RO/DI Aeration – 04/06/08
Crew,
<<Matt>>
I just have a quick question for you today.
<<Okay>>
I just hooked up my RO/DI unite from Thefilterguys.biz and was wondering what you meant by "aeration".
<<Aerating the newly filtered water helps to expel CO2 and oxygenate the water>>
Can I just put a powerhead in the tub of salt and top off water for circulation, or do I actually need an airstone also?
<<Water circulation, in the form of a powerhead, is quite acceptable. Anything that moves/disrupts the surface of the water will aid in gas exchange>>
Thanks for your help,
Matt
<<Happy to assist. EricR>>

RO/DI Question…Flush-Valve? – 03/26/08
I just have a very quick question for you all today.
<<Okay>>
I am going to buy an RO/DI unit this week from AirWaterIce.com.
<<Nice gear>>
My tank is only 55 gallons, so I do not need a ton of water which means that this unit will not be on all that often.
<<Mmm, I guess that depends on the size of your water storage containers/your husbandry practices…but I would still think you would use it at least once a week>>
I have heard that is not good to let it sit without being in use.
<<If for long periods, no…but if the unit will be run a time or two each week it will be fine>>
Because of this, I was wondering if it would be smart to buy one with an automatic flush on it because it will be sitting?
<<Hmm, I don’t know of any “automatic flush” devices for these units…though I guess if you had a servo to turn the valve and a solenoid to control water flow…….. The flush device is likely “manual,” regardless of its name…but yes, flushing the membrane before each use will increase its longevity, no matter how often you use it>>
Thanks for your input.
Matthew Diethorn
<<Happy to share. Eric Russell>>

Reverse Osmosis water with minerals 01/08/2008
<<Hello, Andrew here>>
I recently purchased blue mushrooms and three weeks has passed and I'm beginning to notice some of the mushrooms are detaching from the live rock. I think this all began when I added reverse osmosis water with minerals for daily top offs. The minerals are sodium bicarbonate and sodium sulfate. I probably should of pay more attention when I bought the water. <<Very true>> What should I do? please help.
<<I would do a couple of 25% water change, 2 days in between changes, with standard RO or RO/DI with nothing added to it. Monitor the Shrooms for changes>>
<<Thanks, A Nixon>>

Finally Got a RODI!! - 03/24/07
Hello all,
<<Hey David>>
I hate asking questions with such a plethora of info to be found here.  But after hunting I'm still unsure of what practices to employ after installing my RODI unit.
<<No worries...let's see if we can figure it out>>
I have dumped the first ten gallons as told to do per instructions.
<<Ok>>
Now I'm wondering since I have read of so many other people adding different stuff such as buffers, etc to the RODI water, what are the MAIN things I should test for and possibly have to add along with salt mix to my new water?
<<Well David, I use to indiscriminately buffer my filtered water "prior" to adding the salt mix with a mixture of sodium bicarbonate and Seachem's Reef Buffer (3 to 1).  But of late I've changed my routine and add my salt mix first, then test/add buffer as "needed."  I think you'll find if you do it this way you will precipitate less alkaline material out of solution from overdosing buffer>>
We have Wisconsin well water that tests wonderfully each year for drinking purposes.  It is run through a sediment filter and a softener which I had been using straight from there.
<<Hmm, has always been my understanding that it is not good to use water from a "softened" source as it loads the water with Na+ and Cl- ions which will eventually create an imbalance>>
I added salt mix and just poured it in, no buffer or anything added with no worries.  This has been for years now and I've always been worried my water is the source of a phosphate problem. (no tests done just the signs have been seen).
<<Possibly...but you should "test" rather than speculate>>
Now I have the RODI located at a bar sink after the softener.
<<Very good>>
I'm pretty sure I have read this is what would be the best setup for my situation.
<<Is...in "my" opinion>>
SOOO what’s next?...
<<Sounds like it's time to filter some water and let it "age">>
Is the RODI going to change the water so much that I should test for things I never tested for before?
<<You should test calcium/alkalinity/pH of your mixed saltwater...but not just because you added the RODI unit...>>
I have only tested for nitrates, nitrites, and CA in the past (all safe).
<<Very good, though use of the filter unit should preclude having to test for nitrogenous compounds except in cases where you may suspect the efficacy of the filter membrane/DI resin>>
Short of food I add nothing to the tank.  All seems well but when I pour in this new (pure) water what can I expect?
<<Mmm, perhaps a healthier more "balanced" system...ultimately>>
Is my skimmer going to freak out?
<<No>>
My fish? corals?
<<No and no again...as long as you don't go nuts and try to do an 80% water change...do keep/use the water-change routine you've already established>>
Is the hardness going to dive to a unacceptable level?
<<...?  As in a precipitous event?...not from using filtered water.  Just make sure you measure and buffer (if even necessary) your alkalinity to safe/normal NSW levels>>
Any foresight from the ones with 20/20 hindsight??
<<I very much recommend you continue reading through our information on water filtration, marine alkalinity, mixing and supplementing artificial seawater, and marine water chemistry/constituents in general.  I've listed some for your  review and to get you started>>
http://www.wetwebmedia.com/h2opurifiers.htm  http://www.wetwebmedia.com/alkalinity.htm  
http://www.wetwebmedia.com/seah2omixing.htm  
http://www.wetwebmedia.com/seah2osuppl.htm  
http://www.wetwebmedia.com/seah2omats.htm
Thank you,
David Conway
<<Read-on my friend.  Eric Russell>>

PRIME (SEACHEM) 3/11/07
How are you all doing?
<Good thanks.>
I have a question about the product PRIME from Seachem. I have a little system made to dispense Freshwater (R/O) from a 26 gallon trash can and a saltwater mix (1.023) that is in another 26 gallon. I have heaters in both and have power heads in both. My question is when I make new fresh water with the R/O maker, can I just implement the PRIME in the freshwater trash can? <Not necessary with R/O water, it removes the chemicals Prime treats.> Or when I'm ready to mix new saltwater and add it to my saltwater trash can should I put the PRIME in the saltwater mix? Where do you think the Prime would be more effective or does it even matter? <Unnecessary.> Sorry but two more question my tank has been cycling for two weeks now and I have been doing 5-10% water changes so far at the end of each week ( Only two so far).
However, I also have real fine sand in the tank. Do I need to siphon the sand too. <I would not unless it has algae growth on it.> Or can I just pick up the die off from my LR with tongs and not have to stir up the sand. <Would work fine.> Because as you know if you suck to close to the sand you end up sucking up sand as well and I don't want to do that. The last question I have is my tank has already gone through a phase where I had brown algae and now it has turned green in the tank is this normal? <Yes> I  believe it is from all of the books and forums I read on this web site. Also can you all give me a good web site to go to that has detailed info on how the Nitrogen cycle works and the steps your tank goes through from beginning to end and also charts and pictures of what it looks like in these stages.  <Don't know of one with everything you are looking for.  Can start here http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm and see where it leads you.>   
Thank you for all of your help!
Jeff
<Chris>

pH stored water   12/22/06
Hello Crew
<Wayne>
Sorry if this is a repeat question, but I can't seem to find the answer on your site.
<Let's see if "it's" there... or add it>
I use RODI water and store it in a 30 gal trash can.  I use SeaChem's reef Buffer.  The directions on the bottle don't indicate how much buffer to add to fresh water.
<Is variable... depending on need, the make-up of source water... need to experiment...>
It only makes suggestions on how to add to your main tank.  
So after some trial and error, I've been adding 2 tbls per 30 gal of fresh water.  If I add more, I get cloudy water when I mix salt.  If I add less, than the PH never even gets past 7.8.
<Mmmm... your RODI water... how are you "treating" it period? That is, do you aerate it after making it up in the bucket? Ahead of the buffer addition? I would>
About 8 hours after mixing the Buffer, the PH is off the charts!  Bright purple, I can't even guess what reading this would be.  The highest my test kit goes is 8.8.  It's way beyond that.  Wait another 8 hrs, and the reading drops to 8.0 maybe less.
<Mmm... aerate the water first... consider, try adding a simple bicarbonate buffer first (a few teaspoons of baking soda) allow this to mix for a few hours...>
Any explanations for this?
<CO2/acidic interaction>
How long should buffered water be able to be stored and still maintain a good PH?
<Several weeks...>
What can I do to change this?
<See above>
I have an Aquaclear 50 powerhead, airstone, and heater in the mixing tank (trash can).
<Good>
Thanks for your help.
Wayne
<Thank you. Bob Fenner>

