached to regulate flow....the other part of the t runs down the outside of the overflow box and to the front bottom corner ...second return pump repeats the same sequence on the left side of the tank. (see attached photos) <I think I understand your description.  Be sure that you place at least one outlet very near the surface of the water.  This outlet will allow air to enter and prevent siphoning back to your sump if the pump stops.> taking into consideration the return line layout (3/4 " pvc) what pump would reliably give me the output for that side of the tank to reach a combined total of 1500 to 1700 gph.. <Many submersible or external pumps will fit the bill.  Look for models in the 1000 gph range each to get your desired flow after frictional and head losses.  I am a big fan of Iwaki and GRI for external pumps and Mag-drive and the new Quiet-One for submersibles.> and also how can I stop the tank from draining if the pump fails being that two outputs will be in each front lower corner?  Thank you for your time... <See my comments above about placing outlets near the surface.  Best Regards.  Adam>

Buffering Makeup Water WWM crew, <Hi there! Scott F. here today!> HI I'm new to your site but I have already found a wealth of helpful info. After extensive research of your RO water FAQs I still have a question about buffering fresh RO/DI water.  I hadn't been buffering my raw water, well until about a week ago,  anyway I tried to buffer with ESV ALK booster but the ph would go to 8.6 then slowly fall until it hit 7.2.  Not likening to add more chemicals than necessary I  decided to fill a filter bag with 2# of crushed coral and throw it into my makeup water holding tank. Now the ph stays at 8.0. OK now for question.  Is this an acceptable way to buffer my makeup water? I also have a power head circulating and aerating the tank. THANKS FOR SUCH A GREAT SITE, AARON SCHOTT <Well, Aaron, if it is working for you, why not keep it up! As long as you are using material that is not leaching phosphates or other nasty impurities, I don't see any harm in this practice, myself!>

Treating RO/DI water? 2/13/04 Anthony--I lose a quart a day, that I need to top off. Should I use buffered top off water, or just straight rodi water for a couple of days, since I added to much of SeaChem's buffer already.   Thanks Charlie <its fairly risky my friend. Its a better habit/solution to dilute a chemical imbalance with a water change (as other manipulations of chemistry may have occurred) and then resume with properly aerated and buffered seawater or fresh water for top off. Under almost no circumstance should you use raw, unaerated and/or unbuffered RO/DI/Distilled water for SW aquariums. Too unstable. Anthony>

- Automating SPG/Top-off -  Greetings Oh Great Ones,  I have searched the web (including WWM FAQs) for days and spoken to everyone I know in the hobby with no success so its time to bug you guys!   I am looking for a system to maintain spg in my 125g FOWLR. I want a monitor/RO dosing pump setup but have not been able to find a system that actually monitors SPG. <Hmm... you are looking for conductivity meters - this is the monitor for SPG. That being said, I don't think this is the way you really want to handle top-off. Unfortunately, as you mix in freshwater, the changes in SPG will not be immediately evident to a monitor/control device - you could end up adding much more water than should be before the probe registers the change.>  Most systems I have found (including Tunze...Mmm love my other Tunze stuff) utilize water level, and this is not accurate enough for my needs. <You may not think so, but it is... have been using such a system for a while now - works very well.>  I've only been able to find a couple of electronic SPG monitors, and none allow a away to control a dosing pump.  When my homes heat is on I lose about 1-2g's a day and in summer and the fan over the sump is running I lose the same; otherwise I lose about 1/2g to evap. This is causing a swing of up to .001 a day if I don't top off. Of course I do top off about 3 times daily in an attempt to keep the spg as stable as possible, but babysitting the tank is becoming a serious pain.  Any help would be great! <Take a look at http://www.innovativeaquatics.com/  - they have refurbished, medical dosing pumps with electronic float switches - keeps the top off very consistent.>  Thanks, E  <Cheers, J -- >

