New Setups And Calcium - 07/27/05
Having read pages of your dialogue with other reefers, before I ask you anything, I have to thank you for all the stimulating advice/discussion.
<<We're happy to help...>>
I just completed a wooden stand designed to support a 55 gallon tank over a 75 gallon tank.  Over the next month I will set up a refugium in the 55 to gravity feed the 75 main display (80 lbs. of rock) and filter the entire arrangement with a small 20 gallon sump (approximately 24") under the 75.
<<Great!...love the fact you're adding a large (respectively) 'fuge.  Would like to see a larger sump (you'll eventually wish you had the extra space...for media reactors, etc.), but I'm glad you're not doing it the other way around.>>
My original plan was to install a plenum and DSB (6") in the fuge using the method prescribed on your website, and a DSB (5") in the main display with sugar sized aragonite sand.  I am aware of the benefits that can accompany good water circulation, bugs, and detritivore kits in conjunction with a DSB. However, this will be my 1st tank.
<<So glad to see you're doing some research.>>
I have a few questions.  First, is this too much DSB?
<<Not in my opinion.>>
Second, is there anything that I can do while setting up the plenum and DSB in the 'Fuge that might induce the release of more calcium into the system from the aragonite in the substrate?
<<Other than not rinsing the "fines" (these will dissolve more readily) from the sand, no.>>
Or is there any other substance that I could scatter in the DSB substrate that might be naturally dissolved by the normally occurring gasses/processes in the DSB resulting in the release of more calcium?
<<The aragonite sand is already your best option.  Why all this concern with calcium at this stage?  Your tank will have plenty of calcium from the salt mix/aragonite in the system during the cycle period.>>
Third, what method of dosing calcium would you recommend for a beginner with this kind of system?
<<Frequent partial water changes...really!  Until the tank is stocked and you have an idea (through testing) of the demand on your system for calcium, etc., frequent partial water changes will supply what you need.  If your testing determines you need to supplement calcium, the two-part additives work well for small dosages (gets expensive otherwise), else you might consider Kalkwasser or adding a calcium reactor.>>
Thanks again.
<<Regards, Eric R.>>

Sky high calcium problems? 7/7/05
Hi,
I read the FAQ about high calcium but didn't see anyone with as high as I have.  I bought a 40 gal setup from a friend with coral and fish etc. Brought it home, put coral in a diff aquarium I've had setup for years and fish into quarantine tank.  Since the aquarium had been dry for a few hours while in transport I filled with salt water for the inevitable die off, with all living things that i could take out) left out.  Then gave that a week, drained it then refilled, and then tested water after another few days of settling.  The calcium was measured at 1275mg/l !!!!!! I didn't trust the test so i went and bought 2 diff types of ca tests, they told the same measurement!  How is that even possible? < I'm not sure.  But if it is possible it is almost certainly toxic.  I'd doubt those readings.  Are you sure?  Okay I know you are sure lets just fix it. > (two tests used liquid, the other used liquid/powder combo) I didn't add anything but salt water to the aquarium.  < Magnesium is often that high, but not Calcium. > I think my friend majorly overdosed calcium or something and it must be precipitated out into the sand and coming back into the water...other parameters are nitrates 0, ammonia 0, nitrite 0, pH 8.6, Alk low-normal.  Should I continue to do full 40 gallon water changes until it is better? < Well one 80% or 90% water change should fix it overnight. > or is there someway of lowering the Ca concentration? < Replacing water is the only thing to do.  If there is some sort of powdered calcium in the substrate (which is hard to believe) than the entire sand needs to be rinsed clean. > I'm afraid of even putting anything living into this tank until the Ca levels are much lower.  < I agree.  I would also test alkalinity as that is more important than calcium and may lead to ideas regarding this situation. > I'm assuming levels that high would harm anything alive?  Please offer any advice you can.
Thank you for your time, < Change that water and rinse whatever it is that is adding that calcium. >
Amy
<  Blundell  >

- Calcium/Alkalinity Replacement in Top Off Water -
Hi WWM Crew
Great site, the source of all my aqua knowledge, thanks. I have experimented with the various options of dosing calcium - two part calcium/buffer and Kalkwasser. The results seem fine, however I have not tried a calcium reactor due to limited space and funds. My question is - would it be feasible to run CO2 through a air stone in a 60 litre plastic container (in the garage) of suitable freshwater with a substrate of either coral sand or aragonite. <Hmm... I'd say probably better to build a Kalkwasser reactor this way. Calcium reactors are typically used with water fed from the tank. They run continuously so it's not really practical to feed constantly with freshwater.>
My theory being the low ph (due to CO2) would dissolve Ca into the water (as does a Ca reactor). <Well... another item of issue here would be recirculation within the container. If you're set on a calcium reactor, there are many plans on the web for building one from PVC... have seen many designs build for less than $50 in parts. Calcium reactors are actually pretty simple, and you sound motivated enough to build one. Would check on Ozreef.org first.> The result would be calcium rich water ready to be used for top off. The Ph can easily be raised by normal aeration before going into main tank. <Normal aeration will raise the pH only so much - the action behind calcium reactors creates carbonic acid - driving off excess CO2 will only do a modicum of good.>
Would this be good practice or is it to easy to be any good. <Consider your options.>
thanks
Greg
<Cheers, J -- >

Tropic Marin Bio-Calcium
Just a quick question if I may. I haven't discovered much discussion on this site or otherwise on the product "Tropic Marin Bio-Calcium." Have any of you folks used this product and what is your take on it?  
<A very fine product from an exemplary company>
I have a 20 gallon and I'm looking for a decent product to maintain/increase calcium without the least amount of headache (e.g., Kalk would seem to be a far more labor intensive undertaking). From what little I've read, the Bio-Calcium seems like an easy solution. You simply sprinkle it into the tank as directed/needed.
<Mmm, better to sprinkle it into make-up water... Not directly into an up and going system>
Naturally, you'd need a buffer for use as necessary. The only negative I've picked up with respect to the Bio-Calcium is that it tends to increase a tanks salinity over time. Not a big negative, just one to be aware of. 
<This is not a practical matter... folks will hopefully be doing enough water changing...>
In sum, if the above doesn't sound like a good direction to go, what calcium/buffer combo could you suggest for a small tank such as mine. Any particular brand/line? Thanks, I appreciate your observations in advance.
Jon,
Tulsa, OK
<Our various input on this issue is posted, archived on WWM... Bob Fenner>  

