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FAQs on Calcium and Alkalinity in Seawater, Products For

Related Articles: Calcium and Alkalinity Explained by Anthony Calfo, Calcium, Biominerals, Using Kalkwasser, Calcium Reactors, Marine Maintenance, Marine Water Quality, Magnesium in Seawater, Strontium in Seawater, pH, Alkalinity, Marine AlkalinityLive Sand, Marine SubstratesReef Systems, Refugiums

Related FAQs: Ca/Alk 1, Ca/Alk 2, Ca/Alk 3, & FAQs on Calcium & Alkalinity: The Science of Calcium & Alkalinity, Importance, Measure, Sources, Use of AdditivesTroubleshooting/Fixing, & Calcium, & FAQs on Calcium: Rationale/Use, Calcium Measuring/Test Kits, Sources of Calcium, Calcium Supplements, Dosing, Chemical/Physical Interactions, Troubleshooting/Fixing, & Calcium Reactors, pH, Alkalinity, Marine Alkalinity, Marine Alkalinity 2, Marine Alkalinity 3Marine Supplements 1,

Mmm... there are many (strong) opinions re methods, brands... whatever S.O.P. you settle on, do continue testing, pre-mixing and storing ahead of use, making gradual changes...

Dosing vs. calcium reactor/Kalk top off     7/25/16
Hi all
Recently I have had a few issues with my aging aqua medic calcium reactor.
It has served me well but with a few panic Kalk additions because of low alkalinity I had a massive precipitation issue where the excess calcium baked itself to my system pump impeller wrecking it.
Not my finest aquarist hour I assure you. I have seen some advanced systems using dosing pumps for the maintenance of Kalk mg and ca (and it seems to be very precise and would assist me long term I feel).
<... the most appropriate, best available technology per your system, organisms....>
It is as you know a huge cost and I was wondering whether my existing setup is suitable enough or is getting a bit old school and I need to invest?
Btw my stock is large Euphyllias. Caulastrea and blastos plus some leather corals.
<.... the wife used to distribute Knop Products in N. Am. for five years...
I'd go w/ simple A/B additions here. Likely SeaChem's Fusion line>
Thanks muchly
<Pleasure. Bob Fenner>

Calcium/Alk Question, KCl, CaCl2 anomaly 5/18/10
Hey guys,
I've been reading for a little bit a bunch of articles Anthony Calfo wrote on your site in regards to calcium, alkalinity, pH, and magnesium. I've been having issues with my LPS (I have no SPS) abandoning their skeletons and I can't figure out why (ammonium, nitrates, nitrites all at 0ppm, pH at 8.2). Well I suspected it was my calcium the other day so I tested it, it was at 540ppm,
<Too high.>
my Alk was at about 8dkh and my magnesium was well into 1500ppm.
<Also too high.>
I make a DIY 3 part solution, calcium is made from Prestone driveway heat which is calcium chloride based. Also I target feed all my LPS every morning.
<Yeeks, would not use industrial type products for aquarium purposes. They really aren't a good enough grade for such, can contain impurities.>
I have only done two water changes in the last year because my parameters seemed ok so I never thought anything would be an issue. Well, after reading an article by Anthony I've come to the theory that I have an excess of chloride ions because I've done nothing to dilute them over the last year. Could that be a possible reason why all my LPS are ditching their skeletons? Due to stress and an abundance of chloride ions in my water?
<The Prestone product does contain a small amount of potassium chloride and this could have a negative effect on your LPS corals if levels are high enough. Calcium chloride should not be used long term but for "quick fixes" of strayed calcium levels. I believe your two major problems are excessive use of calcium chloride, and two water changes in the last year isn't going to do much in the way of diluting the calcium chloride ions. Your other major problem is lack of water changes. Water parameters alone are not indicative of good water quality. LPS corals are a little more tolerant of water conditions than SPS, but still require good water quality and twice monthly water changes of 10% will dilute impurities and replace many of the trace elements these corals may/will require. Your LPS corals are telling you something and you need to react. As to parameters, you never stated nitrate levels. It would be interesting to know what they are.
James (Salty Dog)>
Re Calcium/Alk Question 5/18/10