Buffer Question <2/1/04) Hi Bob, <Steve Allen covering tonight.> I was wondering about the use of "buffer" additives to the RO water used to replace evaporation from my reef tank. Currently I do not add any buffer materials, but I am considering whether it would be wise to do so. My understanding is evaporation with remove 'n' number of H2O molecules (i.e., pure water evaporates); thus we have lost 2'n' hydrogen atoms. Therefore the top-up water needed to replace this should also be 2n hydrogen atoms, to ensure the effect on System pH is identical. Is my understanding correct? <Merely incomplete. You are not considering the factors that affect free H+ ions. True, pH measures these, but it is buffer that keeps them bound up so the pH stays alkaline in seawater. Otherwise, the tendency is to head to neutral (7.4), or even lower due to organic acids in animal waste. By performing RO on your tapwater, you have removed all of it's buffer capacity. Marine tanks naturally lose buffering capacity (carbonate hardness) over time, requiring replacement. There's a lot of good info available on this subject both at WWM and other web sources such as Advanced Aquarist Online.> If so, does this suggest top-up water should not contain buffer additives? <no> Or is it the case that marine tank pH tends to drift downwards due to the bio-load <yes>, and we are simply using the top-up water as a convenient mechanism to replace hydrogen lost due to the filtration of the System? <Not hydrogen lost. Buffer capacity to keep the H+ ions bound up and maintain the alkaline pH we need.> The reason I ask this question is that my reef tank starts the day at pH7.9 and ends at 8.1. <A reef ought to be kept higher. At or around 8.2 to 8.3 would be better. It would be nice to not have the pH drop below 8.0-8.1. I monitor mine electronically, and it never goes less that 8.1 or higher than 8.3> I am starting to benefit from a newly established reverse lit refugium with a DSB - hopefully my pH will continue to improve as the refugium matures. <Yes, this can help stabilize pH if you have macroalgae in it.> Besides weekly 8% water changes the only "additive" to my system is a calcium reactor. <Also great for replacing buffer.> I try to do without additives as they can prove costly over time, mistakes can be made with application (we are all only human!) and leaving the System to go on holiday becomes a larger burden for the person who looks after the tank. <For those who can afford the initial investment, this is a great way to go. Anthony is big on Kalkwasser. I use the 2-part buffer/calcium from B-Ionic, but the cost of that adds up over time. Someday I'll figure out where to fit a calcium reactor in my system.> If adding a buffer to top-up is the "done thing" in the industry then I will follow suit, but reading through the WWM pages left me uncertain if there was consensus in this area. <No absolute consensus out there.> What is your take on this subject? <IMO, the bottom line here is that you are replenishing the buffer in the tank with your calcium reactor. The reason to buffer your RO water is to replenish its own buffering capacity that was removed by the RO process. I have been very satisfied simply adding the recommended per-gallon dose to my RO water only when making new salt water for water changes. My water is so hard here that I do not seem to need to add buffer to my top-off RO (no DI), which has a pH of 8.8. I'd suggest you check the pH of your top-off. If it is in the pH range you need, then you don't need to buffer it.> As always, thank you very much for your advice. Andrew Senior <Hope this helps. I do not profess to be a chemist. Do read more if you desire a deeper understanding. Here's a start: http://advancedaquarist.com/issues/may2002/chem.htm >

pH problems 1/31/04 Hey, just a quick question for you guys. First of all, thanks for the great website and for all the effort everybody has put into it. It has really helped me through a lot in this sometimes frustrating hobby.. I have searched through all the FAQs on Ph and Alkalinity and couldn't find the answer to my problem. I also searched through the RO sections. I did however find a person with the same problem, but it was never cleared up. Ok, the question.. <Wow! Sounds like you have been quite diligent.> When I make up top-off water I heat and aerate the water for 24 hours to drive off carbonic acid.. I do this in a 5 gallon bucket of old salt mix with a MaxiJet 1200 on the bottom facing upwards to create surface agitation. I have a pump with air stone I use also to make extra sure it aerated good enough.. I then add a half teaspoon of Seachem marine buffer and a half teaspoon of Seachem reef builder. I let this mix and circulate for another 12-24 hours. After about 90 minutes after adding the buffer the water test at 8.4 ... I then waited 7 hours and tested another time.. It tested at 8.2 ... I waited another 7 hours after that and retested. It tested at 7.8.. I have tried opening windows. I have tried aerating for a couple of days prior to mixing and nothing seems to help. I tried mixing for 3 days or so thinking the buffers haven't had time to dissolve totally, but nothing seems so help.. It still falls to 7.4-7.8.. after 24 hours or so. I just can't figure out why the buffer and reef builder is falling out of solution or being eaten up some how. I shouldn't have to add buffer ever day to keep a constant ph level. I just can't figure it out.. Maybe you guys can enlighten me on what's going on. <Two things are occurring in some combination. First, the buffers in these products are actually LESS soluble in fresh water than in salt water (I know this is counter intuitive, but trust me!). Second, the manufacturer puts a variety of chemicals in these products so that long term use does not lead to the accumulation or depletion of certain ions from your aquarium. The combination of these two things will lead to precipitation in your bucket. I suspect that you have noticed a powdery white precipitate in the bottom of your bucket, or the water becomes slightly cloudy. My suggestion is to use these products one at a time (alternate between them) and only add them to the aerated water immediately before use.> I hate to bother ya'll with stuff like this, but it really has been bothering me. I don't want to drive my tanks ph down by adding low ph water. I have read through just about every faq page on the website over the years for knowledge and for when any question arose.. It has been a blessing indeed. Keep up the good work. Thanks in advance, Jeff Trumble <No need to worry about driving your tank pH down. The buffers are still there, and in the CO2 consuming daylight hours in a reef tank, they will resort back to the desired pH. You just won't be getting the most effect for your money. Glad you have found benefit from WWM! Adam>

We Get Rain, Let's Use It! >Hello, >>Hello. >I have a 50g reef tank. I was wondering if using rain water in Los Angeles that comes directly from the sky (not from drains or runoff) is alright to use for make-up water? >>Treat as you would RO/DI (it would be VERY soft, and require proper buffering). >Should I worry about pollutants in the air?  thanks.  Jason >>I would not use the "first rain", but living in L.A. myself, I would think that what we got yesterday would give you quite a bit after the first half hour or so.  I think you can certainly try (do keep an eye on our news stations' air pollution reports for your best information), and if in doubt, filter through carbon and a Polyfilter, then buffer.  Marina

- Shut-off Switch, Follow-up - Hi again Crew, I was able to locate a few vendors who sell such a switch, but I guess my real question is: Is this something I should spend the $$ on?
<To me, peace of mine is often worth paying for.>
 Does this offer me some protection against overflow or is it prone to sticking and causing more problems then not having it?
<Depends on the nature of the float switch. May pay to give it a rinse from time to time.>
Have any of the Crew used this or know about them?
<You left out the important information - what is 'this'? You didn't name the actual product.> Thanks <Cheers, J -- >