Calcium
Good morning crew. Real quick question. I couldn't find a specific answer to my question on the site, but I did learn an awful lot about calcium/alkalinity relationships in the process. I currently supplement the B-Ionic two part solution. However, I wanted to jump start my coralline growth and read that Seachem's Reef Advantage (dry form) was excellent in doing just that. My question, if I wanted to use the Seachem's for a while, would I need to stop using the ESV calcium component, or use less in combination with Seachem's?
Always learning,
Eric
<Utilize your test kits here... dose with the SeaChem product, but check to see that your balance of alkalinity/calcium is not drifting too much. Bob Fenner> 

Understanding Calcium... really understanding it 5/17/05
Hey Anthony,
<howdy!>
Ok, so from my understanding the slurry method is only used to replace daily calcium use. 
<Hmmm... to be clear here: every(!) calcium supplement should only be used to maintain a safe average calcium level in the system.>
Which method would you use to raise calcium levels to the desired levels of 350-450ppm if I'm thinking of adding hard corals in the near future? Nilesh
<I fear you are missing the point overall my friend. Do read here:
http://www.wetwebmedia.com/calcalkmar.htm and explore the links atop the page(s). Best of luck! Anthony>

Dosing Ca
HI
Do you recommend using Reef Builder or Reef Carbonate along with the Reef Advantage? Or will the excess carbonate throw off my other parameters like pH and ALK? 
<You may not have to add anything else. Just check your dKH and try to maintain between 8-12dkh. I would use Reef Builder if needed. James (Salty Dog)> 

Calcium
Hello, 
<Hello Saurav>
Thanks for all your help you guys are great. 
<You're welcome> 
I wrote you guys before because I was having problems with high ALK and high Ca. I changed from Oceanic to Instant Ocean salt and with water changes the level reduced. I am interested now in getting SPS corals. I think I have to start dosing Ca, my number at 420 will reduce I think with more water changes as it has. By the way my ALK is 3.5 meq/L and pH is 8.4. Do you recommend I start dosing Ca? 
<I would maintain 400ppm> 
If so what do you recommend to dose with. I have a 55 gallon tank and Kalkwasser seems to be meant for larger tanks and Ca reactors are pricey. What do you think of Kent Marine Liquid Ca? If you do not think I should start dosing now at what Ca level will it be appropriate time to start dosing? 
<As above> 
Also will SPS corals, as far as lighting goes, will do ok in my tank particularly Acropora and Montipora? I have 265 Watts of power compact lighting. Thanks again! 
<Personally I like SeaChem's Reef Advantage (dry form). It also includes magnesium and strontium, two important elements. It does not have a caustic ph like Kalkwasser and will not deplete alkalinity. As far as keeping monti's and Acroporas or flower pot corals, your lighting would be a bit on borderline, most other corals you could keep. James (Salty Dog)>

Fish Stores in San Francisco
Hi,
<Hello there>
It sounds like you guys are from the bay area. I live in San Francisco. I get most of my livestock and supplies from 6th Ave aquarium but am starting to feel skeptical. Their prices are great but some of their advice resulted in minor catastrophe. What are your favorite stores in the bay area?
<Will have to ask Chuck Rambo re... or Sabrina... or Paul Mansur... they are all from the general area, not me>
I have a SERIOUS problem with Calcium (level is at 720, pH is at 8.0 but I see no precip when adding buffer). I just read that Oceanic salt can cause this so I am off to Nippon to get some water. They use sea water and I have a 12-gal tank. Do you think this is wise? Thanks a bunch!
<... something is off here... first, I would "check the checker"... this test kit/device is likely off... I would be very careful with such a tiny system in terms of matching well-seasoned, pre-mixed water of similar quality...>
Annie
San Francisco
<Bob Fenner>

Calcium problems
Hello crew,
Researching your site has been somewhat of a help, but with my problem there has been no real answer. My tank is four months old and my problem lies with keeping my calcium at or above 350ppm. I have recently been dosing Kalk slowly at night for various reasons; raise calcium, lower, stabilize alkalinity and raise the ph. The alkalinity has stabilized from 14 to 10 and my ph is at 8.2-8.3, but the calcium has lowered from 350 to 300 today. I am aware of various scenarios regarding calcium precipitation, just not 100% on them. I also have a calcium reactor but was not relying on it until my calcium was higher. 
<Mmm, I'd be firing that reactor over now>
My tank inhabitants are only snails, brittle stars and fish, but calcareous algae and the optimum conditions are my first goal before adding more delicate corals. 
Thanks, Dante
<Dante... don't know what else you have "in" the tank substrate, rock wise, but don't wait on hooking up, turning on the reactor... In all likelihood the simple addition of the carbon dioxide alone will solve your low/er calcium issue. Bob Fenner> 

Calcium level at 580
Hi there,
First of all, thank you for your time answering my question. I have a 120 gallon reef tank and it is a relatively young tank(4 months). I started using a combination of Kalkwasser doser (around 1/2-1 teaspoon/day) and Kent liquid calcium (2 caps(10ml) every day) along with Kent ProBuffer dKH(6 caps each day(30ml)) one and a half months ago. Before I used this method, my calcium level is 440 and I never checked it again until now. I was really surprised when my test kit read 580. I don't have any alk test kit that measure the precise amount but I have the ineffective one from red sea marine lab. My alk reading shows high but it didn't give me any precise measurement. I uses pinpoint PH monitor and it shows a steady reading from 8.1-8.3. Please tell me what should I do now, I have lots of mushrooms, zoos, and polyp corals along with several fish. There are no sign of distress from my fishes and corals. My corals are fully open every day. Will this high calcium effect my fish and corals if I keep dosing like this.
<Calcium levels this high are not good. Stop dosing calcium right now and wait for the level to come down to 380-400, then continue dosing at a reduced rate. You will soon find the proper dose to maintain calcium at 380-400.> 
I'm planning to stop using liquid calcium since I read in your website that it's not good for long term use, but how about my Kalk, do I need to stop this as well until my calcium is back to normal level? Please tell me what I should do. and 1 more thing, what's the best PH for keeping xenia and polyp corals. 
<The pH you are maintaining is fine for these corals. I believe the inexpensive calcium test kits have a difficult time accurately measuring the calcium ion we are concerned with. I think the Hach or LaMotte kits are much superior in this regard. 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.>