Buffering RO/DI   2/14/06
Hello Crew,
<Tom>
There are a lot of answers on your site that suggest one should age, then buffer, RO/DI water before using it to make Instant Ocean and presumably before adding it as top-off water.
<Yes, this routine is best>
What I am not sure about is if this applies when using a two-part alkalinity/calcium supplement (C-Balance).
<Mmm, best to add just one of these in the make-up water, and drip/place the other in the main tank...>
Specifically, this is my current situation:
Generally, I age, but do not buffer, RO/DI water that I use to make Instant Ocean and to top-off for evaporation loss.  However, my alkalinity had been low for a while (6.0-7.0 dKH), so for a couple weeks now I have been using a teaspoon of Seachem Reef Carbonate per gallon of water used to top-off.
<A good product, technique>
As of this morning, I have alkalinity of 8.0-8.3 dKH and calcium of 330-350 ppm (Salifert tests).  That looks pretty well balanced, though both numbers are near the low ends of what Anthony considers optimal (8-12 dKH and 350-425 ppm).
<Yes>
At this point, should I just use the two-part alkalinity/calcium supplement daily, and not buffer my RO/DI water?  Or would you recommend buffering?
Thanks,
Tom
<I would try the buffering for now... along with the abundant biomineral and alkalinity in your salt mix brand (IO) this ought to get you about where you want to go, be. Bob Fenner>

Buffering RO Water   3/16/06
Hi guys.
<<and Gals>>
I looked on your great site (and even in desperation resorted to others how dare me) <<G>> for two hours and couldn't find a definitive answer so I have to bother you with a question which I am thanking you in advance for answering.
<<No bother friend>>
I recently went with an RO unit because my well water is "sub par"
<<Not uncommon>>
and now my pH in my reef tank has dropped from a steady  8.2 / 8.3 to 7.8.
<<Not the "well's" fault, can happen on "city" water too...generally an issue with tank maintenance/husbandry.>>
Now I have not been buffering my make up water (1/2 to 1 gal per day)
<<Well there ya go <grin>.>>
because I read that in my hundred gallons it should not make that much of a difference but I am now thinking it does and I missed something somewhere.
<<Mmm, probably not a direct result of the top-off water alone...unless you have sufficient "buffering" compounds available (substrate/live rock/water changes/supplements) to the tank on a daily basis the pH will naturally become depressed.>>
I do aerate and heat the RO water for several days however my question is about buffering it.
<<Ok>>
Everyone seems to rave about the SeaChem buffering product however call me slow but I would just like to use Kalkwasser as I have read that will work.  I also read baking soda works too.
<<Indeed...I use the Seachem Reef Buffer myself for buffering my water for my salt mix, though I cut this 3to1 with baking soda to reduce the amount of borate added...and to save a penny or two.  I use Kalkwasser to buffer my top-off, through the use of a Kalkwasser reactor and an auto top-off system.>>
Now my question.  I could find no where as to how much Kalk and/or baking soda or what the procedure is.  I am sure I missed it but I gave her a good go trying to find the answer.  I do not want to foul this up as I have read of the deadly Kalk Overdose Snowstorm and want to avoid that at all costs.  So......do you add the Kalk to the aerated heated RO water till you get the PH to level you want and then dump in as the make up water or does it still need to be dripped slowly.  Or is that even the procedure?  What about the baking soda?  How much per gallon?  Or should I just get with the program and use the SeaChem product.
<<I think some experimentation is in order on your part here.  For buffering with Kalkwasser, a 1/4 teaspoon per gallon is a good starting point.  Any result with a pH of 9 or less should be fine considering you are adding 1% or less of the tank's volume.  For buffering with baking soda, start with a teaspoon per gallon and adjust as necessary.  I would aerate the water for 24 hrs. after adding the baking soda before checking pH to blow off the carbon dioxide present in the baking soda.  Or...f you decide this is all too much hassle, just follow the directions on the Seachem product.>>
I would love to make my contribution by helping you guys answering e-mails for all the help you have given me but I don't think I am there yet.  Thanks again and you guys rock for your dedication to this hobby and answering these questions.
<<I am pleased to be a part of it all.>>
John
<<Regards, EricR>>

Buffering RO/DI water  - 03/11/2006
Hi there!
<Hello>
I try not to write until I spend a few days researching my question and come up empty.  Well, I’m empty!!  :-)
I recently purchased a RO/DI unit and TDS meter.  The water is registering 0.00 on the meter which I am sure is what it should be.
<Yes>
  When I make up my salt water for changes, it’s ph is 8.2.  I have another 5 gal bucket for top off water (tank is only 30).  I use Seachem’s Marine Buffer to prepare the water for top off.  After the pure water is in the bucket I put in ¼
teaspoon of the marine buffer (as per directions after some division) and aerate it for 12-24 hrs.  When I check the ph, it is 9.5ish.  I have tried taking some water out and adding more RO/DI water, but it doesn’t come down more than a point or 2 after changing over ½ the water in the bucket.  How bad is this for my tank?
<If only a small percentage of total volume (less than ten-fifteen or so), not likely a big deal>
I really needed to get the specific gravity down,
<Easy enough to do...>
so I didn’t have time to play chemist anymore.  The bottle of marine buffer says that it will not go over 8.3 even if accidentally overdosed, but I have proven this wrong.  Or does it mean that when it is put in the salt water it will adjust itself and the tank to 8.3?
<Should be closer, yes>
I am really confused.  Please help.
Thanks,
Donna
<Over time, with aeration especially the buffered RO should be closer to 8.2... best to store for a week or more before using. Bob Fenner>

RO/DI...Misapplication/Buffering/pH - 08/09/06
Dear Crew:
<<Lloyd>>
Hi.  I just set up my first marine tank over the last two weeks and have some issues.
<<I see>>
The tank is a 180, and will be a FOWLR if I can ever get to that point.
<<Let's see what I can do to help you get there>>
I filled it with tap water, which is relatively clean, but hard.  Alkalinity was at 300 KH and pH at 8.4.  I treated it with Amquel Plus, added Oceanic salt, (SG is .019), and put in 120 pounds of CaribSea Geo Marine crushed coral with aragonite.
<<I know this is a FOWLR system, but I really think you should increase the salinity to natural seawater levels (1.025/.026).  If parasitic infection is a concern then arm yourself with a quarantine system and read up on/perform freshwater dips when transferring your fish, but don't subject them to a continuous hyposalinity environment in the display.  Think about it, another term for hyposalinity is OST or Osmotic "Shock" Therapy...it has its uses for some short-term treatments, but not as a permanent environmental element.  Your fish will exhibit better behaviors, colors, and "long-term" health in my opinion if kept at a salt concentration closer to/matching that from which they came>>
I washed the gravel extensively but still have somewhat cloudy water.  Should I use water clarifiers or just filter it out mechanically with a 50 micron pad?
<<Nix on the clarifiers...you can use the filter pad if you wish, or just wait for the "dust" to settle on its own...usually a matter of days>>
My more distressing issue is with pH.  I have been reading a great deal in the FAQ's regarding the use of RO/DI units and how they affect water quality.
<<Can...if misused>>
While I certainly may have missed something, (yes, I used the search tool), I seem to be finding conflicting information.
<<Differing opinions abound>>
I am currently running RO/DI water directly into my sump to top off one to two gallons per day as a result of evaporation.
<<Yikes!  This is an example of "misuse"...adding raw unbuffered RO water to your system contributes to the rapid depletion of buffering elements as your system tries to make up for what the newly added water lacks>>
I read that this is an acceptable practice,
<<Mmm, no...not in my opinion...a recipe for trouble>>
however, my pH has dropped into the 7.4 range and the alkalinity is at about 80-100 KH.
<<And there is your proof my friend.  If you are going to run the RO/DI water directly to the tank then run it through a Kalkwasser reactor first...else I recommend you discontinue this practice and store/aerate/buffer the water in a separate container before adding to your system>>
I have also read that processed water often has a very low pH and that it should be aerated to dissipate CO2, which "consumes" alkalinity, which would seem to confirm my problem.
<<Aerating/dissipating CO2 will provide a small increase in pH, but you will still likely need to give it a boost...and you still need to boost/buffer alkalinity>>
I'm a bit confused.
<<Have you read here:  http://www.wetwebmedia.com/marphalk.htm >>
By the way, I'm using Jungle 5 in 1 test strips, so I'm not positive about how accurate these are.  
<<Useless...low quality/inaccurate, too easily affected/corrupted by atmospheric moisture.  Do look to Hach, Salifert, and Seachem for good test kits>>
I have a reservoir for mixing salt water and would prefer to use tap water, mixed and aged, for water changes only and continue to run the RO/DI water directly into the sump with the use of a float valve.
<<Depending on the water in your area using tap water for a FOWLR system is quite possible, but running the raw RO.DI to your sump for top-off is not...in my humble opinion and for reasons you have already experienced>>
This will allow me to minimize my use of the filtration unit and save having multiple floats and pumps, while still maintaining an automated top-off.
<<But at the expense of system stability an the associated detrimental affects on your livestock>>
Should I use additives to raise pH and alkalinity or is there a better method?
<<Using additives to "continually" adjust pH and alkalinity in your system creates a roller-coaster effect that will surely have deleterious affect on your livestock.  The "better method" is to adjust pH/alkalinity prior to adding the water>>
I have a general aversion to using additives of any kind and seem to remember reading that manipulating levels in this manner is to be avoided.
<<Indeed>>
What to do?
<<Already stated>>
Thanks for any help that you may provide.  I had hoped to not bother you with an e-mail and find answers on my own, but the more I read, the more overwhelmed I am with the vast amount of information.
<<No worries mate...am here to help>>
I have been reading on your site for a year prior to undertaking this project.  I also refer frequently to Bob's "Conscientious Marine Aquarist".
<<Ah, very good...but don't limit yourself to a single source of information.  You've already noticed the differences in opinion just on this site...best to gather/learn from differing sources and use your own good judgment to make a decision>>
Both have been outstanding sources of information and I appreciate the time and dedication that all of you put into this hobby, or in your case, profession.
<<Mmm, not my vocation but more an avocation...no "expert" here, merely a "student" of the hobby>>
Thanks again,
Lloyd H.
Columbia, MO
<<Happy to assist.  Regards, EricR in Columbia SC>>