Re: sump shut off switch 12/7/03 (2) Crew, Sorry, One that I found is the UltraLife float switch at MarineDepot and premium aquatics. Thanks. - Shut-off Switch, Follow-up - Hi again Crew, I was able to locate a few vendors who sell such a switch, but I guess my real question is: Is this something I should spend the $$ on?  Too me, peace of mine is often worth paying for.  Does this offer me some protection against overflow or is it prone to sticking and causing more problems then not having it? <Depends on the nature of the float switch. May pay to give it a rinse from time to time.>  Have any of the Crew used this or know about them?  <You left out the important information - what is 'this'? You didn't name the actual product.> Thanks <Cheers, J -- >

- Chemical Filtration & Makeup Water Heating - I have done some reading about the two products Chemi-pure and Phos-Zorb.  They sound like really good products for my reef tank.  What I would like to do is place these two in a hang off the side filtration system will they work that way? <Yes.> I have several dual chambered hang off side systems lying around from my cichlid days.  Not worried about unsightliness because I bought a tall tank and stacked the live rock all the way up to the water line.  It gave the tank an interesting effect.  I have fish living in an almost apartment style from top to bottom. I installed mirrors on the wall in back of the tank with dim lights to see what goes on back there.  A lot let me tell you. It's a regular dance club. Complete with bass players and a sand bar.  I also have several corals put on the rocks I took the time to make sure all are secure ( I built little PVC holders custom made for each coral to keep them off of the rocks and out far enough  to let them fully expand and grow.  Very ugly at first but now all are overgrown with coralline algae) I put light lovers at the top, deeper water ones down at the bottom, aggressive corals with plenty of room.  I also have a few anemones in and around the rocks.  Very aggressive skimming a Sea-Clone 100 (I know not the best skimmer, but I made a few modifications on the air inlet valve and now I get a whole lot of brown goo in the cup about every other day.)  The reason I wanted to know about these two products is I use a very simple filtration system.  A gravity flow of water from the bottom of the tank into a modified plastic bucket filled with floss and activated charcoal and a big power head to pump it back up into the tank. I guess really the power head helps suck the water through the filter so it is more of a gravity assisted filter.  It has worked well for over three years, Sea-Clone 8 months,  but I want to do the best I can for my conversation piece (aquarium).    Also I keep 33 gallons of salt water for my every two week ritual of water changes, I only aerate it.  I have been reading that some people heat their water in the container. <I'd be one of those people.> I always thought this to be a grey area. <Not in my mind.> Should I keep all 33 gallons at 78F or heat it just before I use it? <Yes... or at least heat it up a day or two before you use it - adding water that is not temperature matched to the tank can be a source of stress for your animals.> Thanks ahead of time, Craig <Cheers, J -- >

Question from new retailer continued II 10/30/03 That sounds very clever, I like it.  One thing that is kind of confusing me... what is a seawater float... is this different than a regular float switch?   <ahh... my fault my friend. Not clear. Both float switches are the same... by seawater, I mean that one is hooked up to bleed in saltwater (the coarse, fast-tuned one), while the other (the sensitive slow-tuned one) simply bleeds in freshwater for evap top off. Thus a sharp drop in water level (as from sales and siphoned saltwater) will allow the seawater float switch to top of faster than the FW bleed can make a difference. And the sensitive tuned FW bleeding float can feed FW for slow evap while the SW float is tuned to coarse to even sense the slow drop in water level> And thanks for filling my daily need for Bob.  I was getting a little worried when he didn't respond within 60 seconds. <ha! tis the standard we try for <G>> Thanks, Matt <best of luck>

- Top Off System - Hey guys, I have a 75 gallon tank that evaporates about 1 gallon per day (very aggravating). <Have had my own set of aggravating top-off problems.> Several months ago I set up a 5 gallon bucket as a top-off reservoir.  I put a powerhead in the bottom and ran a hose into my sump.  The powerhead plugs into an outlet that I have wired to a switch, when I flip the switch, powerhead comes on.  Beats having to pour water in everyday.  However, I was still having to fill my top-off bucket every four to five days, so, tonight I went to the store and purchased a 30 gallon trash can.  I figured that should hold me for at least 1 month.  I kept the set up the same, however, after topping off my tank I returned one hour later to find 30 gallons of water on the floor. <Fun, not.> It seem that once I turn the power off to the powerhead there is still a siphon. <Yep.> I cut a large hole that would "catch air" breaking the siphon, but it did not work.  How can I set this up for water to only come through when the powerhead is on, not thereafter as well. <Not so easy with a trashcan full of water - even if you were to plumb a through-hull, you'd still have the weight of 30 gallons of water wanting to empty out through the powerhead. If I were you, I'd take a look at the peristaltic pumps available through Innovative Aquatics in Connecticut: http://www.innovativeaquatics.com/ - I purchased one of these units several weeks ago and have been quite satisfied at the results. The unit I chose has a float switch which turns the pump on, and then you can select a rate at which to pump water. The nature of the peristaltic pump does not give way to siphons. The fact that this pump eliminated my top-off problems [unreliable float valve] made it worth every penny.> Thanks so much! <Cheers, J -- >