Something wrong with "articles" web server?
The last couple of days, I have tried to access various articles on the web site (tonight I wanted to read the article on Kalkwasser).  When I click on the link, I get the "header", including the title of the article, but no text.  I tried to access several different articles, and tried from 2 different computers.  Each time, the header appeared but no article.
Could the webmaster look into this?
Thanks!
Ken Baker
<Thank you for this note, reminder... we are unfortunately perennially behind... in getting to actual writing of variously needed content (writing, photography, graphics), but still need to "place" ongoing accumulations of "FAQs"... A pledge to you... if you will write article inserts, to help you sell these to the print and online 'zines. Bob Fenner, one of dozens of volunteers who are the WWM crew.>

Re: something wrong with "articles" web server?
Bob--thanks for the reply.  Just so I understand--you're saying that there are titles for future articles in the listing of available articles, NOT an issue of articles that exist that for some reason have come "un-linked" from their hyperlinks and are lost in cyberspace?
<Yes my friend. Thank you for making this clear>
Thanks for all you and your dedicated team do.  My immediate research has to do with how to best dose calcium without going the ca reactor route--my aquarium is in an open space between kitchen and family room (great for viewing from both sides) but the cabinet underneath is completely full with skimmer, sump, and small chiller.  There is no room for ca reactor and it's not the kind of thing I want on the wood floor next to the stand.  The least unsightly of the bunch is the chiller, so I may be able to move that outside the cabinet if I can find a reactor that will fit in the space that frees up.
Thanks again
Ken
<Ahh, perhaps the next system. The best alternative for the majority of systems, aquarists are "two part" solutions... either home made or store bought... that include in one part, the actual alkaline earth materials (mainly calcium and magnesium... perhaps with a touch of Strontium), the other the alkalinity component (carbonate, bicarbonate/s...) and other material for keeping all in solution... Much more "complete" than Kalkwasser et al., and much safer, easier to use... There is much "difference of opinion" on this topic (even on WWM!) as you will likely see... it is obvious that you are able to discern fact... and make up your own mind. Bob Fenner>

- New PinPoint Calcium Monitor -
Hello guys, have any of you used the new Calcium Monitor from Pinpoint (retails for $249)? 
<This item is very new and unfortunately they don't send me new products for testing so no... I haven't used it.> 
Any ideas on how long the probe will remain accurate (just the replacement probe is $199)? 
<No idea at all, but like any monitor probe, I would suggest that you clean it often. Many probes go south prematurely because folks leave them in one spot for as long as they last. But man, that is an expensive probe. Think of the number of calcium tests you could buy for that... knowing the calcium level from minute to minute seems excessive, perhaps even obsessive/compulsive to me, although I'm sure there are some out these who've already snatched these up. I'm going to stick with my titrations.>
Thanks,  Franz
<Cheers, J -- >

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)>

Specific calcium method
Sat, 05 Feb 2005
Hello,
I would like to start out by saying that you provide an extremely valuable site for information. I have read days and weeks worth of information here and it has been a tremendous help.  I have read a huge amount on calcium but I am looking for (and maybe this is unrealistic) a "this is how you do it" answer for keeping calcium levels stable. I have not really found a step by step answer, in other words if I go with the Kalkwasser, how do I set that up and figure out how much to dose and how often, for example, is that done continuously or a weekly thing etc. if I go with a two part solution what is it, how is that dosed, and how much.
I know that I could probably get some of these answers on the bottles but I don't want to just buy the different things so that I can read the directions.
Is there any advantage with one or the other? If there is some place that I could be directed to I would be more than happy to read all the information but I just can't seem to find the specific info that I am looking for. I tried to ask the LFS owner (all saltwater store) about the Kalkwasser and she said that it was a pain in the behind and that the delivery system is always getting clogged and it is expensive. (my checkbook has already stretched farther than it ever dreamed it could, so at this point I am quite willing to spend the extra money and not skimp now, I want to do it right, and not mess things up just to save a little money, does that make sense?) She sold me the Reef Advantage from Seachem and said that would be fine. I have read that this would be fine to raise it, but not to maintain it, that in the long run that is going to cause more problems (calcium chloride?) and that is not what I want.
I have used it only when my calcium dips below 400 (380). When I do add it, I mix with RO water, dissolve then drip into the stream from the powerhead.
I know that my reef tank is only going to demand more as time goes on, right now I have soft corals, and bubble, hammer and the like, I want to get a clam eventually but LFS said that my calcium would have to be absolutely 425 always, and I don't think that I am ready for a calcium reactor.
I am sorry I am trying to keep this short. Real quick specs here: 75 gallon, 150 lbs live rock, Rena Filstar XP3 canister, a second one was dedicated to RowaPhos for removing phosphates, turned off at the moment, 4 power heads, two that sweep,  New AquaC Remora Pro, awesome, (bought this because I could not get my nitrates down from 50, tetra test, just bought Salifert, trying everything I can to get the nitrates down, now down to 25) PH was constant 8.0 tried for a while to use Seachem Reef Buffer, never moved from 8.0 (got new Corallife Aqualight Pro light, *absolutely awesome*  left glass lids open, PH now around 8.1 to 8.15 (lights, lid made the difference?) Nitrites <.03   Ammonia 0   salinity 1.025   PO4 .03   alk 2.97 (DKH 8.3) still can not understand why there are two listings for alk/dKH on my test sheet (Salifert) this has steadily went down, dKH gone from 11.5 to 8.3 over several months.
Calcium range over several months has been 375-425 most recently hanging around the 410-420 range, doing a mix of Reef Advantage around once a week or a little longer to keep it there. I absolutely, without fail, do a 10% water change weekly with RO water from LFS. I add 2 caps of iodine every Monday, 1 1/2 caps Essential Elements after every water change, Phytoplex  1/2 cap every Tues. & Sat. was using Coral Vital on a regular basis, but then one day it completely freaked out my old skimmer, tank white with bubbles for days, and now I am afraid to use it.
7 fish, yellow tang the biggest of the bunch, two shrimp, 2 crabs, several turbo snails, bumblebee snails and a few other small ones that I don't know the name of, one sand sifting sea star. Feed Formula Two flakes in the morning, frozen Mysis shrimp in the evening, to the fish and the cup coral.
I think that about covers it, I again apologize for the length. I just have two concerns, calcium maintained and nitrates. Also, I have noticed that I usually do a gallon of RO water to top off, since the new light has been up, every other day or so. I would like to do a refugium but I have a whole other set of questions on that, I will save that for
another day. <I will try to answer the two questions you have concerns with.  Maintaining calcium levels with the least hassle would be to use SeaChem's Liquid Calcium.  For economics (money saving) buy the larger bottle.  This product is very good at growing coralline.  I personally do not like the two part mixes since every time I've used them the alkalinity would always go sky high.  Unless you can buy individual bottles of part one and part two, I would stay away from them.  All you need is the liquid and alkalinity buffer.  There is no automatic way of dosing to maintain a certain level.  Every tank is different depending on calcium using animals.  The only sure way is to test every other week and maintain.  Dosing Kalkwasser is cheaper since a bottle of it goes a long way, but like your LFS says, it is a pain in the behind.  As far as nitrates go, maintain the suggested 10% water change weekly and clean your skimmer weekly, very important.  Watch your feeding.  Feed sparingly a little at a time until the fish lose interest.  You may want to put Chemi-Pure in your canister filter.  It will take organics out that a skimmer will not.  I've been using it with excellent results.  James (Salty Dog)>
Thank you, your help is greatly appreciated.
Rhonda