KATI/ANI Unit Woes
Hello one and all-
<Twice in one day! Back again, Ryan>
I was looking you some advice from you fine people. I had recently purchased a Kati/Ani unit for my 125gal fowler(170gal total system). System has been running for 2 years. I have 2 MAG 12 pumps for circulating the water.
For new water when I was using the deionizer) I add "Prime" chlorine remover, aerate, heat for a few days, then add salt then buffer if needed. I would check ph and alk.  I have had dozens of snails in the tank for about a year and now they have almost all died over the past 2 months. Plus my xenia that had been growing like a weed just fell apart. Now the tank has turned into a huge Cyanobacteria farm. All I can think of that has changed is using the new Kati/Ani unit. The resin in the unit has only changed color about 1/3 of the way after running a hundred or so gallons thru it, so I don't think that the resins  would be a problem.  Plus I have a monitor on the water output. I am thinking maybe my process for treating the deionized water is flawed somehow and a ph or alkalinity swing has killed off the snails and xenia.  Could you share with me how you would suggest preparing and testing it?
<I have never used a KATI/ANI unit, but I found a great article about preparing water using one:
http://www.pmas.org/pro/ credit due to Mr. Steven Pro, of course.  His steps are detailed, efficient, and his success evident.>
I have read before that using "Prime" chlorine remover can make some water tests inaccurate? Would it throw of my ph and alk tests? <Never heard this, perhaps the manufacturer can verify?  Message boards like ReefCentral.com chemistry forum would be your best bet on this type of subject.>
I also upgraded from a Berlin turbo skimmer to a Precision Marine Bullet 1. Easily get a cup a week of pretty dark skimmate. <Great>
Are there any  tips you might have for using a deionizer? I have switched back to good old tap water for now until I am sure what is going on. Not sure if this is even part of the problem. My guess is that I should stick with the deionized water because now it seems like it is getting worse. <I would change as little as possible...and do lots of small water changes until you get a handle on this.>
Also- What color would a poly-filter turn if there were phosphates? When I use one it always turn brown pretty fast.
<Poly filter color chart is on the back of the package...sorry bud but I'm at work! (Shh....)>
I am poor at putting thoughts into words, sorry if this is e-mail wanders all over the place.
<No worries.  You'll get this under control, just keep eliminating possibilities and the result will be the cause.>
Thanks for your time.  Dennis

Buffering RO/DI water 5/27/04
Hi Marina,
<Anthony Calfo instead>
Is the Kent Marine Pro Buffer dKH sufficient to reconstitute RODI water? 
<most any common sea buffer will work fine. Do aerate in advance to reduce the amount of buffer needed>
Or should I be looking at another product. 
<I personally like Aquarium Systems SeaBuffer and most any SeaChem products. I've never been a fan of Kent products>
thanks, I understand you are shorthanded, so I will wait patiently for a reply (well at least I will try to wait patiently:) thanks for your support.
<best of luck, Anthony>

- Buffering RO/DI -
Hi, Hope all is going well for you there.  I have a couple of questions please.  First, I use D/I water which I store in a 50 gallon plastic container.  I have read that R/O water should be aerated for 24 hours before adding the salt mix.  Is this also true for D/I? <Yes.> Also, I use Seachem's marine buffer.  Should I add this to my water before or after I add the salt? <Before.> And lastly, what action can I take if a particular batch of salt mixes to a higher than normal ph? <Limit the amount of buffer you add before you add the salt.> I use instant ocean, and have read that at times it can mix to higher ph than normal. <More likely due to differences in the source water and not the salt itself. Test everything before you make additions.> Thank you for your time, James
<Cheers, J -- >

R/O-DI...HEAD SPINNING - 08/06/05
Hello Guys,
<<Morning>>
Been reading your site from start for my salt water set up, it's great and I don't know where I'd be without it.
<<Thank you, glad you find it useful.>>
I am gathering all the components before I start anything.  I want to use a DI unit, my water is well water and very hard.  Iron stains all over the house.  But now I read I may be removing helpful things from my water, is this true?  Please help a rookie in the hobby.
<<No real concern here, the DI unit will provide more help than harm.  Just be sure to buffer the output water before use (simple baking soda...or my personal fave, 2 parts baking soda to one part Seachem Reef Buffer).>>
THANK-YOU DAN PALMISANO
<<Regards, EricR>>

Buffer Dosage - 08/08/05
Thank you for all your help and fast reply.  The buffer you described never mentioned the water ratio, or do I follow the ratio on the Reef Buffer?
""Just be sure to buffer the output water before use (simple baking soda...or my personal fave, 2 parts baking soda to one part Seachem Reef Buffer)""
Thank-you in advance DanP
<<I would start with the dosage recommended for the Reef Buffer alone...test this for alk...then adjust as needed.  EricR>>

Conditioning RO/DI Water 08/26/05
I have a 55 gallon saltwater aquarium set up for 2 yrs now.  I just purchased a ro/di system and want to know what do I need to do to water before I put in tank? <<Congratulations. IMO, RO/DI systems are one of the best investments you can make. The water from the RO/DI unit can be used directly as top-off water. You can also use it for water changes. Just mix with salt and age.>> I was told to use Kalkwasser but not sure about how to use it. <<Kalkwasser is made by adding quicklime or lime to water. The Kalkwasser solution is then added to a system as top-off water or in dosing systems. Using Kalkwasser is one method to supplement calcium and alkalinity (carbonate) to your system. There are several reasons to use Kalkwasser: supplement calcium (reef life use calcium so in a closed system with stony corals, calcium is being depleted), raise the alkalinity to buffer the pH in the system and precipitate out phosphate (which is good for algae and bad for reef keepers). There is lots of material here on this topic. Please search and read up on these topics: Kalkwasser, Kalkwasser slurry and top-off systems.>> I was also told by separate source to use Kent Marine Superbuffer-dKH. Will the Superbuffer be sufficient to use. <<Since you are asking about both Kalkwasser and Kent's Superbuffer, I'm guessing that you have an issue with alkalinity and pH. There are pros and cons associated with using Kalkwasser versus a product like Kent Superbuffer. Considerations include cost and simplicity. Using Superbuffer is simple but in the long wrong, more expensive than Kalkwasser or Kalkwasser slurry. Kalkwasser dosing systems can be fairly simple or more complex and of course the initial cost varies. Kalkwasser slurry is very simple but not for everyone.
Search and read up on Kalkwasser slurry, top-off systems, dosing systems, Nurce, Nilsen Reactor.>> Of course I know to get salinity right. <<Not a worry. Getting the salinity right is what you already do when changing water. The only difference is you will be using better water in your water changes.>> This ro/di has me all thrown off some, how soon can I add this water to tank. Can I add it as soon as I add buffer and get salt and temp right?<< I hope I have cleared up some of your confusion. Again, RO/DI water is great for replacing water that has evaporated from your system. As make-up water, it goes directly into the tank without mixing salt or buffering. For water changes, RO/DI is much better than tap water. Do what you already do and mix the salt water and let it age before doing the water change. Don't add anything to it. Finally, there are many ways to address alkalinity and pH issues. Don't forget to read up and understand why alkalinity and pH are important to your system. Good luck and cheers - Ted>>

Re: Conditioning RO/DI Water 08/26/05
I have no pH or alkalinity problem. I have had nitrate and brown diatom problems.
<<Using RO/DI water is one of the first things to do to combat algae and diatom problems.>> What do you mean by age water? <<Unless you are dealing with some kind of tank emergency and you don't have the opportunity to age the water you
should mix up saltwater to the correct specific gravity and temperature and aerate/circulate it for a day or so before putting it into your system. The
better salt water mixes contain a buffer so adding a buffer is not necessary.>>
So I can take my RO/DI water and put it directly into the tank at temperature without adding anything to it? <<I see from my previous answer, I added to your confusion. Sorry. Yes. Many auto top off systems put RO/DI water directly into the tank. If the RO/DI water feeds a Nilsen reactor, then the addition of buffer is unnecessary. On the other hand, if you store the RO/DI water or place it into a reservoir to feed a top off system, you can aerate and/or buffer the water>> It has very low pH so I figured I would at least use pH buffer for top off water? <<Many people recommend aerating the water to drive off excess CO2 or adding a buffer to RO/DI water to raise the pH before use. You can also make your own buffer using washing and baking soda. Search WWM for more information. Cheers - Ted>>