- DIY Dosing Question - Hey guys :)  I made a DIY drip unit for my top-off water, which will be distilled water buffered to the proper KH.  My question is this-Can I dose Iodine with the buffered water? <I wouldn't.> Can I add gluconate CA to it as well? <You could, but I wouldn't.> I'm no chemist, and don't claim to know anything about it, but it seems as though these could be dripped together in one unit. <They 'could', but I wouldn't - I'd stick with the standard bearers - Kalkwasser or just clean water for top off. As for the iodine - I just wouldn't add this without testing. Gluconate+calcium is not the optimum way to get calcium into your tank, and then leaves you with all those sugars... look out problem algae. So no... I wouldn't bother topping off with either of those.> Thanks guys, you rock. <Cheers, J -- >

-Top-off water questions- Hey Kevin, Mike again, the leaves are starting to change color here in Edmonton so you know that "Winter is a comin". < :( One or two doing that around here too...>I am re-reading and re-reading over articles and FAQ about water changes since this is the number one thing a person can do to provide a good home for the little guys. I was rereading for about the 10th time this article http://www.wetwebmedia.com/water.htm and I am wondering. Do I need to buffer my tap water for water changes to get the pH to be the same as the tank, Target a pH of 8.2-8.6? or do I just have to be concerned about similar temperature, specific gravity and treat to remove chlorine/chloramine? <That would depend on what your test kit reads after you fully salt and aerate the water overnight. Every salt creates a slightly (sometimes not so slightly!) different batch of seawater.> If so/In addition,  baking soda can be used to raise Ph. how much would I use to prepare 5 gallons of pre-mixed water for water changes? <Check the carbonate hardness and pH before toying around with any additives, the salt should contain all you need.> and would you recommend this method? Thanks again Kev. <Good luck, don't forget to break out the long underwear! -Kevin> Cheers. Mike Tol

-Infrared auto top-off by... Tunze?!- WWM Team/Kevin, I wanted to follow up on this question.  Turns out the AquaSense top off monitor is no longer manufactured. <Doh! I should have looked a lil deeper...>  However, I did find one that still is. It's called the "Tunze Osmolator Universal 3155". <I had no idea Tunze had such a product> Here is a review: http://www.pelzer.com/index.html?page=/reef/osmolator.html.  Marine Depot.com sells it.  Now, the big question:  Is this top off monitor worth $165? <After doing a reefcentral search I came up with many positive experiences with this product. The review alludes to a Kalk dispensing "kit" that can be purchased separately, but I didn't see if for sale on marine depot.> Possibly, if hooked up to a Kalk dispenser but I'm way too new to the hobby to offer any "formal" guidance at this time (hopefully soon). Thanks again for your help. <I may try one of these on my own system (was going to use a LiterMeter, don't need float switches getting crusty or clogging up impeller driven pumps) in conjunction with a Kalk reactor (I would assume that if the unit pumped freshwater into the reactor which then made its way into the tank that one wouldn't need the Kalk kit, but who knows...) Cool! -Kevin> Mark

- Infrared Auto Top-off? - I saw on your website that infrared auto top-offs are the best.  Where can I buy products like this?  Thanks! Mark <It took a few Google searches to come up with something, but I came up with a product called AquaSense. Here's some reviews: http://www.saltcorner.com/sections/reviews/productreviews/aquasense.htm by Bob Goemans and http://www.animalnetwork.com/fish/library/articleview2.asp?Section=&RecordNo=185 by Richard Harker. I'd check with Marine Depot b/c I found this  http://www.marinedepot.com/dp_aquasense.htm on their site, but with no price or availability. Good luck and let us know how it goes! -Kevin>

Water Treatment I have just found this site and I am grateful for the archives in Q&A type format. Thanks for all the great info. <Thank you for the kind words! We enjoy bringing it to you! Scott F. with you today!> I live in the United Arab Emirates, in an apartment, with limited space. It would be very handy for me to use bottled water (5 gal. water cooler style) from a local supplier. I have obtained a water quality report (see below). They claim that the water undergoes a RO process. Would you suggest that I buy an additional unit (something cheap and portable like the product shown here --> http://www.drsfostersmith.com/product/prod_Display.cfm?siteid=6  http://www.drsfostersmith.com/product/prod_Display.cfm?siteid=6&pCatId=4484&pCatId=4484   and put the water through another processing for my new marine tank under construction that will house fish and possibly some corals? Would the fact that I plan on regular water changes impact this decision? Thanks. Water Product Specification * pH  @ 25 degrees C = 7.8 8.2 * Conductivity @ 25 degrees C (|uS/cm)  =  95 - 105 * TDS @ 25 degrees C (mg/l)  = 95 - 105 * Total Hardness as CaCo3 (mg/l) =  35 - 45 * Total Alkalinity to pH 4.4 (mg/l) =  45 - 55 * Calcium (mg/l) = 15-20 * Magnesium (mg/l) =  03 - 05 * Sodium (mg/l) =  25 - 35 * Potassium (mg/l) =  0.5 - 0.7 * Bicarbonate (mg/l) =  55 - 65 * Chloride (mg/l) =  20 - 30 * Sulphate (mg/l) =  05 - 10 * Fluoride (mg/l)  =  0.45 - 0.55 * Total & free Chlorine (mg/l)  =  Nil * Turbidity (NTU) =  Nil * Taste & Odor  = Acceptable/Good Carolyn Munson <Well, Carolyn- your water looks to be pretty good, however, I'd highly recommend further treatment via an RO/DI unit. This is the best way to obtain consistent, high quality water. Hope this helps! Regards, Scott F>