Re: Specific calcium method
Sat, 05 Feb 2005
Thank you for getting back to me so quickly.<Good morning Rhonda, and your welcome.> I may be misunderstanding something here. I see that the Reef Advantage has calcium chloride but I also have the Reef Complete liquid and it has the exact same ingredients, one being powder one being liquid. Or is there a completely different Seachem liquid calcium? Do I need to worry about the chloride over the long haul, and if not is there any advantage with one over the other when it comes to liquid or powder? <The product I'm referring to is called Reef Calcium.  It is in a calcium gluconate (polygluconate) form.  It will not raise your ph where as Kalkwasser, administered to fast, can drastically raise the ph of the system.  The advantage of reef calcium is that there is no hassle i.e. mixing, dosing etc.  I have used Kalkwasser in the past and found that pumps and powerheads have a shortened life.  After six months use, an impeller in a pump was completely covered in a calcium skeleton.  Kalkwasser is the cheapest way to go for that matter.  I guess the choice is yours.  I really don't think chloride based calcium is going to have any detrimental effect in the long haul.  James (Salty Dog)>
Thank you.
Rhonda

Our method of adding calcium - 2/2/05
I absolutely love this site. 
<Awwww. Thanks. We love it too. A valuable resource for information.> 
You are awesome... I currently have a 240 with some softies and some mushrooms. I use Ocean's Blend two- part system for calcium. 
<As good as any I guess> 
Should I do this everyday or watch the levels? 
<Watch the levels. I suspect that since you only have softies in the tank that the calcium level is likely stable> 
Is this even a good way to get good levels of calcium? 
<Well.....my favorite is......ready for it.......a water change! That's right.....a water change....> 
Because I want to setup a 90 gallon that is mainly SPS and clams... Reading through your site a reactor is the way to go. 
<A good consistent source of calcium with less daily fussing over the tank, but the absolute easiest way is to maintain the overall water quality by changing the water regularly. Keep an eye on the levels. As soon as they start to drop you could change the water 10-20 percent. Of course it really depends on how fast and drastic the change is. Sometimes a water change isn't enough> 
But I don't really want to spend the money. 
<Understood. Well, saltwater aquariums is not exactly the cheapest hobby, but a water change might be your best bet, second to Kalkwasser in the freshwater makeup solution> 
Will the two part system be enough for SPS with the addition of eco-systems reef solution? 
<Yes, likely> 
Thanks you so much....
<Hope this helps. Any of the above would/will work. Now, which is the most cost effective and the easiest for you to administer. Also, is the proper application for your needs. If a drastic change is needed then the two part is a good bet or if the levels drop due to lots of coral and clam use. One of the more stable ways and easiest to administer is the reactor. Lastly you can use water changes and Kalkwasser in the makeup water if you like to fuss a little bit more but it is tried and true. I add nothing to make tank but makeup water (daily) and seawater (water change) I have an all SPS and clam tank. Sorry for the long drawn out answer but wanted to clarify. Thanks for being part of it all! ~Paul>

Correcting High calcium, Low Alkalinity 1/22/05
Thanks.... you mentioned a large water change, how large should I go my tank is a 46 gallon...
<one or two 50% water changes in the next 7-10 days to get back to par before adding ESV>
...and it looks like I will get another yikes from you, I have used Oceanic since I started this tank.
<Yikes! Hmm... in the sense that they are able to achieve the much touted "high calcium" levels by... er... cheating on the buffers (flat Alkalinity). That's not necessarily a bad thing. Some people favor this... others struggle with it (ahem). ;)>
What brand do you suggest?
<Tropic Marin is the best quality hands down... and IO is the best value brand sea salt IMO>
I have read horror stories about IO that people have to dose their top off water and there mixing water do bring up the balance to match there tank water.
<In my greenhouse of eight thousand gallons... I'd buy IO in 8K gallon mix pallets. Now that I only have a three thousand gallon fish room, I use less salt. Heehee... to say that I have had a good experience with IO quality and QC over many tens of thousands of gallons of water in the last 10+ years would be an understatement. Its a good salt my friend... they are the industry standard>
So basically then by me dosing just the ESV 2 part mix, will not bring my readings of CA 420ish, pH 8.3, and dKH 10 - 12?
<it will... once you start with the same ratios, however low that might be. But if your ratios are off to begin with (as they are now... skewed by your sea salt)... the liquid going into the aquarium will not make the corrections... it is not omnipotent... just balanced. You have to pay more for the former ;) Anthony> 

Best calcium to dose with? 
I have 3 tanks set up right now, 2 reef of 390 gal and 455 gal as well as the fish only tank that is 96"Lx72"Hx32"w  I have been using Kalk for several years now in these tanks, yet still no coralline algae growth to speak of, in the 2 reef tanks the pH is 8.2-8.4, dKh 13, ca 450, No2 not detectable, No3 <10 Po4 not detectable NH3/NH4 not detectable, pumps are the same size on both tanks 2400gph I have 2 Huge protein skimmers that produces quite a bit but drains into waste line, I have a Kent COM450 RO w/ DI that makes my water, 4 (400wMH) above each tank. I still have a problem with Cyanobacteria every now and then but my HUGE population of blue leg hermit crabs seems to  keep it somewhat at bay. Now the Question.... There is a pet store near me that specializes in salt water that said I may need to change my calcium dosing methods????? he mentioned a 2 part I think called ionic or something like that, was a Part "A" and a "B" both being a liquid... What would your suggestion be to the best calcium to use? BTW most all of my coral (excluding that elusive Xenia) does very well, especially the elephant ear mushroom that I got when it was just about 2" across, now it is about 18"....would appreciate your input.<There are some sea urchins that do gobble up coralline.  Do you have any urchins? James (Salty Dog)>
thanks
Bryan
<<Huh? Please see here re: http://www.wetwebmedia.com/CalciumFAQs.htm
and the Related FAQs in the series (links at top). BobF>>