Thanks for the reply.
<You're welcome.>
Nitrate levels were at 5 ppm about a month ago so I did a wet skim water change and the next day they were undetectable. I have a great fuge in my basement in a 100g Rubbermaid stock tank.
<Ah, wasn't aware of this, does aid in nutrient removal.>
Your reply is online with what I was theorizing. I will step up the water changes in order to dilute the impurities. Thanks for your help.
<You're welcome. James (Salty Dog)>

Damaged B-Ionic 3/13/10
Dear Crew,
Thanks so much for you tireless efforts! I have an issue with B-Ionic calcium/Alk. supplement that I need your advise for. I purchased the gallon containers of this online recently from Marine Depot and the product arrived with the Alk. part partially solidified (the calcium part was fine). I've read about this occurring occasionally when shipping in colder weather and followed the defrosting instructions perfectly. I left the containers alone for a good 3 days as to not disrupt the defrosting cycle.
Upon diluting with RO water, I noticed that the Alk. part had very large amounts of precipitants in it as compared to the pure milky consistency that it should have had. My corals seemed completely unaffected by the precipitants. Marine Depot promptly sent me a replacement at no charge. My question is this: is it ok to continue to use the Alk. part that solidified in shipping? I would hate to waste 2 gallons of B-ionic if it is still usable. Will this hurt my reef in the long run? I was considering giving it to a friend.
<Angela, I would contact ESV re this query. Mail them at info@esvco.com.>
<You're welcome. James (Salty Dog)>

Supplementing Limestone Flour?   8/14//08 Hello Crew, After Googling my head off, I'm having trouble finding an answer. When searching for calcium carbonate alternatives, I've come across a product called limestone flour. Can this be used, dissolved in water, as a calcium/alkalinity supplement? <Mmmm, nominally, yes... practically? Not likely... just not very soluble> "Chemical" supply companies seem to have better prices on "high purity" ground limestone than dedicated marine suppliers. Would this also help supplement the biominerals deficient in calcium chloride? <Mmmm, no... not really... as in other than calcium and bicarbonate... there is nothing else in Limestone... Where would Magnesium for instance come from?> I Googled limestone flour/ground limestone in conjunction with calcium carbonate supplementation and didn't get a conclusive answer that it's a viable alternative. Would this be approximately the same solution to the Tropic Marin Bio Calcium? <Is similar in principle make-up, but...> My setup includes a 120 sps reef with two 110g basement sumps. The first one is filled with live rock that flows over into a second one (filled with a DSB, some rock, and Chaeto) and back up stairs. Just always looking for a better/less expensive way to add calcium without the investment in a reactor. Thanks as always for your help. Without your site...success would be more of a delayed gratification. Jeff <Would like to make a few statements. The use of finely ground CaCO3 can/could be useful, economical IF you had a large, let's say commercial grow-out system of high biomineral use, along with supplying other needed materials. In practical terms however, for the small volume/need you have, the best (cheapest, simplest, most-reliable) method of supplying alkalinity and biomineral content is some sort of reactor... can be DIY made... I would NOT just supplement (alone) this flour... but it's worth experimenting to prove to yourself the value in using "balanced" means of supplementation. Bob Fenner>