RO water applications - 8/11/03
Thanks for your advice Mr. Calfo!, or  anyone else that may reply!!
<always welcome>
I wondered if you would mind just clarifying a couple of points you made. With regards to aerating RO water before you use it, what is the reason and why would there be Carbonic Acid/ or CO2 in it in the first place?  
<natural acidity post-demineralization. When you hear about "temporary" pH and its adjustment... this is what they are referring to. Although you can (and should) aerate the RO/DI water to raise the pH... the water still is unstable (could go acidic again easily) because of the lack of ALK/hardness>
Is it part of the filtration process?, and also how long would you recommend to aerate the water for?.
<12-24 hours>
Secondly, if you do not aerate the RO water sufficiently before demineralizing and adding salt will the carbonic acid eventually be driven off with sufficient aeration/movement, or would  it be to tightly bound for it to be driven off, thus resulting in the poorly buffered water as mentioned.
<if you neglect to aerate it and buffer it before using it as evap top-off or for salting, you will find that this water puts a measurable burden (consumption) of the main system's ALK and/or pH>
I ask this because it was my practice to mix salt & minerals and then aerate which I suspect is the reason for my depressed!! pH!! and my depression!!
<yes... at least contributory. Do adjust your water treatment, mate>
and seeing as though I have just filled my new tank with RO water, (purchased as ?5a bottle) aerated after salt has been added, (another great little tip from my soon not to be LFS), I feel,  I might have a more stable tank temp wise, but in exactly the same place as I was before with the pH!!!! Aghh
<yes, indeed.... the problem is not severe, but simply a waste of buffers in the main display which causes these nagging problems>
Then if this being the case should I start more water changes with the properly aerated, water, or just stick to my regular routine?
<hmmm... not sure I follow the question. If its a matter of RO vs. Tap water, I would always recommend properly aerated and remineralized RO or DI water over even the best tap water. Stability/consistency vs. risk of seasonal changes to your source water>
Last but not least, should you remineralise the RO water every time you use it or, only after two or three water changes due to build up of minerals?
<with every use... even if only in a small amount. Let your tests of pH and ALK over time determine how much to use>
That it!! Thanks a million for your advise and help, Rob
<best regards, Anthony>

Explain This to Me Like I'm a 3rd Grader!!!
A few questions please...I've been scouring your site for a few months now... I read your articles/FAQs on alkalinity and pH. If your water is hard, does that mean pH is high and alkalinity is high..? 
<usually they are hand in hand... although it is very possible to have a high pH and low ALK (unstable water)> 
... or does water softness have different effects on chemistry?  LFS guy says since my water is R/O I don't need to aerate my 5 gallons of top off water that I go through every week (stored in plastic 'Red Sea' 5 gallon container with screw tight cap and air- escape- capped- hole- nozzle- thing stored in my food pantry throughout the week, but I like to shake it up a tad during the walk with it to the aquarium).  
<all RO water has to be aerated before it is buffered and used for any purpose>
Out of the 10 LFS's or so in my area, they were the only one who could answer detailed questions about their R/O setup, and it looked good with extra chambers for stuff, one specifically for silicates, and the store's been open less than a year (aquatic aggression in Fresno California) am I doing this wrong?
<without aerating... you wasted buffers. Not a crime... but not good practice either>
Do I need to aerate R/O water from the LFS, they claim to buffer with Kalk and use Red Sea salt??
<do a pH test to confirm the need or not: test the pH and then aerate vigorously for 6-12 hours and then test again... the pH should not change. If it raises, you need to aerate it indeed>
Also, I use the Via-aqua protein skimmer, it has a built in UV that I have now turned off thanks to Anthony....as I'm supporting a mandarin......okay, okay....2 mandarins, 1 male 1 female, both fat and sassy and beginning to get their freak on...no other fish.... it also has a chamber for a mechanical filter pad (laced w/ carbon).  I only used the last one for a week.  I have thrown in some small live rock pieces into this chamber (maybe a gallon of water) with some Gracilaria, it's maybe 3-4 inches wide and 12 inches deep or so....you know, ' fuge style... I don't think I'll put sand in there though.  But I need a small submersible light (for reverse photo period) to dip in here that will complete the ' fuge and keep the Gracilaria alive.  do they sell such lights???   
<there are some neat daylight colored LEDs hitting the market. Also some pool and garden pond lights to do this job are available>
I really feel it's a legit 'fuge.  whaddya think??
<if it's fishless... it's a 'fuge to me <G>>
Considering you're my most trusted authority!! thanks!! I love you guys... and Marina too!! (wink wink)
<who-ha... Antoine>

RO Redux...
Why is it necessary to buffer RO/DI water?
I recently read this on your site......
********************************
Source Water Pre-Treatment
So if I don't wait 24 hours before adding salt this can interfere with my
alkalinity?
<Essentially, yes. Freshly-"produced" RO/DI water has very little, if any buffering capacity, and additions of large quantities of this water, without some form of buffering, can contribute to depleted alkalinity in your system. I think it's good practice to aerate and/or buffer RO or RO/DI water at least 12-24 hours before use. Hope this helps! Regards, Scott F>
********************************
http://www.wetwebmedia.com/rofaq5.htm
after researching and asking some groups, I posted this and asked for some opinions......I came across this response....and I wanted to know if there was any truth to what this guy is saying....
********************************
Yes, it's wrong....When water evaporates from your tank, only pure water is evaporating.  Alkalinity is not evaporating.  Nothing else is evaporating.
<True, but the point is- if alkalinity is being depleted by other sources, using water with no buffering capacity will not help the situation....>
So, simply topping off with pure RO water will have no effect on the buffering capacity of the tank.
<As stated above- in general, this statement is true...But the point is, once again, that in a situation with already depleted alkalinity, the effect could be detrimental..>
I think what this guy is seeing, is that something was using up the alkalinity, possibly from coral growth, and he's just blindly blaming it on the RO water.
<Wrong>
If you notice your alkalinity dropping, you can either use a buffer, I believe Kent and SeaChem both have one, but you must be careful.  Adding a buffering supplement only, could have a negative effect on your calcium levels.
<Potentially true...But may be taken out of the context of the original conversation here...>
The other alternative is to drip Kalkwasser for all your top off water. Kalk will add the alkalinity and calcium at the proper proportions, while keeping pH up where it should be.  The only drawback is that it must be added slowly, otherwise it could push your pH up through the roof.
<I caution against using Kalkwasser to make up water lost to evaporation, as you will be at the mercy of the atmosphere (i.e.; the evaporation rate) to determine your calcium dosing. Better to test water regularly and determine your system's needs rather than just randomly dose Kalkwasser. Kalk is great stuff, but, like anything you add to aquarium water, it's important to test, then tweak, as John Tullock is fond of saying...Hope this clarifies things a bit...Regards, Scott F>
********************************
Thanks,  Keith

- RO/DI Preparation -
Hi,
I have another question. <Ok.> I have purchased an RODI unit.  Is it best to add salt, then buffer (if needed), then calcium (Kalkwasser)? <I would add buffer before the salt.> Or is it better to add the calcium straight to the tank. <And yes, I'd add the calcium directly to your system.> What I'm thinking is that I should get the water ready to go at all the optimum levels, Salinity ~ 1.024, KH~10, Calcium~400 ppm and then use that water as part of a water change.  Would you agree? <Not really - best to add calcium to your tank directly, otherwise buffer the RO/DI water before adding salt.>
Thanks,
-Brent
<Cheers, J -- >

Evaporation Chemistry
Hello,
A quick first question or two from a long time reader.
<Welcome back>
If water lost to evaporation is mostly pure water then why do I need to buffer the DI water I use to replace the lost water? Don't the buffers stay in the tank when water evaporates?
<Mmm, they get "used up"... very basically (bad pun), the overall reactions in closed systems are reductive (as in Redox)... they tend toward making the water more acidic... in effect exhausting the alkaline reserve>
Second, how do I determine how much buffer to put in the DI make up water? I'm using Seachem Marine Buffer per a recommendation in one of the FAQs.
<Best way is to measure your water (new) and try adding your buffering product/s with testing... per your particular livestock, desires for GH, dKH...>
Thanks for providing such a terrific service to all new folks.
Regards,
Jim C
<Thank you for your participation. Bob Fenner>

- Water Prep -
Hello All-
Thanks for looking at yet another question from a saltwater newbie!
I just got a 5 stage RO/DI unit for water changes for my saltwater tank.
I am little confused as to the process of water preparation...What exactly does aerating mean?  Do I simply put new water in my trash can and heat and let it sit for 24 hours?  Do I have to leave the lid off? Do I have to use an air stone? <Add the air stone, I'd leave the lid on, and let it bubble for at least 24 hours.>
I plan to put new water in trash can, heat and run powerhead for 24 hours, then add salt and let mix for another 24 hours.  All of this will be with the lid on, is this wrong? <No... I leave the lid on so that bugs, dust, and whatnot stay out of the water.> I will then test for PH and alk, and add Seachem Reef BUFFER/BUILDER accordingly. <I'd add the buffer ahead of the salt - it's a safe bet that the RO/DI water will need it.><<RMF would add, if necessary, later... AFTER the salt mix is dissolved, the water tested.>>
Please let me know if this process is not correct.
Thanks in advance,
Jeff
<Cheers, J -- >