Calcium and Urchins 1/11/05
No sea urchins in the tank I find them to be quite destructive on the corals.
<this is a common and mistaken reputation of urchins because the wring urchins are usually purchased (rock boring short spine species, pencil urchins, etc.). The best Urchins are Diadema... totally reef-safe, nimble, do not eat much or any corallines, superb algae grazers, etc>
So what in you opinion is the best type of calcium to dose with, excluding calcium reactors...
<common calcium hydroxide... its time-tested and true with more benefits than any other form of calcium. Read more about it in our archives at wetwebmedia.com>
had a bad experience with them once.. do not what to have that again.
<its sounds like you knee-jerk react too easily my friend. Just because you've been given bad advice about urchins and calcium reactors, doesn't mean they are bad themselves. Calcium reactors are the single best and most reliable way to dose calcium and raise alkalinity in reef aquaria>
Bryan
<best regards, Anthony>

Re: Calcium and Urchins 1/12/05 Antoine to JamesG
To help a bit on that question and for your future reference, mate... your urchin guess was a bit of a long shot, Most urchins are quite useful (critical on the reefs for algae control and  useful in aquaria). A few of the mismarketed species are cheap and abused... pencil urchins lean carnivorous (grazing benthic animal matter more than algae), and a few of those short spine black urchins (Echinometra and the like) are rock boring! And yes... graze corallines. But a bevy of others are very useful and reef safe... not the least of which is Diadema for tanks big enough to let one grow out.
Their problem is/was lack of corallines though... and one great, reliable solution is Seachem's liquid calcium (polygluconate). It is... heehee... useless for coral growth IMO, but (!) it is simply outstanding for growing coralline algae rapidly. You have my promise that most aquariums that gets a 3 month dose of this cheap calcium will be swimming in calcareous algae!
FWIW
Anthony :)

My crazy "reef" system (Calcium concern)
Bob (or whoever is answering today)
<A few of us>
Let me describe my current status of a 55g I have set up.  It relies very heavily on plant life (macros)
<Mmm, macrophytes are not "plants", but algae>
in an in tank refug, has two 4' utility fixtures overdriving 2x t-8 bulbs. Plus two 4' utility fixtures behind point forward to light up the in tank refug (an egg crate crammed in there about 3" from the back glass). Back tubes are 4100K
<This temperature/incandescence is too low... should be 5,500 Kelvin minimum>
3300 lumen, top tubes are t-8 6500k and actinic. I have Chaeto, Caulerpa profilera plus some grape and a red grape.  substrate is silica play sand, rocks are silica/lava/quartz type base rocks.
<Am sure you've read admonitions re silicates and aquariums>
I also have an external sump/refug with a DIY filter box with crushed oyster shells as filter media and some red landscape lava rocks at the entrance/exit.  A mag 5 provides ~ 5x water flow between the display and sump/refug.
<Neat, sounds like a good DIY system>
Tank has a yellow tang (1 3/4 years), firefish, two wild caught gobies, watchman gobies, two "Nemos" and anemone (both about 1 year). Corals include button, zoos, yellow and green star types , frogspawn, a green leather, a pinkish/brown star polyps, several green Ricordea, open brain (~ 1.5 years), a purple gorgonian, and a dark green hard coral with small polyps.  All corals are opening nicely with nice polyp extension.  the dark green hard coral has experienced nice growth including several of my accidental frags.
I do no water changes just replace the evaporative water.
<Not indefinitely>
I use straight untreated tap water in all my tanks. but I do use cold water ran for a minute from a faucet used many times daily.
Ph is ~8.4 just before light off and under 7.8 just before lights on.  (aquarium phar***** test kit).
Whew!!!! now for my question.  I added the crushed oyster shells to get my calcium up.  the 55g and my 20l I use for macro algae culture both and 250-300 ppm calcium with the red sea test kit (measures 50ppm steps).  I got a SeaChem (sp)  test kit and then added the crushed oyster shells.  calcium rose over 6 weeks or so to 400ppm in the 55g. And has stayed there for at least 6 months.  But the 20L macro tank with the same percentage of evaporation and same substrate, has remained at under 300ppm Ca.
<The algae are taking up the alkaline earth materials.>
It seems to me that at least some low level of calcium buffering is being provided by the shells.  What do you think?
Bob
<See above. I wouldn't be concerned with the 300 ppm. Calcium if your system's are doing what you want them to. Bob Fenner>

Calcium test kits?
Dear WWM crew,
  Was curious if anyone there had experience with this brand of kit.
According to the dating on the package the reagents are within their shelf life, but when I add the first step with my saltwater I get no color change to blue? << And you are sure you should?  Hmmm, I doubt it has gone bad. >> Any help or a recommendation for a different kit would be much
appreciated! << I don't think you can go wrong with a RedSea test kit. >>
Thanks In Advance
<<  Blundell  >>