B-Ionic Dosing Pump  12/24/07 Hey guys, So I have a 90 gallon reef tank, full of SPS and LPS to the point where I could not add another coral. I have been struggling with getting the correct Ca and Alk levels I want, and have been through a Kalk reactor and Calcium Reactor and am fed up with trying to get them dialed in correctly. <Mmm, there are automated measure, feeding devices...> After comparing the results I have gotten with B-Ionic 2 part Ca and Alk solution with the Kalk reactor and Calcium Reactor, I would like to go back to using the B-Ionic as it is so easy to use and has given me good results. <Is/are fine product/s> My only question is I have an Aquadoser Quadro which I am planning to use to dose these 2 supplements automatically, but after reading some of the Q and A on this issue I learned that the Ca part of the B-Ionic must be stirred vigourously before it is added in order to ensure saturation. So would it be possible for me to add a small powerhead which pumps inline to the bottom of the Ca bottle to ensure that the Ca never sinks to the bottom, and I get as close to 100% saturation as possible? <Mmm, yes... though I'd rather use an external magnetic stirrer of sorts (take a look on chemistry supply sites on the Net)... as this will be far more appropriate technology, not suffer from "clogging"...> If this is a viable option would I need to leave it on 24/7 or just have a couple of hours a day. <Could be put on, timed or tied in with the doser alone...> Also, since I have 2 other dosing pumps, I was thinking of adding either Magnesium, Phytoplex, Zooplex or Strontium, which 2 would you recommend dosing on a regular basis? <Mmm, none of the above... Am not a fan of dosing Strontium (only needed/used in extremely low concentration), and the other alkaline earth element (Mg) is best used via/after testing for free Ca... in proportion... the "plexes", not needed, advised... as dosed> Also, after reading several other articles on adding Kalk with the B-Ionic it seems unnecessary as you would be throwing off the balance between the supplements, is this correct? Thanks for your input! AJ <... Too much to state re... Calcium Hydroxide only really adds calcium... Do you understand the basic (joke not implied) underlying chemistry/physics here? Apparently not... Do JUST read what is posted on WWM re... OR Baensch's works OR Fossa and Nilsen... so you don't get confused... at one time... and write back re specifics. Bob Fenner>

Calcium/Alkalinity Supplements WWW Team, I know that you normally do not like to endorse products, but I am receiving conflicting advice from 2 LFS that I go to.  I currently use ESV 2 part B-Ionic Calcium Buffer System which was recommended by one of the LFS.  The other store said that this stuff is bad due to increasing phosphates and causing hair algae, even though the package states that it does not increase phosphates.  They recommend using Kent Marine Calcium and Pro Buffer.  I have noticed a little hair algae, but not overwhelming, and I have not tested for phosphates (I know I probably should).  Which LFS is right? Do you recommend one product over the other? Thanks for your help <I can only speak with my personal experience with both of these products. I have used the ESV B-Ionic for several months at a time and have never experienced any elevated phosphate or hair algae because of it. Kent Marine calcium and buffer worked best at raising the calcium and alkalinity levels. Overall, I would purchase the Kent product.> Hope this helps, Graham Stephan

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.>

EVS 2-Part Solution Alk/Cal Hello Crew,  <Hello Steve> A few weeks back a reader of your website asked the crew if you could use just 1 part of the EVS solution. Their situation was that they needed to raise their calcium, a crew member did not know the answer so they diligently emailed EVS and they stated they never received a response from EVS at that point in time. I read your website just about everyday and I never saw a response.  On 04/24/05 I emailed EVS because this is my situation, Cal 470, Alk 7.2, PH 8.2, and I want to raise my Alk, I never received a response, did you guys?  "Dear EVS, When using your 2 part buffer system can you use just 1 of the solutions. Example: my calcium is at 470 and my alkalinity is at 7.2 can I just use part 1 to raise my alkalinity? Also if the situations were reversed and I wanted to just raise my calcium could I just use part 2? Thank you for your time in advance. Thanks Steve" <Not to my knowledge. With customer service like that, I wouldn't be using their products to start with.>  I have purchased this product and I don't know if I can use it in this application. Any good products that you can suggest for just raising just my Alk, but really I just want an answer from EVS. Copy of orig. message below.  <Steve, I see no problem just using the alkalinity booster. I really dislike the two part supplements for the very reason you are stating. I've tried those once and was in the same boat you're in. Most of the two part supplements have to be purchased in two parts even though you have much left of the other part.  Much better to use products like SeaChem or Kent Marine. These companies DO respond to their customers. James (Salty Dog)>  Thanks Steve 