- Buffering Top-off - <Good morning, JasonC here...> I was just told by another experienced reefer, that he does not buffer his top off water in a reef tank... using ro/di top off. He is using a calcium reactor. Are calcium reactors typically automated to the extent that they make up for the acidic top off. <No... calcium reactors are fed from the tank and return to the tank, and essentially a zero-gain when it comes to water additions. Likewise the effluent from a calcium reactor is about pH 6.7 so not buffering the top-off is not a good plan.> I am planning my set up, and I would like to plan a vacation so that the wife does not yell at me for not wanting to do anything but pet fishing. Therefore I am trying to plan my top off H20 for a 10 day excursion. I have dripped Kalk before, but at the 3 gallons a day I will most likely evaporate, I do not have anyone that I could trust to secure my system in my absence. <Time to find them... look perhaps for a tank maintenance company.> Any thoughts would be appreciated. <You might also consider filling a garbage can with top-off water and using a float valve to do the work in your absence. Test this before you leave town, but should work. Cheers, J -- >

- Re: Buffering Top-off - So I suppose I treat/buffer the garbage can water, then I still drip Kalk or make a Kalk slurry. <Yes.> Does a Kalk reactor provide a better auto system. <I think that is how Kalkwasser reactors are intended to be used, but given that you evaporate three gallons a day, that's a lot of Kalkwasser to be adding. I would stick with normal top-off and then supplement that, but not use a Kalkwasser reactor exclusively. Cheers, J -- >

Evaporation effects >Re: my 55 gallon acrylic marine tank: when water evaporates, what goes with it? >>Pretty much H2O. >How bout ammonia, nitrates, phosphate, calcium, magnesium, iodine, etc. >>No, those are not evaporated away, especially the mineral substances. >And what are the benefits or disadvantages of having your tank mostly uncovered (power compact lights are maybe 4-5 inches above water level with high powered fan cooling everything)? >>The biggest disadvantages are losing fish (the jumpers), though this can be prevented by utilizing fiberglass/plastic window screening, and evaporation.  However, this is offset (significantly so) by the cooling effect of evaporation (it's much easier, technologically speaking, to heat a tank than to cool it), and the ease of gas exchange (O2xCO2) at the water's surface. >Also, it is true that if you have a window open your tanks pH will rise a bit, if so, why is that? >>This has to do with the pH lowering effects of CO2 (carbon dioxide), often experienced in closed up rooms with poor ventilation.  In Nordic countries this can become a significant issue, *especially* if heating is achieved via wood fire. >Ok, last question.  If marijuana smoking occurs within tank proximity, what are the possible detriments?   >>I have found that there are no detrimental effects observed (pers. exp.).  Of course, this is assuming that the room itself is relatively well-ventilated (no "Up in Smoke" recreations, please).  Cigarette or cigar smoke may pose more of a problem, ESPECIALLY if foam fractionation using a venturi-type air inlet is being used, as the smoke from the air can conceivably be pulled into the reaction chamber.  But with the wacky tobaccy, I think at worst your fishes will be feelin' a little groovy.  They may get the munchies, so have some Nori and other good-for-them snacks on hand, eh? >Your council's wisdom is precious to me.. >>This crewmember has spoken, the council may weigh in with other information.  Best of luck to you!  Marina

Top off system Hi All, Thanks for the help in the past.  I owe all my knowledge and successes gained in this hobby to Bob, Anthony, Craig and rest of the Crew! <Glad we could help my friend!> Anyway, on the topic of RO make up water to replace evaporation in my reef, I understand the benefit of buffering it before use - since the PH is very low (around 6). <And Alk too!> My concern is this: I am using a daily 2-part buffering system that maintains my Ca and Alk param.s perfectly.  My top up is dripped in 24/7 using an automated system with a float switch, so there are no sudden PH swings (I understand the risk of using such systems, but I'm willing to accept it because it makes my life a whole lot easier and the hobby much more enjoyable). <If this works well for your system then I would stick with it. You *are* dosing both parts A and B separately, (as per the label) *right*?  Likely using the buffer part *alone* as the drip to "stabilize" pH? This is okay.> In my case, is the risk even that severe anyway?  Am I correct to say that all 4 gallons of RO @ 6PH dumped in at once would drop the PH in 90gallon system @8.2 down to about 8.1. If this is about right, it doesn't sound too critical to me. <If one considers pH only. Not too much to worry! What happens to your temp, salinity, alkalinity, calcium, etc. when you dump 4 or 5 gallons of cold RO water into your system?  The effect is dependent on overall volume, (and where it's released) which is why I sent you to the DIY pages to size your top off volume to your overall volume in case such an event were to take place. Consider all water param.s in this case to be safe!>   I calculated this as follows: 5% Total Vol. 6PH 95% Total Vol. 8.2 PH 50/50 would bring PH down to about 7.1 or for calculation purposes, we'll use 1 full point. Divide by 10 to get 5% and we get .1 - is this a good enough calculation? I personally see that in my case buffering my top up a moot issue.  I agree that in the event all my top-up gets dumped in at once (i.e. during a failure) the impact would be less with buffered water, but other than that is it really required?  Doing so will just make the effort of maintaining consistent and balanced Ca/dKH more difficult - not to mention the added costs and time of doing so since my tank evaporates about a gallon a day. Thoughts always appreciated! Steve <Your system will likely evaporate more than a gallon per day in the summer months, do consider using Kalkwasser dripped to maintain calcium/pH and periodic additions of buffer/carbonate alkalinity supplements as opposed to two part additives in larger systems like a 90....very expensive unless ease of use is paramount, in which case, continue on mate. At any rate, 4-5 gallons of cold, unbuffered water into 90 gallons could/would be problematic in proportion to how fast (and where) it is released. Through a float valve into a sump, overall, not much to worry about....unless it floods. Even then, in view of how much water I can put on the floor, 4-5 gallons is a slap on the wrist! No worries!  Craig>