Test Kit Discrepancy 12/16/04
Hey folks, I'll cut right to the point (sort of). I have a Lamotte Ca test kit. I have two Salifert Ca test kits. The Lamotte indicates something like >800 ppm. The Salifert shows less than 200 ppm. Now I just realized today, after months of using the Lamotte kit that it measures CaCO3 (calcium carbonate) which isn't the same as just free ion Ca (right?). <Well, I will be totally direct... maybe.  Sort of.  Is your LaMotte test kit a harness kit or calcium kit?  It sounds like it is a harness kit which would measure all hardness metals (Ca and Mg mostly) and give you a result AS IF all of the hardness was from calcium.  I would trust the Salifert, especially since they agree with each other.  It is also possible that one of the reagents is bad.>
Ok. I previously bought a Salifert Ca test kit when I started getting the really high Lamotte kit readings. This (the Salifert) should just measure Ca ion concentration, right? I thought the Salifert was wrong when I started getting readings of 190 ppm over the past couple of weeks. So, I bought another Salifert test kit. I got the same readings as the first Salifert, which is OK and sort of a relief for me to know that at least the kits are accurate with respect to each other. <Salifert test kits are know for good quality, but also for subtle, hard to see color changes.  I can usually see the color change best in bright natural sunlight and often get verification from my wife.>
I started to throw out the Lamotte Kit when I read that it measures CaCO3 not Ca, which would make the readings seem substantially higher, right??? So maybe the Lamotte readings of 800+ are actually OK since it's not just measuring Ca by itself.
<The kit is probably fine, but it is not measuring what you expect it to.>
Is there a formula to determine the amount of Ca (in ppm) from CaCO3 reading or a table to cross reference the readings? Should the CaCO3 be around 900 or so? Is my thinking outta whack? BTW, my alkalinity is 12 dKH (Salifert test). Thanks, Randy <There may be, but you would probably have to measure the Mg and subtract which would probably defeat the purpose.  Best Regards.  AdamC.>

Calcium too high - 12/13/04
Good morning, <Hey>
I'm having a some trouble with my calcium levels in my 10 gall nano tank. I just cant drop it down to 420 ppm. <Where is it at?> I add the maximum recommended dose every day and it still doesn't drop. <Dose of what?> My tank has been running for 1 month and I had it at 420 before but then it went up. What could this be??? <Could be a lot of things. Have you looked through our FAQs on Calcium? See here: http://www.wetwebmedia.com/Calcium.htm and here is a topic that needs understanding http://www.wetwebmedia.com/calcalkmar.htm. Do regular water changes with good quality RO water and a quality salt mix. Try a Halimeda algae as well. This tends to use up a lot of calcium in its growth process. ~Paul>
Thanks for your time

Ca too high?
Hi Crew,
I have been attempting to raise my calcium level for several months but I could not get above about 400 ppm, using my Hagen test kit.  I use a Nilsen reactor to dose Kalkwasser for all makeup water and I have been adding Seachem’s Reef Advantage Calcium occasionally also.  My alkalinity typically remains low as well (~ 3-4 meq/L), so I dose with baking soda and occasionally with Seachem’s buffer.
<< Just raise your alkalinity and don't worry about the calcium. >>
Last night I discovered that my Hagen Ca test kit was empty so I just purchased a SeaTest kit and, to my amazement, it just reported my Ca level to be 570 mg/L!!!  Does this sound possible?  << Absolutely. >> With the low alkalinity (currently 2.5 meq/L) I can understand that Ca could possibly be at an elevated level but 570 mg/L sounds unbelievable high.
<< Not unheard of at all.  I've had tanks with Ca over 1000 mg/L. >>
I had also assumed that my Ca level was low because, although my aquarium has been established for nearly 2 years, I have been unable to grow coralline algae in any significant quantity.  I was just beginning to see some increase coralline growth but then it turned white and began to flake
off. << Usually more of a problem with alkalinity, or maybe even lighting. >>
Here are my tank stats: 180g tank + 50g refugium (DSB + Caulerpa & Gracilaria), Temp=78F, Salinity=1.024, pH=8.1, Ammonia=0, Nitrite=0, Nitrate=2 ppm, PO4=0.02 ppm, about 10 small SPS corals + 5” squamosa clam for Ca demand, several fish.
What do you recommend?  Should I attempt to dose more carbonate or am I in danger of precipitating all my Ca?  Maybe I should dilute my tank water by 50% and re-test (multiplying test results by 2)?  Water change???  What do you think?
<< This is so simple you won't believe it.  Do nothing!  Your tank is fine.  People strive for Ca that high.  Stop adding things and just do nothing for 8 weeks. >>
Thanks for the help!
--Greg
<<  Blundell  >>

Calcium too high?
Hello WWM Crew,
I read your archives for hours looking for a problem similar to mine before writing because I am sure you are extremely busy.  I found some that were close, but not exactly the same so here it goes.  I have tested my calcium ever since the tank was set-up which was May of this year.  Recently (the past month or so) the levels have read about 640ppm.  I wasn't sure if the test kit (SeaTest) had gone bad so I bought another one today (Salifert) and tested the water.  Same results as before, Calcium above 500ppm.  I tested the Alk (Salifert) and test results showed 2.63 meq/L, and the test kit recommend 2.9.  The kicker is that I have not used a calcium supplement (B-Ionic 2 part) for about two months now.  The only supplement being added to the tank is EcoSystem Reef Solution and I emailed those folks and they said it did contain some calcium but, not enough for a tank with LPS/SPS or clams.
The coralline algae is growing like crazy, even on the glass, thermometer, heater, etc.  I have done water changes of about 25 gallons (100 gallon tank) with RO/DI water two or three times and the levels will not go down. << Great, stop trying to lower them. >> I use Instant Ocean salt and I understand that the salt has calcium in it as well, but enough to keep raising calcium levels in the tank?  I have four LPS corals, a couple of softies, 120 lbs live rock, and nine fish (gobies, tang, clowns, Chromis).  Please let me know how I can bring the calcium level back down to an acceptable range. << Here is what you should do.  At least what I would do.  I'd start adding or dosing a buffer solution.  Like one half of the B-Ionic solution.  It will really help to raise your alkalinity, allowing more coral and coralline growth, bringing down your calcium. >> One more question, I recently added the large CPR AquaFuge to my tank and added a Caulerpa algae pack (looks like feather) to the refugium with Kent bio sediment and a few pieces of live rock.  It has been running for a week now and I have left the refugium light on 24/7 because I read that the Caulerpa would not go sexual this way.  Is this true? << It may be true, but I still just leave my lights on at night. >> Mine seems to be going sexual (turning white and gooey) and dying
off.  Are there other algae species you would recommend? << Caulerpa racemosa, the kind that is unfortunately called "grape" Caulerpa. >> It doesn't
seem to be growing for me and I hear it is a relatively hardy species.
Sorry about all of the questions, but after these are answered I will have a little bit better understanding of what is going on in my tank (a never ending battle it seems).  Please let me know if you need anymore details in order to make an accurate assessment.
Thanks For Your Great Website,
Luis Curro    
<<  Blundell  >>