Re: Fw: B-Ionic Calcium Buffer System Dear Crew, I did get an answer..... Steve <Ahh, thank you for sharing. Will post. Bob Fenner> In a message dated 4/24/2005 " Dear EVS,  When using your 2 part buffer system can you use just 1 of the solutions. Example: my calcium is at 425 and my alkalinity is at 7.2 can I just use part 1 to raise my alkalinity? Also if the situations were reversed and I wanted to just raise my calcium could I just use part 2? Thank you for your time in advance. Steve" Steve, Sorry for this late reply. No problem using more of one component than the other in order to tweak the chemistry back in balance. Be careful with the component 1 (alkalinity) in that you don't exceed 1 ml/per gallon per day and/or allow the pH to exceed 8.45. Best Regards, Bob Stark (ESV)

High Calcium & Alk Hello! <Hi!> I would like to thank you in advance for your time and apologize for the length of my email. <No worries...We enjoy answering questions> I have an established (18 months) 125 gal saltwater tank. I am using a sand substrate 2-4 inches (varies from spot to spot because some of the fish move it around) with 135 lbs of live rock.  My water parameters are calcium 405, magnesium 1150, alk/dKH 12, <A calcium and alkalinity that high is a difficult feat to accomplish. I would be careful of letting them get out of hand and rising too high> ammonia 0, nitrite 0, nitrate (impossible to get a clear reading was using coral vital <You would be wise to leave that "snake oil" out> but I have stopped adding it for last 2 weeks and don't plan on continuing) after >calculation 7, Strontium off the chart >40, pH 8.2 in the am, iodine .08, sg 1.024, temp 78-80. <All sounds good>  

- Balancing Chemical Equations - All, <Good morning, JasonC here...> When Calcium Chloride is added to water, you get wanted calcium ions and unwanted chloride ions.  Does Sodium Bicarbonate (baking soda) break up into sodium ions and bicarbonate ions? <Oh man... general chemistry seems so far away right now. I think for the basics, yes this is true.> If so, wouldn't the chloride ions combine with the sodium ions to form NaCl, salt?  It probably isn't a perfectly balanced equation, but it seems that it could mitigate the usefulness of calcium chloride. <It would seem that way, but there are other reactions taking place in a marine system that would also need to be taken into account. What those reactions are exactly is escaping me at the moment... but on the simple path, I think this is true - you would produce salt.> If each is added in *small* quantities, say Calcium Chloride in the early a.m. and Sodium Bicarbonate in the early p.m., couldn't they become a useful adjunct to regular Kalkwasser use, if Kalkwasser alone was not supplying enough calcium to meet the daily demands of a given system (as is my case). <Well... if you look at a bottle of ESV B-Ionic, you will find that their part A is calcium chloride, and part B is sodium bicarbonate, and part B buffers part A. So in effect, this is similar to the reaction you describe. I'm not a huge fan of Kalkwasser myself - much to easy to get into bad trouble with. You might want to consider a calcium reactor - the cash outlay is perhaps a little high up front, but in the long term will save you money, grief, and is much better for your system than calcium chloride.> Thanks in advance. Sincerely, Mark Schwartz <Cheers, J -- >

2 Part Supplements Which 2 part supplement do you recommend for adding Calcium and Buffer (Kent  Tech CB, C Balance, etc.) <I always used b-ionic by ESV. They're all really the same thing and you'll be satisfied with any one you get.> I have a 125 gallon reef with fish and hard corals (torch, hammer, frogspawn, xenia). <Cool, just make sure that you pick up carbonate hardness and calcium test kits.> Thanks, <Enjoy! -Kevin> Steve