- Which Water to Use? -
Hello Bob. <Actually, it's JasonC today.> I recently read the WWM article dated 4/99 - http://www.wetwebmedia.com/water4maruse.htm
I am struggling with the planning for my 120G reef tank and the issue of what water to use, Tap, RO, RO/DI or DI. Should I read the above info to mean that it is a good idea to pre-mix synthetic salt mix and my tap water and store for a week or more and it would then be safe to use in my reef tank? <Sure - it's what I did.> Additionally would this be as good/better than to use DI processed tap water? <What is good - what is better? If it means less work for you, or less money spent on an RO/DI unit, then perhaps using tap water is 'good' for you. It's your time - use it as you see fit.>
If yes to the above, could I assume it is equally safe to store my tap water for same period and pre-mix with salt 24 hours prior to water changes? <I'd let things stew a little longer than that... I would mix/aerate the tap water for 48 hours, add the salt, and let that mix for 24 hours, then check/adjust your salinity and let that go for another 24 hours - so a total of about four days. In fact, it's time for me to go fill up the mixing container - thanks for the reminder.>
Thank you for you assistance.
<Cheers, J -- >

Treating Purified Water for Marine Use 6/10/03
Thank you Anthony. I will heed your advice on the NSW.
<very good, my friend>
Unclear on the top off water. I do aerate before.
<yes... critical to raise temp pH and drive off carbonic acid/CO2>
Not sure on the buffer. I use DI water that I purchase from one of the local fish warehouses. What do I need to do for buffering FW?
Thanks again, John
<just a little bit of SeaBuffer (mostly sodium bicarb) to reconstitute the demineralized water a bit. Else the soft purified water will consume excess buffers in the sea salt mix or main aquarium and cause your ALK to be flat/low. Use your test kits (Ca, ALK, pH) as a guide to know how much... and do browse through our archives here at wetwebmedia on the subject. A keyword search of water treatment/RO/DI/buffers with the google search tool on our home page will turn up many many FAQs of interest. Kind regards, Anthony>

Buffering RO/DI water & Going to the Source
Hi Crew,
<Thomas>
I spent many hours on WWM archives trying to sort out questions about buffering RO/DI water before (or after) adding salt mix. I believe the WWM archives actually contain contradictory views on this, and certainly views contradictory to what I was told by the manufacturers of Instant Ocean and B-Ionic.
<They do>
I had an email exchange with the manufacturer of Instant Ocean and a phone conversation with the manufacturer of B-Ionic.
<Hello to Bob>
Below I quote the text of the email exchange with Instant Ocean that documents both these communications. (I did not just forward the email, so as not to divulge others' names and email addresses without their permission.)
<I understand. You are welcome to show them mine>
Make of it what you will. (I would think Anthony, in particular, should see this, as he clearly expresses a contrary opinion -- for example in CalcFAQs3 search for "unbuffered DI or RO").
<Will send all to him>
I'm inclined at this point to believe there is no reason to buffer RO/DI water before mixing with salt or replacing evaporation loss. If that's really a misguided position, please let me know.
Tom
<In almost all cases I am in agreement with your statement. Bob Fenner>
****************
My original message to Instant Ocean:
Hi,
I use Instant Ocean.
I recently got an RO/DI unit to get pure water to start with.
Now I heat and aerate the RO/DI water for at least 8 hours. Then I add the Instant Ocean and heat and aerate this for at least 24 hours (usually more). I also use the RO/DI water directly for evaporation top-up.
Question: Do you recommend adding some marine buffer to the RO/DI water?
If so, would you add it before or after the Instant Ocean? Would you recommend adding the buffer to the RO/DI top-up water, even if not to the water used to make salt water.
Thanks,
Tom
Reply from Instant Ocean: 
Instant Ocean is formulated to provide all of the necessary buffer as is; you should not need to add buffer to freshly prepared seawater. In order to add buffer properly you need to know what your alkalinity is. I would suggest purchasing an alkalinity test kit so you can monitor alkalinity and know if you need to add buffer or not.
Thank you
My Reply back to Instant Ocean:
Thanks.
I do have an alkalinity test kit, and do monitor the tank, using B-ionic to adjust the alkalinity level.
However, I'd read some stuff on the web that suggested RO/DI water, being stripped of virtually all dissolved solids, needs to be reconstituted back to something more "normal" before adding synthetic salt. Otherwise the buffers in the synthetic salt would be "used up" immediately.
But I also got an opinion from the technical support person at B-ionic that synthetic salts are formulated to work with pure water (e.g. RO/DI water) and that using water with significant dissolved solids already in it potentially messes up the water the salt mix is designed to achieve. Your answer sounds consistent with this view.
Hence, I conclude I should just mix the Instant Ocean with the RO/DI water for water changes, and monitor the tank's alkalinity over time, adjusting as necessary.
For evaporation top-up, the B-ionic person said straight RO/DI water is appropriate, because I'm replacing pure water lost by evaporation with pure RO/DI water. He said the buffering capacity in the tank pretty much instantly adjusts the pH of the pure replacement water to that of the tank.
Have I got all this right?
Tom
Instant Ocean's response:
That is exactly right. It is impossible to formulate a sea salt that would bring tap water to natural seawater levels of all ions so any good sea salt should be formulated assuming it will be dissolved in purified water. The alkalinity (buffer) level of IO is already slightly above NSW when first dissolved.
<Thank you for this... There are "special cases", the largest examples I can think of involve a desire to "over-supply biomineral and alkaline reserve for culture... boosted growth, use of carbon dioxide infusion, intense lighting, high biomass/concentration... that one might want to modify new water by "buffering" processed tap water, for use by itself... or after mixing synthetic salt mix if for change-outs... Antoine? Bob Fenner> 

RO/DI water 2/8/05
Hello again, I really did try to answer my question with Google search, but couldn't find a concise answer (hope there is one).
<That's what we're here for!>
Background: We just got RO/DI system. Output goes into a Rubbermaid trash can. There's a heater and small powerhead in that can. Periodically, water is taken from this first can and placed into a second Rubbermaid can. Salt is added. There's also a heater and small powerhead in this second can. After a while, specific gravity is tested and additional RO/DI water added to get the right level (I try to add extra salt initially). We've been using the salt water (at least 24 hour aged) for water changes. We've been using the RO/DI water straight out of the can for top-ups. I've learned that I should be buffering the RO/DI water (but don't know how - what do use). 
<Buffering RO/DI water is not the only way to add alkalinity, but it is a convenient and safe way to do so. I is important to note that ultimately, Calcium and Buffers should be added in a balanced fashion.>
Question: Given my approach described above, what would be the simplest way to buffer the RO/DI water? If I do this buffering, do I need to change my procedures for mixing and using salt water in the second container? If I do this buffering, can I continue to simply take water straight from the first trash can for top-ups. Thanks, Tom 
<There are too many solutions to list! Each way has it's upside and downside. Here are a few of the most popular: 
Kalkwasser: (Calcium Hydroxide or Calcium Oxide powder) These products are sold as "Kalkwasser" in pet stores, pickling lime in the grocery store and quick lime at the garden center. A couple of teaspoons per gallon are dissolved in the top off water and allowed to settle. Only the clear water on top should be added to the tank. Kalkwasser adds a perfect balance of Calcium and alkalinity (buffer). Kalk is fairly cheap and easy to use, but the solution is fairly caustic (watch your eyes!).
Two Part additives: (Products like B-Ionic, Kent CB, Twolittlefishies C-Balance). These products come in two parts. One supplies Calcium and one supplies Alkalinity. They also contain other trace elements. These products are added directly to the aquarium. They are expensive, but easy to use, and you would use plain RO/DI for your top-off.
Dry Ca/Alk supplements: Tropic Marin Bio-Calcium is the only one I am familiar with. These products contain both calcium salts and bicarbonate salts in a dry form. The powder is sprinkled directly onto the surface of the aquarium water. The powder can irritate corals if it falls on them un-dissolved. These products work well, are moderately priced and easy to use. The powder must be kept very dry or it will solidify.
You can also use separate products for calcium additions and alkalinity additions (each dissolved in some RO/DI water), but balancing them may be more difficult. Hope this helps! AdamC.>

Calcium Query?
Hi guys,
My tank is running beautifully, but I have a question about calcium. 
Stats:
40 gallon
Temp: 78
pH: 8.5
KH: 8dKH
Gravity: 1.024
Ammonia: 0 mg/L
Nitrite: 0 mg/L
Nitrate: 5mg/L
Phosphate: 0.25 mg/L
Cu: 0 mg/L
Ca: 300 mg/L
My tank is almost 6 months old (Day 178).  I have 40lbs of Live Rock, clownfish, 3 PJ cardinals, 1 Coris wrasse, dwarf lionfish, 2 cleaner shrimp, xenia, moon coral, red mushroom, 2 feather dusters and some hermits and snails.  I mix my saltwater for at least 24 hours with aeration and heater. I use Kent Sea Salt and Kent OsmoPrep with RO water. I was originally (3 months ago) using RO water and Kent sea salt then realized that I should be using some supplements to raise my calcium levels, which were 320 mg/L at the time.  I was told by my LFS that the OsmoPrep would raise my calcium, so I have started to add to with every water change (10% every 10 days or so). I have done several water changes with the OsmoPrep and my calcium levels are still dropping slowly, almost 10 mg/L a month.  My question is, Should I be using a calcium supplement as well as the OsmoPrep? Or should I be using another supplement rather than OsmoPrep that will raise my calcium and the trace elements I need to use RO water?  Thanks guys, Troy 
<Troy, Kent Marine does instruct the user of Osmo Prep to add Kalkwasser or a liquid supplement for reef aquariums, so obviously the calcium present in the product is not enough for reef systems. James (Salty Dog)>