Ca too high? continued
Thanks for the response Blundell!  Earlier today I did dilute a sample of tank water 50% with RO water and repeated the Ca test.  This time the reading was 465 ppm.  So there does appear to be some variation with this test but, in any case, it sounds like either reading should not be cause for concern. << No, no reason to worry at all. >> I did just buy Seachem Reef Calcium since I read on WWM that this has delivered good results at establishing coralline algae.  I guess I will just wait to use it now though.
<< Good idea. >>
Since my Nilsen reactor is connected to my top-off water (via a float switch and a solenoid valve to my RO filter), do you see any problem with leaving this connected as-is? << No that sounds fine. >>  I am assuming this should not overdose my tank with calcium - correct?  Lastly, I have never had a pH reading over 8.1, even with 100% Kalkwasser makeup water.  Does this indicate a root cause I should be trying to identify or should I just continue dosing (or increase dosing) buffer? << Well I don't think you can really over dose buffer.  Okay, you certainly can.  But most people neglect this area and just add too much calcium.  I think you are fine, and if your reactor is adding calcium and buffer it will add them in a balanced portion... which is what you want.  So I think everything is fine. >>
--Greg
<<  Blundell  >>

DSB & Calcium
Hello WWM,
<<Hi there>>
I have two questions the fist being. I have a 90 gallon reef tank that has been set up for 9 months. I have about an inch of live sand as a base. I was wondering since I have quit a bit of live rock and soft corals, is it too late to add a DSB? Everything in the tank is starting to look really good and would not at this point want to mess it up. I'm not sure if moving all that rock with corals attached would cause havoc on them or would it be worth the risk from the long term benefits? Also If I use sugar sand can I pour it over my live sand that is a little more course?
<<Fishkeeping is subjective, so the answers to these things depends on who you ask :P I have had no problems with deep sand beds. Thing is, they DO need to be maintained (water testing needs to be done regularly, so you can foresee any pH etc, problems and remedy them) You don't want your sand bed to become supersaturated with organics without your knowledge. There is plenty of opinion in forums here about DSB's, read on! If you have a sump, you can put your Deep Sand Bed there. That way you will not have to mess up your reef structure: this is beneficial for a few reasons: the ease of installing it, maintaining it, an removing it if you change your mind further down the road. Another idea is if you have enough open space at the front of your tanks rockwork, you can try adding the sand at the front of the tank only, and just letting it drift back in between the rockwork. If you add sugar sand, you will not need as deep a bed, three to four inches should be more than sufficient, and you can stir in gently into your older sand. Once you do add the new sand let it sit, do not disturb it unless it's necessary. It will take a while before the new sand bed becomes a nitrate reducing machine, so be patient. I prefer the idea of putting it into a sump, though. Just seems easier.>>
Second question is about my calcium levels. They seem to be quite high around 550 with Alkalinity at around 3.0 -3.5. I was trying to get coralline to grow I might have over done the Calcium a bit. Even after three water changes using Tropic Marin salt the levels have not come down much. I was using Seachem's Reef Complete & Reef Calcium. But I have not added any of those supplements for over a month?
<<First, you might want to try a different calcium test kit, just to verify your previous results. And take a water sample to your LFS so they can test it also, and compare results with yours. Your alkalinity is too low. Is your pH also low? Is your pH stable? Does your tank have good circulation? All things must balance. Please do some more water changes, to lower your calcium to approx 400-450 max, and use your products to keep your Alk and pH stable, if necessary. And, as always, do so gradually.. Please make sure of your test results before adding anything. You should use good test kits, and you should be as precise as possible when doing them. Keep a written record, and remember that a relatively new set-up such as yours can show normal fluctuations. Just be sure they are accurate ones, so you can react accordingly. Keep on testing :)
-Gwen>>   
Thanks again for your help!
<<Welcome>>

- Time for a Calcium Reactor? -
Hi, I am currently setting up a 120 litre marine fish only aquarium. It will have a sufficient protein skimmer, an external filter, double T8 marine lighting and an external heater. I am using Kent marine salt. Is it essential for me to put regular calcium additives in the water, or worse, buy a calcium reactor. I am worried as I am on a relatively low budget. <For a fish only system, you can likely get away with semi-frequent calcium additions. Cheers, J -- >

Calcium Gluconate 1012/04
Hello, I sincerely appreciate the work you guys are doing.
<Thanks!  We sincerely appreciate that you appreciate it!>
I have a question about calcium gluconate.  I presume it dissociates in saltwater to calcium ions and glucose or some other sugar. <It does dissociate, but I believe that gluconate is metabolized by bacteria.>
If calcium levels are sufficient, could 't you just dose glucose if you are trying to stimulate coralline growth?
<Hmmm... you could, though I am not sure how direct the effect is.  The use of simple organic carbon sources (sugars, methanol, ethanol, gluconate, etc.) may provide some direct energy to corals and coralline algae, but the larger effect may be the bacterial growth that is stimulated.  The increased bacterial growth reduces inorganic nitrogen as well as phosphate.  Since phosphate poisons calcification, reduced phosphate increases calcification.  Some "magic potion" products (think of those with cute little cartoons of the mustache and flipper festooned company owner along side of wild claims in their ads) are thought to work this way.>
(I note Moe and others using organic sources of carbon for denitrification, not for coralline growth <Indeed.  Methanol fed denitrators have been around for along time, and the notion of ethanol (usually vodka or grain EtOH) is being rehashed on the message boards as we speak.  The long term efficacy and safety of these strategies is questionable.  If denitrification is the goal, natural methods like deep sand beds work well.  Even coil denitrators can work very well without the need for organic carbon input.>
perhaps vitamin C or acetic acid would do the same for corallines?) Many thanks!  Charles Matthews MD  <Craig Bingman wrote an excellent article on the use of acetic acid to extend the solubility of Kalkwasser.  He showed the balanced chemical equations for the metabolism of the acetate that proved that the net alkalinity was not different than the use of Kalkwasser alone.  I believe that he also stated (if not demonstrated) the same for gluconate.  FWIW, Vitamin C, or any of its forms (ascorbic acid, etc.) along with any other anti-oxidant is a poor choice since their use can result in significant drops in redox.  Many aquarists have noted a poor response to additions of large amounts of vit C or ascorbic acid.  
The bottom line is that "tricks" like inorganic carbon additions are not necessary when other aspects of system design and husbandry are optimized.  However, their may be a place for conscientious and thoughtful experimentation!  Best Regards!  AdamC.>