Buffering RO for Top Off Dear crew: If I would like to hook up a RO unit through a solenoid and a float switch to replace my evaporated water, do I need to add buffer to the new RO water before I add into the sump?? Or can I even just hook up the water line without the RO?? Will that be ok? Eric <Hi Eric,  Because RO removes most to all mineral content, the resulting product is acidic, in the pH 6 range. This water should be reconstituted or buffered to raise pH and supplement the lost carbonates in reef systems, unless it will be used to mix Kalkwasser (then use it as is).  I recommend running the RO into a secondary container, like a Rubbermaid tub or trash can and running a solenoid or float switch for a pump or gravity feed into your sump. There are several good plans for these on the web, search for them at WetWebMedia.Com under top off systems and DIY. The best system I have seen, used a float valve, gravity fed with a limited supply, (sized to the system) so a failure wouldn't have overwhelmingly negative impact.  A solenoid or float valve failure will then only introduce so much top off water. Many people periodically add buffered water to supplement carbonates but mainly top off by dripping  Kalkwasser which you don't want to buffer. Many options available including several commercially available systems.  Check out some of our sponsors for these. Yours, Craig>  

Evaporation top off systems Help Please! I have a 125 reef tank with ecosystem filter.  I evaporate a little over 1 gallon per day due to cooling fans.  A local fish store recommended a cheap way to add evaporated water would be to use a vacuum pump.  The vacuum pump would take water from a 10 gallon tank and with a timer, pump water into the filter.  I plan to use a power head to circulate and aerate the 10 gallon reservoir tank.  Does this sound like a good idea? <I would go to this page and look at several ideas... http://www.ozreef.org/diy/index.html#TOP_UP > Can I add my additives to the 10 gallon reservoir tank?  Steve. <Some can be dosed together and some not. Depends on which additives you use. Follow label, do not mix carbonate Alk/buffer and calcium/mag/strontium/Kalkwasser in any case.  Take care that your top off can't overflow your system or overdose additives/FW.  Craig>

Evaporation Situation! Hi, <Hi there! Scott F. with you today> Thank you for all of the great info that you provide.  I searched through the FAQs, but I couldn't find an answer. <Okay- let's give it a whirl! LOL> I have a question that I hope you can answer for me.  I have a 90 gal SPS coral tank with metal halide lighting.  It evaporates approximately 1.5 to 2 gallons of water daily which maintains a 24 hr temperature between 78 and 80 degrees.  This water is replaced with RO ozonized water buffered with Seachem buffer.  All tank inhabitants are doing great and I have not had any temp related diseases such as ich.  Is this too much evaporation? <Well, any evaporation is too much, as far as we are concerned, right? However, in an open-topped tank with halide lighting, the usual reef pumps, etc., it seems pretty typical, actually> Should I invest in a chiller? <A chiller will help keep your tank temperature at acceptable levels, but it will not prevent evaporation. Your tank temperature and fluctuation seem quite acceptable. Short of hermitically sealing the tank (not an option!), diligent top-off seems to be the best way to go... Some people design and install automatic top-off systems, but they scare the heck out of me, really (I have no less than 4 friends who have had outright catastrophes, ranging from flooded homes to complete wipe-outs as a result of malfunctioning automatic top-off systems.> Thanks in advance for your response! Cheri Pawlak <My pleasure, Cheri. Just keep on top of things, and your tan

Auto Top-Offs -Jason, <Good evening...> I've reviewed as much info as I could find on your site regarding auto top offs and my primary concern is the failure of a valve or switch. <I think perhaps I wasn't entirely clear - I was trying to convince you into a different 'way' to change the water; not in small, constant amounts, but in one fell-swoop - more akin to using buckets, but also incorporating your desire to use these tanks. I do not propose you go full-blown auto top-off, but rather crank the valves by hand.> How reliable are the Kent float valves. <They work.> What's the most reliable switch? I like the simplicity of a float valve but it would be difficult to build in redundancy as one could by using multiple switches. <Again... these items add unnecessary complication - consider just putting a hand valve where you might use a float switch.> Regards, George <Cheers, J -- >

- Re: Semi-Auto Top off - Jason, <Good morning.> You were clear as far as your water change recommendation, thanks. <Oh good - sometime I worry that I prattle on too much.> Seems like I read a reply from one of the crew that said that some commercial breeders and public aquariums use a slow, constant exchange method and that it was superior, but I am convinced that I need to stick with the simpler method you suggest. Likewise, I thought that small, frequent automatic top off amounts were better than introducing larger amounts of fresh water to the system less frequently, but I am paranoid about failed float valves or float switches. <Don't blame you there...> Think I'll stick with a manual top off system as well. Can't wait to get the nuts and bolts issues out of the way soon and start talking about animals. <Sounds good.> Many thanks, George <Cheers, J -- >