R/O water treatment part2 2/22/05
One follow-up question: If I use B-Ionic, is there any reason not to use it to treat the ro/di water in the Brute, before that water is used to make synthetic seawater or to top-up the tank? Thanks, Tom
<B-Ionic and similar two part additives are shipped as two parts because mixing them will result in a useless insoluble precipitate. For this reason, they must be added separately (I even suggest several hours apart), and cannot be mixed in make up water. Also, you could add one or the other part to your make up water, but IMO, this would be complicating a very simple process. Hope this helps. AdamC.>

- RO/DI Aeration & Low pH -
Hi Crew. 
<Hi.> 
Hope everyone is doing well. 
<So far, so good... thanks for asking.> 
If you could spare a moment, I have a quick (and very basic) question. 
<Whoops... time's up. Kidding.> 
Can you clarify what is meant by aerating ro/di water. 
<Reverse Osmosis and De-Ionization - a filtration system applied to tap water.> 
I have my top-off/water change water in 5 gallon buckets. I have 1 or 2 airstones placed inside the bucket. I let this sit, with a loose cover, for about 12 hours before I buffer, then let that aerate (with the airstones) for at least 6 hours before I use for top off or saltwater mix... is an airstone or two enough movement or should I be using a small pump? 
<This is fine.> 
I do have slightly low pH in my 55g reef tank...ranges from 8.01 to maybe 8.12 on its own. I add Kalk nightly (but not consistently) by Anthony Calfo's method of 1/16 tsp added slowly... I usually add at least 4-6 cups of this and it barely reaches 8.28. I'm starting to wonder if maybe I'm just not aerating the ro/di top-off water enough? 
<Doubt that aeration or lack of it is your actual problem here... would test your RO/DI water to make certain... but after addition of buffers and salt, pH should be in an acceptable range. Would look for causes in your system... perhaps overstocked, needs a gravel cleaning, perhaps you just need to open a window and let some fresh air in the house - is the time of year when homes are closed up tight. Could be any of those or all of the above or something else; many possible reasons... suggest you spend some time going through our FAQ's on pH as this is not an uncommon problem.>
Thanks for a wonderful site! Any comments or thoughts would be appreciated.
Jan
<Cheers, J -- >

Buffering RO/DI water - Anthony's Response on the Matter
There is much, perhaps, to say here... and the matter is at least a little more of an issue with a higher/faster demand for Calcium/Alk in aquariums with heavily calcifying organisms.
To try to clarify, lets compare the examples of mixing sea salt with three different qualities of water: demineralized (pure RO/DI of near zero total hardness)... medium hard water which includes a concentration of 100 ppm calcium among total hardness... and very hard water (as many folks have around the country) of say 250ppm of calcium among total hardness.
If your brand of sea salt mixes up at 350ppm of Ca in demineralized water... what do you think it will mix up in the medium hard water that includes an extra concentration of 100ppm Ca? And what do you think it will mix up in the hard water of an additional 250ppm of Ca?
Sea salt mfr.s cannot know exactly what the mineral content of your water is... it runs the gamut among users. From naturally soft, medium and hard (or very hard waters) to the different qualities of demineralized water (quite variable among RO units of various membrane ages/qualities)
It is up to us as aquarists to test our source water and adjust it as needed in concert with each sea salt (they range among brand re: Ca at mixing from anywhere roughly between 250ppm for cheapo salts to 450ppm for premium salts). And of course, the issue of Alkalinity and other/lesser minerals/elements in your sea salt and/or source water is the same.
Thus... to expect a sea salt to magically know your mineral hardness/composition(s) and expect it to adjust is... well :p
Bottom line IMO - not all sea salts (quite the contrary) are formulated for pure demineralized water. Don't just take my word for it though... or the mfg claims for that matter... test the brands yourself and see how low they mix up (as if the high number of e-mails we get on message boards re: flat readings aren't good perspective).
If you do not buffer average salt mixes up at least a little to the presumed average hardness of the mfg... then you WILL have the common problems that so many aquarists do with low or flat Calcium, Alkalinity, etc. Most aquarists do not (!) use RO/DI water... and most sea salts are not (!) formulated for this group.
As for aerating... you will notice/see that freshly made RO water is high in carbonic acid. Rather than allow it to chew up buffers/Alk in your new seawater or your system water... you can simply aerate (off-gas as CO2) this acid and raise the (temporary) pH before buffering or salting.
To the best of my knowledge, the above beliefs are matters of "science". That is to say, scientific realities (verifiable) and not just speculation.
If I'm mistaken here... somebody please let me know!
Anthony 

Deionized water question 5/23/05
I set up a tap water filtration systems for water changes for my 125 FOWLR setup...I use a 5 micron particle filter inline with a 1 micron ceramic ( reusable cleanable) filter in series with a De-ionizing cartridge from Pentek...The water it produces is around 0.2 microSiemens at a very slow rate of flow...Is this too pure, and if so what can be done? I have no nuisance algae, but a lot of good coralline growth...thank you. John Gugliuzza
<If you are using DI, your target is 100% pure water, so "too pure" is not possible. Major components like calcium and alkalinity may have to be supplemented, but all of the trace elements that your animals need should be present in sufficient quantity in good quality salt mix. Regular partial water changes will ensure that these elements remain at acceptable levels in your tank. Best Regards. AdamC.> 

A Little Confused...Still - 06/14/05
Thanks for answering ALL my questions.............just a few more.
<<Did you think I wouldn't <G>?>>
If I do switch to using RO water should I gradually do that with my routine water changes and topping off water?
<<This will work fine, yes.>>
I should let the RO water sit for a few days before I use it right?
<<My suggestion would be, as a minimum, aerate for 24 hrs. and then add buffer and mix/let stand for a couple hours before use as top-off...if adding salt mix (after adding/mixing buffer)...aerate and/or mix with a pump/powerhead for another 24 hrs. before use.  If you have the space/forethought, it's best to mix your saltwater and let it "age" for a few days before use.>>
If I use RO water what buffers do I need to add?
<<Can be done with simple sodium bicarbonate (baking soda), though I prefer to mix it (2 to 1) with a manufactured buffer for the benefit of the carbonate and borate salts of the latter.>>
Are you talking about a pH buffer?....what else?
<<pH and alkalinity, yes.>>
And please recommend some brand names that you trust.
<<I'm quite fond of the Seachem buffers (Marine or Reef...either will do) for quality and price.>>
Ok.....that's it for now  :)
<<We'll be here if you need us <G>, Eric R.

Alkalinity
Quick question?
 <<Sure...>> 
It seems I have to add about 1 teaspoon of baking soda or SuperBuffer to my top off water every day to keep my alkalinity around 10 to 12. 
<<By any chance is your top-off RO/DI water? This is pretty typical if so... RO/DI is demineralized.>> 
Is that o.k. or am I adding to much to the system. 
<<Probably fine... do be careful about bringing up the alkalinity too high. I wouldn't go over 12.>> 
I have been doing daily testing and it has never gone over 12. 
<<There you go then.>> 
Thanks
<<Cheers, J -- >>

RO/DI
<Hi Henry>>
I have been using RO water, aerating, adding buffer (if using the water for top-off), aerating again, adding salt and aerating before putting it in the tank. Now I have an RO unit with a DI stage and wonder if there's anything I should do differently.
<<No. I can't tell from the above but I'm sure you aren't using IO in your top off, right? Just buffered and aerated RO/DI water? Good.>>
I have read opinions in the WetWebFotos forums that DI water can leach electrolytes from any organics it contacts and that it is also too pure to add directly to an aquarium without some remineralization and replacement of stripped electrolytes.
<<Yes, this water is essentially totally pure, so it can hold LOTS of stuff in solution, so it pulls those elements from wherever they will come from until everything reaches equal saturation. So, if you make a 50% water change this would actually lower the needed elements in your tank to the mean or mid-point between the old water and new. If your pH is 8.3 in your tank and you add 50% pH 7 top off water, your tank will read at the mid-point between 8.3 and 7. Short answer? Aerate and buffer your top off to 8.3 pH.>>
Other than a buffer, like Kent SupercKH, what other chemicals would need to be added to DI water meant to be used as top-off water?
<<Nothing unless you test for various other elements like magnesium, which can be low in salt mixes. I add a balanced buffer, that's it.>>
Would you add the same chemicals if the water were meant to be mixed with salt for a water change? I suppose the salt mix already has some of the missing parts.
<<I test my change water for pH, magnesium and calcium, just because all the salt mixes and the water they are mixed with are different.
The results are fairly consistent, but it never hurts to check for the majors; pH, carbonate, calcium and magnesium.>> 
Thanks, Henry
<<You're welcome Henry, let me know if you need any more information, Craig>>