Calcium Gluconate follow up 10/14/04
Thanks for your thoughts, Adam!  
<Always a pleasure!>
I'm still unclear about whether the addition of calcium gluconate to seawater differs chemically from adding glucose to seawater, since c.g. will dissociate (ignoring the minor calcium issues? Charles  <I am not 100% sure of this either.  There is no question that the gluconate will be safely broken down.  The net effect on any process is likely to be negligible.  My big concern with this as a source of calcium is the lack of alkalinity.  If you are otherwise maintaining alkalinity and/or wish to add some source of simple organic carbon, then by all means go for it.  Hope this helps.  For the definitive answer, check the chemistry forum at reefcentral. AdamC.>

Re: Add CaCl to water change?
Thanks Steve. <You're welcome. Sorry this follow-up is late.> I have tested the fresh saltwater a couple of days after mixing and get 320ppm Ca @ SG 1.024 with a Salifert test kit. <Odd, it ought to mix up more like 380.> When I do a substantial water change after building Ca in the tank to around 380, it always drops because the fresh saltwater is more dilute in terms of
Ca. <Yes, that would happen if adding 320.>Is there another brand of synthetic salt that is higher in Ca? <IO should be. Perhaps you should contact Marineland at their website and ask their opinion. I recently switched to the new Oceanic brand and have been very satisfied. Many feel that Tropic Marin is the "gold standard." I do run a calcium reactor, but as you know, that is more of an alk generator than a Ca generator. I also buffer the RO/DI water with Super Buffer
before adding salt. It would make life more simple if the synthetic salt had more Ca in it. <adding Seachem Ca would be quick & simple.> What concentration of Cl is too much? <I am not aware of any specific numbers on this.> It looks like I need to add about 240g anhydrous CaCl2 to 200 gallons to raise Ca to 400ppm. Regards, George. <Over time, I think you can keep your Ca up by adding a bit to your change water. You could also try the other two brands I mentioned. Oceanic is also usually priced very competitively and is available at most Petco stores. Do contact Marineland. You could also start a thread on our Chat Forum to see if others are experiencing this problem. Hope this helps. Steve Allen.>

Calcium test kit accuracy 10/03/04
I have read several of the FAQ's on calcium, and still have a question.  I have a 125g that I started Sept. 1.  I added 125lbs of un-cured LR on Sept. 11.  Euro-reef skimmer (in sump), fluidized bed.  A lot of my LR has a white coating on it - like a crust.  
<assuming you have adequate water flow for curing rock (20X+ turnover of the tank?), this may simply be decay from hard curing rock>
My calcium readings are off the chart (>500ppm).  
<this seems very highly unlikely after even a few hours (without precipitating). Much more likely that you are getting a misreading from your test kit. Even new kits can give false readings. Do take a water sample to a friend or the LFS for a test of CA on a different type or brand of test kit>
I read about the possibility of a "snow storm" and it is scaring
the crap out of me.  
<no worries... you would have to be/have been adding obscene amounts of Ca>
I changed 19gallons of water today, using DI water -
<yikes! now that is dangerous. Never, ever use/add raw DI or RO water. Always aerate for 12+ hours then buffer 2+ hours in advance of salting or using for evap water>
calcium is still off the chart.  
<I see... all the more reason after using demineralized water to believe that this is a misreading on your test kit>
I have only added Bi-onics only once. Today I just added the Alkalinity part (part 1) in the hopes of driving the calcium down.
What to do?
<I'm as certain as I can be from here that you have a bogus test reading... test again my friend. Anthony>

Saltwater Mix Deficient in Calcium (9/29/04)
For the last 2 months, I have been doing weekly 40% water changes using Instant Ocean at SG 1.024, which produces a Ca concentration of 320ppm. <I would have expected higher.> Obviously, if I exchange this with water from my tank, which has 380ppm
Ca, the final Ca concentration in the tank will be less than 380ppm at the moment the exchange is completed. In order to get the Ca concentration back up, I have to add Ca in excess of the daily dose that satisfies consumption. I asked this once before and the answer I got was that CaCl2 should not be dosed on a long-term basis. I understand that adding CaCl2 to the tank over a long period can cause problems with excess Cl, but how does that relate to using it to adjust the concentration of Ca in fresh saltwater for exchanges? <CaCl2 not the best way to go here either, for the same reasons.> For instance, if CaCl2 is always added to increase Ca concentration of fresh saltwater from 320ppm to 400ppm, the Cl concentration of the tank will never exceed the concentration in the fresh saltwater, or am I missing something? <But that level in the replacement water will be higher than the desired Cl range for the tank.> If not CaCl2, what is the best way to increase Ca in synthetic salt mixes that produce lower than desired Ca concentrations out of the bucket? Thanks, George. <The high-tech expensive way that people with high-Ca-consuming corals is a calcium reactor to keep the Ca in the tank up. Another option is to just add the Instant Ocean and then check the tank's Ca in a day or so and add a two-part supplement like b-Ionic to achieve and sustain the desired Ca. Probably the simplest thing to do: If using RO or RO/DI or DI water, be sure to buffer before adding the salt. I like Seachem's Reef Buffer or Reef Builder. After the salt is added and the water stabilizes, then bring the Ca up with Seachem's Reef Advantage Calcium or Tropic Marin's Bio-Calcium. BTW, how soon after mixing do you test the Ca? I'd give 24 hours to stabilize before measuring. Hope this helps, Steve Allen.>

Can switching salt cause calcium problems?
I have spent most of my day reading all of the posts re calc/alk to get my head around this.
First some background .. I recently (2 days ago) had to switch from Marine Environment to Instant Ocean (ME no longer being imported to OZ).
Previous ALK was 10 dKH (JBL test kit) and Ca (sera) .. for the past two days my ALK has been 12dkh and calcium 340 (same kits).
Other than the coralline algae the only other obvious calc user in the tank is a Catalaphyllia.
pH is 8 - 8.2
My question is  .. should I be concerned? << Or those levels different from before?  They seem fine to me, and I wouldn't worry. >>
Do I dose with a calcium chloride supplement or do I do a 100l (approx
500L) tank with Natural sea water? << I wouldn't add any straight supplement.  If I did add something I would add a two part solution, but probably wouldn't do that either. >>
I know you must get tired of such questions but I don't know what to do .... the calc chloride supplement will bring up my calc but stuff up my
ionic balance. << Yep, probably wouldn't do it. >>
Sincerely and thankfully
Grant
<<  Blundell  >>