Establishing Calcium and Alkalinity <Hello! Ryan with you today> I have a 58g reef tank that I started about  2 months ago.  I have 70lbs of live rock, 40lbs live sand, 2 clownfish, 1 Kole tang, 10 snails, and 5 crabs. <OK> I have a Euro-Reef cs6-1 skimmer, 250w 10,000k metal halide light, 450gph sump pump and 300gph circulation pump.  I've start thinking about adding calcium to my system to get ready for corals and I can't decide which method to use. <Understood> I'm thinking Kalkwasser, 2-part calcium/alkalinity, or Seachem reef advantage calcium. <B-Ionic 2-part calcium alk is what I prefer> I'm looking for least maintenance, most idiot proof, and most effective. <Exactly why I prefer it> I would also like a recommendation for inexpensive test kits for calcium and alkalinity. <Seachem works well and is reasonable> What are your thoughts on the calcium situation and what are your thoughts on my setup so far? <Sounds great, you've got sturdy equipment list and you're taking it slow.  I'd add some live rock if possible, you'll want at least 1 pound per gallon.  Best of luck! Ryan> Your help is much appreciated.  Thanks,  Chris

- Shaken not Stirred - Hello folks! I love your site (best on the web) and really hope I didn't just miss the answer to these questions somewhere in the faq's. Hopefully you can help me out here. I was reading Anthony's article on calcium, in specific, the section pertaining to different sorts of supplements. He seems to be advising against using liquid calcium supplements due to a sort of ionic imbalance in the long run. He seemed ok, however, with using a 2 part system. Is there a reason that this is not a problem when using a 2 part system? <They are ionically (is that a word?) balanced. One part is buffer, the other calcium.> I currently run ESV b-ionic on my 75 gal reef and do not wish to have long term problems. <ESV is a fine calcium supplement.> It has shown me stable calcium around 420 with alk at about 10. Live stock seems very healthy with everything from mushrooms, buttons, Capnella, to Montipora reproducing or growing steadily. In fact, the only thing that doesn't grow is coralline algae! <Give it time.> Other than on the rock (approximately 110 pounds) I have no calcareous (sp?) at all. I run 2 96w (blue and 10k) pc's and 2 40w zoomed Reefsun. Calcium 420, alk 10, magnesium 1300, nitrates 10-20, phosphate 0. Is the lack of phosphate the limiting factor? <I don't think so. As I said, give it time.> Thanks, JL <Cheers, J -- >

Calcium/alkalinity supplements 09/09/03 Hello crew, <Hi Marty, PF on call tonight> I am looking for some clarification on two part supplements, specifically Kent A&B. I have a 120gal reef tank with a 100lbs live rock that has been up a running for 8 months. My livestock consists of a hammer coral, candy cane, open brain, green mushrooms, green star polyps and some brown and yellow button polyps. I also have a couple of tangs, clowns, Chromis, cardinals and some shrimp. I have been adding equal parts A&B daily and maintaining a fairly good balance. (12 dKH & 350 cal).  These are currently the only supplements I am adding.  I tested the other day and noticed the calcium was starting to creep down under 300 while my alkalinity remained at 12 dKH. I know that both cal/alk can not be simultaneously high, but I would like to get the calcium back up to the 350-400 level.  In reading the FAQ's I have found that the answer to increasing the calcium is to temporarily add calcium chloride until the target value is reached then continue on with the equal parts of A&B. Is this the same as just adding more of part A, in which the main ingredient is calcium salts?  I'm assuming that this is the same as calcium chloride. I just want to make sure I am not going to screw up the of the balance if A&B are not always added in equal amounts. I know the real answer to this question is to buy a calc reactor,  hopefully I will get there in due time. Thanks a lot for your help.  Marty <I would advise you to just use the calcium chloride, "calcium salts" implies more than one kind. And you're right, the real answer is a reactor. You might also want to look into adding Kalkwasser to your daily top off. Have a good evening, PF>

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