Kalkwasser and buffered RO/DI water
In your well experienced and educated opinions would it be OK to use my RO/DI water in my trash can that I have buffered to 8.4 to make up my daily dose of Kalkwasser slurry that I add at night to raise my pH?
<I would be concerned that the buffering compounds may react with and precipitate out the calcium from the Kalkwasser.>
Or would it be best to use non-buffered straight RO/DI water for the slurry?
<That is what I use, aerated though to remove the carbon dioxide which definitely reacts with Kalkwasser.>
I don't want to have to empty my buffered water and start with new but if I must I guess that's what will have to be done.
<I would use it for a water change. It never hurts and you might as well use the water.>
By the way my clam is still burping well!
<Is this a spawning event? Do take pictures if you can.>
Thanks, Jeff
<You are welcome. -Steven Pro>

Got the calcium scale blues
To the crew,
Great job and thanks for all the help. All of you deserve a big hand for all the time you spend helping others.
<Thank you kindly!>
My question is regarding a white film that covers the inside of my mixing container, heater and, power head between water changes. I use IO salt, RO water (pH 6.8). First, I aerate the RO water then add the salt. After 12-24 hours I test the water for salinity and pH and adjust as necessary. I use Seachem Marine Buffer most of the time since the pH is usually only around 8.0. Once everything is settled, I add a cup or two of tank water and let it age with the heater on and the Hagen 802 power head providing circulation for about a week. After about 24 hours it starts to form a white film that eventually covers everything. If I clean the film off the container and such (has a gritty feel) it turns the water white and eventually just re-coats everything again.
<I am guessing you have added too much buffer and caused a precipitation of calcium carbonate by raising alkalinity with the pH.>
If I get to near the bottom where the film is heaviest, it flakes off and tends to clog my power head intake. Am I doing something wrong in the way I am mixing the salt?
<Just a bit too much buffer. This sounds much like my protocol for mixing saltwater, except for the introduction of old tank water. For a frame of reference, I use about 1/2 teaspoon each of Reef Builder and Marine Buffer per 5 gallons of water.>
I have seen this question posted on WWM chat forum, but no one has provided a clear answer. One response was to add magnesium, would this help?
<Not likely, but maybe worth testing. Magnesium should be three times the calcium level.>
I am struggling with my calcium levels and wondering if this has something to do with my low levels.
<Yes, because all your new saltwater's calcium is laying in the bottom of the mixing vat.>
I just tested my water and my calcium is 225, pH 8.2 and alk 5.2 mg/L
<Yep, your alkalinity is too high.>
this is after a 32-gallon water change early this morning (my tank is around 100 gallons total). I forgot to test calcium levels before I made the water change, but the mixed salt tested over 500 for calcium a week ago. Any ideas?
<Do take a look at Anthony's fine article here http://www.wetwebmedia.com/calcalkmar.htm -Steven Pro>

Re: White Film
I am still a little confused. I test the water after I have added the salt and everything has balanced out, then I add buffer until it tests at 8.3. By doing this am I adding to much buffer?
<I would say too much too quickly. Like I said, if you find yourself adding much more than 1/2 teaspoon per five gallons, you are adding too much. I am guessing you are not waiting long enough between small additions to see the change in pH or perhaps your test kit is inaccurate. Regardless, there is not much else the white flake could be besides calcium carbonate precipitate.>
This is what is causing my calcium to precipitate out?
<Yes, my best guess. -Steven Pro>

Re: Kalkwasser and buffered RO/DI water
Hello, I'm hoping to be able to travel and dive the reefs as much as y'all do someday but until then I'll keep searching your brains for info.
<Hi Jeff, go for it, although it could be a long search...>
I searched your site for the feeding of Sun coral polyps but can't say as I found what I am looking for though. When you say to feed them with finely shredded krill or Mysid or other types of fare, how finely shredded exactly do you mean? 
<It means finely shredded *krill*, *and* Mysid shrimp. Does that read better? You shred the krill. The Mysids are can be blended slightly, but they are already much smaller than krill.>
Does this mean chopping the already minute Mysid (which is what I'll be trying to use) in a stick type blender until you can't discern the liquid from the shrimp or do you mean to actually shred by hand or cut with a knife or similar into much smaller pieces? I tried puréeing a mixture of Tetra flake food mixed with Reef Plus by Seachem with my stick blender and then squirting gently at the open polyps but I think the mixture may be too fine to do any good. It comes out the consistency of water with no noticeable chunks for the polyps to grab hold of. I also tried this with frozen Mysis shrimp but think again the mixture is too fine to do the polyps any good. I just acquired three pieces of the Sun coral and want to do what I can to make sure they get fed well.
<Some corals will like that fine watery food and others with more substance, you will get a little of both with judicious blending.>
Also, I think someone wrote in last week about their pH jumping up about .2 when they add Marine buffer but it then falls right back down by as much within a few hours. I lost your answer to that question as to what may be going on but can't find it again. I am having the same problem and don't know what to do to get my pH up and keep it up.
<Test carbonate/alkalinity, calcium and magnesium. Low carbonates/alkalinity can allow pH to drop as can low magnesium. High calcium could depress alkalinity and thus pH. You need to test your parameters.> 
I have drilled a hole through my window and run air line to a CAP 1200 in my 60 gallon acrylic tank I use as a sump and also the same air line is going to my venturi for my protein skimmer trying to stay away from any CO2 that may be in the house and trying to aerate the tank as much as I can. Should I add another air line to another powerhead in the sump? How much magnesium and strontium is too much to keep the pH in check or can you put too much in? How fast does it deplete in a system? Please, any info would be appreciated. Thanks again, Jeff
<Do not add supplements indiscriminately, test for each and add only the recommended dose to raise them to the desired level. My bet is it has nothing to do with how tight your house is and CO2, except at night when pH drops in most tanks. Look at the WetWebMedia sponsors, they have the correct test kits. Craig>

RO/DI Use
I am currently resetting up my 125 gallon tank. I am going to be setting it up as a FOWLR tank. I have a 125 main tank, 55 gallon sump tank, and a 38 High refugium sharing the same sump. I am looking to do this right this time from the start. I have never used RO/DI before and would like to take the plunge.
<I highly recommend all marine tanks use purified water. You will save time and money over tap water by not having to battle nuisance algae problems.>
The tap water in my area is hard and worked for my cichlids, but I don't trust it for a reef or salt setup. My confusion comes when it comes to adding the RO water. I have seen on the FAQ's two opinions. One saying its ok to plumb the RO directly into the tank for auto top offs and other opinions saying its not the best thing to do.
<They are both right. I have seen people use their RO water straight out of it for automatic top offs, but it is not the best option. Taking RO water, storing it for a day, aerating it, and perhaps using it with Kalkwasser is the best.>
Can you help clear this up?
<See above. Hopefully you will understand my explanation.>
I don't wanna make a mistake before I even restart this thing. What options do I have here? Any help clearing this up would be awesome.
Thanks, Tim Turner of Reading, PA
<You are welcome. -Steven Pro>

Buffering Top Off Water
I buffer my top off water after aerating for a day. If I test for KH/Alkalinity, what should my results be before I use the top off water?
<Ugh, what?>
Should I be getting these results immediately after adding the buffer?
<I would wait until the next day. You are looking for trends here, not immediate changes.>
I don't want to use too much. I am using Seachem Reef Builder.
<I would add the same amount every other day, testing on the odd days for one week. Then look back at your records and note the trend. You will then know if you must adjust up or down. Repeat this procedure for a few weeks until you get a feel for your tank's needs. Then just double check every couple of months as things grow, you add new corals, etc. your tank's demands will change.>
Thanks
<You are welcome. -Steven Pro>

Dechlor With R/O?
Hey guys, seems I read your site and pop in a question daily! Always tons of reading to do here.
<Ahh- but what a cool way to spend the evening, huh? Scott F. here today>
I always used SeaChem's "Prime" in my tap water before I purchased my Kent 3 stage R/O (24g per day model, TGF or something like that). Can I toss the Prime now, or should I still use it? Thanks again.....
<A good R/O unit should be able to remove chlorine and other impurities from tapwater...so I'd save the money for other things, like those cool ceramic signs that say "No Fishing", or the "Bubbling Action Skeleton"...Seriously- I don't use these products with RO/DI systems. Hope this helps! Regards, Scott F.>