Top Offs... Thanks for all of your answers! <Glad to be of service! Scott F. with you again!> Is it OK if I keep forwarding the previous message so that you will remember my set-up? <It's fine with me, but we usually can't print the previous messages in the interest of space..> One more question about the refugium. <sure!> If I grow macro-algae within 16 inches from the surface what sort of lighting should I use? Coralife makes some 10 watt 50/50 that screw into a normal 110V light bulb socket. If these would work well in this application, how many should I use?  If this was your refugium what would you use? <I use compact fluorescents. I think that 2- 32 watt, or 2- 65 watt bulbs would be just fine> Last question for today. I use RO water for everything, and like I stated before it tested out at 4ppm dissolved solids (quite well I was told).  Could there still be phosphates in this water that is fueling Cyano algae? <Could be. The dissolved solids could be just about anything, unfortunately. It does not take too much phosphate to generate nuisance algae growth, so it is possible. If the membranes on the RO unit need replacing, it's possible that undesirables are getting through...check them! Also, use of good chemical filtration media, such as Poly Filter, will help remove excess phosphate and other impurities from the water once it's in your system...> Also what is your opinion on automatic top-up devices (float devices) inside a sump? <Honestly, they scare the hell out of me! Sure, they work, and there are many well-constructed systems out there. But I have had a few friends who have experienced outright catastrophes from malfunctioning units over the years. I am of the old-fashioned, labor-intensive, haul-the-water-in-a-bucket school of water top off! If you are a DIYer, check out the great site Ozreef for some better plans> Will this cause a problem, seeing that the water is not aerated or buffered? <Frankly, I think that it's better to prep the water before adding it to the tank or auto-top-off system> If I do add water via this method is it OK to just compensate with buffer to keep ph and alkalinity up?        <I'd treat it like any other source water that you'd use in the tank. Hope this helps! Regards, Scott F>

Can you make a recommendation on the automatic top off? Right now my R/O unit goes to a 80 gallon reservoir which I will use for my premix. I was thinking of teeing off the existing supply to the 80-gallon reservoir to the sump and controlling the flow with a Kent marine float valve.  In other words, the R/O unit would feed both the 80-gallon reservoir and another line directly to the sump.  Kent marine, however, does not recommend having a float valve in the sump connected directly to the R/O unit.  for some reason this is bad for the solenoid, since the constant evaporation from the sump will keep the R/O unit working constantly or at least turning the solenoid on and off constantly. The recommendation was to get yet another reservoir to which I would periodically pump water from the existing 80-gallon reservoir.  This second reservoir would be solely for fresh water and would gravity feed the sump and be controlled by a float valve.  This second reservoir would have to be refilled every week or so, so the automatic top-off would not be fully automatic, just automated during the week. Any thoughts on this would be appreciated. <There are two ways to do this depending on your system. The above system allows you to buffer your top-off water as needed, but is less automated. The opposite idea works as well, automated with dosing pumps, calcium reactors, etc. You need two containers as above. The main reservoir is fed by the RO unit controlled by the Kent float. The pre-mix container should be the container that is periodically filled when needed, not the top-off. The top-off system can then be run with a small pump in the main reservoir, controlled by a solenoid in the sump (either DIY or one of the commercially available units) which refills the sump automatically. Check out marine set-ups at WetWebMedia.com  Craig>

Re: automatic top-off Two perceived advantages of not using the main reservoir as the automatic top off:   (1) The R/O unit isn't running all the time from the constant dribble replacing evaporation from the sump;   <This is a non-issue, RO's that feed drinking water tanks have the same intervals/use.  It will run as long as required to fill the reservoir, regardless.> (2) in the event of malfunction, only a limited amount of fresh water gets dumped in the tank. <This is a good reason to go with the gravity fed top-off of limited volume, only so much water can be accidentally added to the system.> What the perceived advantages of what you propose?  Solely automation?  The task of refilling the automatic top off seems hardly burdensome.  It's a flip of the switch. <I got the feeling you were concerned with automation, if not, I would go with what works best, is safest for you and your inhabitants. Enjoy!  Craig>