Buffering
Hey gang, just picked up my Kent 3 stage r/o 24g/D (glad I can still get them wholesale, didn't realize what a deal $200 Canadian is till I looked around), can't wait to see an end to this flipping hair algae.  When I was using tap water (ph 7.6 range) in my 130g FOWLR tank, in my top off water I would use a half tablespoon of SeaBuffer per 5 g, I don't test ph and alk, as I am always in the 8.2 range with my tap and salt mix (IO, Kent, Tropic Marin, whichever the trans shipper has), alls well with fish and coralline on my 200-220 pounds of live rock, now with this r/o I know it knocks all levels down and I need to change my lazy ways, how much SeaBuffer should I add to this water?
<Testing will confirm how much you need. Do please see the FAQ's regarding mixing new seawater suing purified water.>
Is it now needed along with my salt mix, or will salt buffer to the 8.2 usually even with r/o (ph ?)?, is there a usual amount of SeaBuffer to add to each 5g of r/o for top off (no salt), or do I really need to test as there is such a great many variables? No corals and the likes guys, and ol' riot is lazy, but I do follow oh gods of fishland here at WWM, so tell me what I gotta do, one last thing, this PSI rating (65) for the unit, who knows what the PSI of my tap is, does that effect the quality of the water, or just how long it takes to make?
<How long it takes.>
I have the unit sitting inside a laundry tub just below the tap, it is to run for 12 hours or so before use, and so far I am getting a good flow out of the waste tube (might just have that flow into my washing machine so Anthony doesn't think it too much of a waste ;) , and little drops from the good tube, sound normal?
<It should produce about 1 gallon per 4 gallon of waste water. You can measure both with a cup to see.>
thanks for your time as always guys, have a great day!......riot....
<In the future, please use capitalization and spacing when appropriate. We archive all the Q&A's and it is best for other readers if these are in proper English. Your email program should come with a spell checker to make things easier for you. -Steven Pro> <<Yes, this would definitely be appreciated! Barb-->>

Macroalgae and Water Pre-Treatment
Good evening!
<Hello! Scott F. here tonight>
Have just 2 quick (I think!) questions for you this time around.  I recently emailed you regarding changing my "nitrate factory" (sump with bioballs) over to a macroalgae filter, you recommended Chaetomorpha or Ulva vs. Caulerpa. Problem is, I have only found mention of the names of these macroalgae; never any pictures (for identification) or locations where I might purchase them.
<Chaetomorpha is also called "Spaghetti Macroalgae".  It really does look like spaghetti or a kitchen scrub pad! A good commercial source of this algae is Inland Aquatics. Ulva can be purchased from Indo Pacific Sea Farms. There are other commercial sources for these and other macroalgae; it will take a bit of searching. Alternatively, you may want to post an inquiry on WetWebMedia.com's chat forum; in all likelihood, there are other hobbyists out there who have these macroalgae available for sale/trade.>
I searched the site for several hours this week.........(It's a guy thing ya know, never ask for directions!!  Well, I'm convinced........I'm lost!) Any help would be greatly appreciated.
<You are right- there is not a tremendous amount of hobbyist-related stuff on the internet regarding this particular species. Much of the husbandry information that you'll find on this macroalgae is from fellow hobbyists, so do use the chat forum on our site or more information.>
Also, in scanning through all the FAQ's, I caught something about watching your pH, and alkalinity if you use "raw" R/O water for tank top offs.  Can you point me to more information as to what I should be adding to my R/O water before adding to my tanks?
<First, you should always aerate the water before using it; to help drive off the carbonic acid that's usually present in highly purified water. Second, you may want to use an aquarium alkalinity buffer product to help "reconstitute" the water. More on this topic is available on the wetwebmedia.com site, and a further discussion of source water and its treatment is available in Anthony Calfo's "Book of Coral Propagation".>
I didn't realize this was a problem, yet probably explains my low PH.
<R/O water tends to be very unstable, acidic, and have no hardness, so aerating and buffering the water before using it is a necessary step when using RO water, IMO>
Thanks and Happy Holidays!! Doug Edwardsville, IL
<And thanks to you, Doug- Good luck in your efforts! Regards, Scott F>

RO/DI Questions
Hi guys,
I am a few days from purchasing the Typhoon 3 RO/DI from http://www.airwaterice.com/Typhoon%20lll.htm, if you know anything about this model (positive or negative), I would appreciate your input.  
<I have no first hand experience nor know anyone with this brand.>
I've read that after processing the water through the RO/DI you have to use some sort of supplement to replenish certain essentials that are removed by the RO/DI process.
<Correct. Best to read through the articles and FAQ files on treating RO or DI water. My protocol (briefly) is to aerate, heat, mix salt, test pH, alkalinity, and calcium, adjust with additives, and use.>
Can you please point me to a vendor where I can find these additives?
<Just about any good buffer will work.>
Also, any recommendations on a brand name for the additive is appreciated.
<I use Seachem's Marine Buffer and Reef Builder.>
Thanks, Adam
<You are welcome. -Steven Pro>

Distilled water buffer, loose corals
Can you recommend an appropriate buffering agent to use with the distilled water?  I started using tap water, which helped with the acidosis, but I checked my carbonate hardness and it is now 50 ppm and my general hardness is up to 100 ppm.  This is a little higher than I would have liked.  Guess I'll just keep using more distilled water and try to maintain with additional tap water.  I just thought if I am going to add anything, it might as well be minerals that the discus can utilize.
<I would use baking soda, sodium bicarbonate, "Arm and Hammer", unless there is/was other types of life that require other mineral content>
Can you recommend anything to keep my button coral in their place?  My turbo snails keep knocking them off of their rock.  
<A bit of epoxy... these are sold in the trade for this purpose. Bob Fenner>
Thanks, you guys are great

One more RO/DI question
Hi again,
<Hello!>
I was wondering what the best procedure would be for introducing RO/DI water to an established aquarium.  Should I just begin using it for top off and regular water changes, with no changes to my usual routine; or, should I begin with one or more, larger than normal water changes?
<Makes little/no difference. Test the pH and make it match your aquarium and of course...match the temp to that of the aquarium>
As per my last email, I have found 'RO Right' and 'Osmo Prep Marine' (both by Kent), are these types of additives necessary? recommended?
<Test your pH to see if it matches your tank. If not buffer it up using baking soda or other buffer fluid/powder. I am not familiar with RO Right but if it's a buffer agent (and it should state that on the label) then it will work as well as anything else>
Thanks again,
<You're more than welcome! David Dowless>
Adam

- RO Questions -
Hi guys, Bryan here.
<Hi, Bryan, JasonC on this end...>1
Have some questions regarding water makeup with RO. <OK.> Read thru F&Q's and would like some help clarifying some things.  OK here goes.  Make up water to add to tank:  I take my RO water and aerate and heat for a day to drive off CO2 and increase dissolved O2. (this next order is where I'm a little confused) Then add my salt mix (Tropic Marin) aerate for a day.  Test for salinity, pH, and ALK, add buffer as needed from the test results. Sound OK? <I would add buffers at this point, before you add the expensive salt. RO water is depleted of minerals and will take them up like a sponge, potentially leaving you with a lower than desired pH. Best to add either baking soda or a commercial buffer like the Seachem product.>
Evaporation top-off:  Take RO water, aerate and heat for a day. This is where I'm a little unsure.  Test the water parameters and buffer as according? <I'm not sure you need to heat the top off, unless you add it in bulk quantities.> Set pH and Buffer according to main tank display, right? <Ideally, yes.> Last thing to help me clarify.  In the display tank I'll use ESV 2 part B-Ionic for ALK and calcium.  for top off and make up water I'll probably use SeaChem reef builder.  Do using these 2 different buffers in the water have any adverse affects? <No. The two part additive is a 'system' so that the buffers compliment the calcium additive. The buffering in your top-off is really only making sure the RO doesn't lower the pH of the tank.> Ok last thing for real.  IYO who or what company has the best all around supplements/additives, Mg, Br, Iodide etc... (just wondering, only using if test for and find a need) <I don't have any particular preference, but I do try to stay away from Kent and Mark Weiss products.>
Thanks for your help Bryan.
<Cheers, J -- >

- RO Questions -
Jason, Bryan again, thanks for quick response and great info.  <My pleasure.> You helped clarify things for me about RO water treatment.  I was a little confused about the order of adding buffer and salt.  I had read somewhere to buffer then add salt and then last night read someone from WWM was adding salt then buffer.  Got a little confused.  This is probably a silly question. But when buffering the raw RO water, are you shooting
to buffer to the target range for the main display or just adding enough to add some minerals to the water so it doesn't act like a sponge when you add the salt? <The latter, just enough so that the RO doesn't deplete the buffers in the salt.>
Thanks again Bryan
<Cheers, J -- >

Adding a buffering stage to a water purification system
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? << No, it would need to be in solution.  <...Incorrect. RMF> You could add a little Kalkwasser, but I don't know if you could adjust or maintain a certain level with any regularity.  I think you are better off just adding a teaspoon of Kalkwasser every week. >> I know the water is acidic coming from my well and the DI makes it no better << Then your DI and RO stage aren't working.  It should come out neutral. >> 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. << Well if is a solid media it won't just dissolve.  Or at least not at a high rate.  I think powdered Kalkwasser is a simple and easy way to go.  Plus for the most part you want your RO/DI unit working without any additional items that affect the water coming out of it. >>
Thanks
Mike Winston
<Blundell>