Automated water changes for mini-reef Hello, and thanks for the great website and instructive information. <thanks kindly... please keep reading, learning and sharing> I'm interested in attempting the following experiment: to maintain a 180 gal. community mini-reef system with automated water changes from the regeneration (the rinse water that cleanses the ion-exchange resin bed)  from my household water softener. <I see some likely problems already if your household softener uses potassium or sodium chloride to recharge: imparting chlorides which skew alkalinity in the aquarium for post treated water... OR...(your case) the impart of hardened "purged water" which has mostly useful hard water elements (exchanged for chloride by the softener) BUT(!) also has un-exchanged sodium chloride. This unregulated NaCl allowed into your aquarium without  the other balanced minerals and trace elements of seawater will naturally effect your SG but without the other necessary elements. In simpler terms... you can add enough NaCl table salt to a glass of water that gives you a desired reading for marine life, but without the trace elements... marine life will die in this salted water even though the hydrometer says differently> We use a 38,000 grain "on demand" water softener (using sodium chloride) <Houston we have a problem...> and a RO system. (THE RO brine is used for another application -- a humidifying water fountain). The hardness of our municipal tap water is approx. 16 grains. It is chlorinated, but has low (undetectable) total dissolved solid, phosphate, copper and iron content. Each regeneration uses approx 35 gallons, and regenerates approx. every 5 days. Approximately 3lbs of salt is used for each regeneration: <Ughh> The water chemistry of this "brine"  consists mostly of sodium chloride, calcium and magnesium. <Oh, ya!> I have 2 pH readings, 8.1 and 8.2 I'd like to have this water run through some activated carbon and a specified amount of additional synthetic sea salt -- before it hits the sump. <sorry... how do you reckon the incidental plain salt carried in? Even if you could easily measure it, do you really want to get into making your own synthetic trace element slurry to dose and temper the stray plain NaCl?> The tank would be appropriately fitted for overflow drainage. <way too complicated here, bud. Your best bet would be to get a separate (small is OK) 2-column de-ionizer and completely demineralize this water if your goal is saving water. The high pH of this effluent that will be lost through the DI is a small loss and easily/cheaply recovered post treatment> The issues, as I see it are as follows: 1: Maintaining the specific gravity of the tank by fine-tuning the requisite additional salt; (including fiddling with the evaporation rate, by changing the amt. of uncovered surface area.) <a complete nightmare... complicated and recommended only if you enjoy the challenge and are a chemist> 2: Accounting for an accelerated removal of trace elements (strontium, etc.). <accelerated? They were never there in the first place. Not sure we are on the same page here. I am talking about you reckoning the sodium chloride that you are bringing in with this rinse water but without the slurry of balanced trace elements to make SW> Before I reinvent the wheel, do you have any information about other attempts in this area? <no one bothers when time and expense are issues. This would have to be a personal challenge for you, because there is no practical reason otherwise for doing it. The irony is that your tap water through carbon is probably the best water could you have in the house for a marine tank. Reconstituting pure DI water is probably second.> Are there any flies in the ointment I'm missing? <a whole swamp full of flies, brother!> Other considerations? <this really all boils down to not bringing plain salt into the make up water or being a brilliant chemist with a lab to check the daily/weekly variances and compensate for them with your own home-made synthetic sea salt mix> -- e.g. are there some reef species that would be more tolerant to this? <cruel and unnatural to do so... doesn't happen in the wild> Species to avoid? <Ha!... All<G>> Are there other automations to help minimize other tank maintenance, <I can forward you a chapter from my book about setting up automatic water changes with solenoids> such as substrate maintenance? <thin substrate, strong water movement and active sand sifting animals> What other issues should I consider? <hmmm... I'd suggest that you try treating this more like a hobby instead of a science, my friend :) ... unless you truly enjoy the science more than the organic living components (our fishes and corals!)> Thanks!-Frank Pogoda BTW: I plan to keep a journal on this project & publish my results to help others who may be curious about this operation.   <indeed, that would be excellent at any rate. Kind regards, Anthony>

Automated water changes for mini-reef Whew! I haven't been sobered up that aggressively since college mid-terms! <Ha! With a college flashback like that, did you also suddenly get the munchies too? And for lack of a beer at hand, chug your scalding hot coffee chanting "Go. go...go...go...GOOOOOO!" in your head? Just checking?> Your sense of humor and gracious style, Anthony, is why when you ring in folks like me (and you sure did) we laugh along....good job! And thanks for the good feedback. <Wow... thanks kindly :) But I was really just taking the long way around the barn for calling you a sadist with mad scientist tendencies. I'll take the credit just the same <G>. Heehee...> Your reasonable protestations aside, let's assume I (pigheadedly!) go through with this experiment. <OK> Should I seek out a SW product that is markedly higher in balanced trace elements than others? <that depends on how involved you want to get here. If the science of it isn't appeal in the purist form... and you just simply want to make it work: my advice would be to simply purchase the semi-solid synthetic sea salt concentrates they make for the big commercial operations (actually quite economical... but you must mix every time EXTREMELY well or make whole batches (400gall) at a time). These SW slurries have everything in it you need except plain salt. Then... you will only have to calculate the influx of sodium chloride with the source water and supplement proportionately> Is there a trace element compound available without sodium chloride? <yep... most of the big manufacturers make it. Best to seek an aquaculture supply house for this. Fritz used to make such a product for public aquariums and shrimp/food fish farmers.. perhaps still do?> Maybe the trace element/SW slurry (including the correct amount of salt to balance the brine) could be set below the activated charcoal/carbon, ready to be washed into the tank with the regenerated water. What other suggestions do you have to make this work? <Jack Daniels... by the gallon> I know using that automating a system with inferior water  is complicated, ultimately may not work, and is repugnant to many. But the allure of utilizing water that is so close to ideal, and is generated a mere 5 feet away from the tank, and can lop off a HUGE chunk of time, and is an intriguing alternative to the conventional way -- is all too enticing for me. <some merit to it, some extra complications too. The high pH and high mineral content are easily provided/supplemented and cheaply too otherwise. You may find that using this water is not time saving at all, and simply resort to carbon filtered tap water> BTW, I will NOT jeopardize any marine wildlife with this Dr. Demento contraption. <understood my friend> Live rock will be added only when I can easily maintain the correct SW chemistry. Finally, I agree with your suggestion that I treat this more as a hobby than as a science. That's what I'm doing! Rather than anally adhering to scientific rules set in stone, I'm trying a different path to the same destination. <you're a heroin addict, aren't you? Ahem,... I mean... "Why yes, I concur wholeheartedly with your reason and rationale for embracing the science of aquariology without becoming enslaved to it." Errrh... or something like that <G>> From where I sit, my friend, that's the approach that makes mini-reefkeeping a hobby. Thanks again, and do let me know your additional input to this unconventional approach to make and maintain safe sea water. With great appreciation, Frank <best regards in this endeavor... we'll watch for you on the news. :) Anthony>

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