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FAQs on Calcium, Supplements involving Calcium, Rationale/Use/Importance

Related Articles: CalciumThe Use of Kalkwasser by Russell Schultz, Understanding Calcium & Alkalinity, Live Sand, Marine SubstratesReef Systems, Refugiums

Related FAQs: Calcium, FAQs 1Calcium, FAQs 2Calcium FAQs 3, Calcium FAQs 4, Calcium FAQs 5, Calcium FAQs 6, Calcium FAQs 7, & FAQs on Calcium: Calcium Measuring/Test Kits, Sources of Calcium, Calcium Supplements, Dosing, Chemical/Physical Interactions, Troubleshooting/Fixing, & Calcium and Alkalinity, Calcium Reactors, & FAQs on Calcium Reactors: Rationale/Use, Selection, Installation, Operation, Media, Measuring, Trouble-Shooting, By Makes/Models, &   Kalkwasser& FAQs on: The Science of Calcium & Alkalinity, Importance, Measure, Sources, Use of AdditivesTroubleshooting/Fixing, Products,

Both biominerals (mainly Calcium and Magnesium) AND alkalinity (principally carbonates and bicarbonates) are essential for biomineralizing growth and life. There is nothing wrong with a Calcium concentration of 300-350, even lower... with "all else" in balance... Really.

R2: Refugium Macroalgae, Calc. use, alg. contr.  -- 08/14/08    Hi Eric! <<Hi Jennifer!>> Thank you so much for the wealth of information and reaffirming what I've read about carbon. <<Ahh'¦my pleasure>> I keep a sponge in the bottom of the refugium to colonize bacteria for QT so carbon is not needed is that area. I'll try to raise the pH. I think I've read that increasing the calcium will help in the algae area...is this true? Jennifer <<Calcium itself won't affect nuisance algae growth, that I am aware. A calcium source like Calcium Hydroxide (Kalkwasser) will precipitate Phosphate which can help to 'starve out' the nuisance algae, but I don't feel simply bumping up Calcium levels with something like Calcium 'Chloride' for example, will have a malaffect on the nuisance algae. In fact, the accumulation of Chloride ions may well have just the opposite affect if it depresses pH. Cheers, EricR>>

Calcium Use/Supplementation (Never A Matter Of Just Dumping Some In)    8/14/08 Whoa...guess I've got some research to do on calcium. <<Research is always good [grin]'¦and best if collected from divergent sources. Do also read-up and understand the correlation of this bio-mineral with your systems Alkalinity and Magnesium content'¦which by the way, can be affected in differing ways by the 'type' of Calcium supplement utilized (e.g. -- Kalkwasser use can result in lowered Magnesium levels). Don't misunderstand; I feel Kalkwasser as well as the aforementioned Calcium Chloride from our previous exchange both have a place/use in the hobby, but use of these; or any other supplement, without understanding its effect on your system is dangerous. Here's a few links to get you started: http://www.wetwebmedia.com/calcalkmar.htm http://www.wetwebmedia.com/mgmarfaqs.htm http://www.wetwebmedia.com/calcalkfaqs.htm http://www.wetwebmedia.com/caalksci.htm http://www.wetwebmedia.com/caphyschem.htm >> Can I use calcium hydroxide even if I don't have a Kalkwasser? <<Mmm, did you mean to say a 'Kalkwasser reactor?' The answer to that would be'¦yes! If you don't have a reactor, I think it is best to supplement Kalkwasser using the 'drip method' to replace evaporation'¦but another way is to use what is called the 'slurry method' which involves adding a small amount of Kalkwasser (e.g. -- 1/4tsp to start) to cup of RO water, whisk briskly, and add all to the tank. Both methods require careful monitoring of pH (best done with an electronic meter in my opinion) to preclude effecting too great a rise. Here's another link to more info and opinions re: http://www.wetwebmedia.com/kalkh2ofaqs.htm >> Thanks for all of your help, Eric!! Jennifer <<Happy to share! EricR>>

Quick Calcium Question? (And a Start On The Road To Enlightenment?) -- 02/06/08 Hi people. <<Greetings, person>> Howzit? <<Hanging in there'¦>> As always, thank you for your help over the years. <<Quite welcome'¦is quite the collective effort here>> Quick calcium question. I have a month old 72g reef that is using 40g of 5 month old reef water (upgraded the size of tank ). When taking care of the 46g reef I had trouble getting calcium over 400. Dosed as needed. <<A common, and commonly misunderstood, situation>> Never stayed above 400 for very long. <<Did you ever check the magnesium level?>> When I set up the 72 I used the same salt, same makeup water, DID NOT DOSE with anything. Just made up about 40g of new reef water. Now, a month after running, the calcium is just above 500. <<You did state above that you brought over 40g of water from the old system'¦was likely 'saturated' with Calcium from the dosing>> Alk is 9.1. <<dKH I presume? Is best to be near the bottom end of the acceptable scale here, as you are>> I know ALK and calcium are dependent on each other <<Not so much dependent as are mutually exclusive of each other'¦but I think that is what you are getting at>> so do I just dose alk slowly until the calcium drops? <<Mmm, no'¦ In fact, I would let the Alkalinity drop a bit further (closer to 8 dKH) to try to preclude a precipitous event>> Is 500 okay? <<Higher than desired in my opinion'¦but should be okay for the short-term if you don't do anything to boost Alkalinity>> I do have clumpy sand which I stir every Sunday when doing the water change. <<You possibly have micro-fine crystalline precipitation occurring (too fine to see). Be sure to check/adjust/maintain your Magnesium level to preclude a more overt reaction as a deficiency of this ion may facilitate precipitation of Calcite (Calcium)>> Is clumpy sand harmful?? <<Only in the sense that it impedes the movement of infauna, as well as efficacious bacterial colonization, and subsequently the biological functions of the sand bed>> Hint: As of now I have no calcium needing animals, just trying to get that coralline. <<And another important reason to ensure a 'balance' of Calcium, Magnesium, and Alkaline elements'¦perhaps a large water change is in order'¦>> It will be a SPS and a few LPS tank. Got the Hamilton 2x250, so the plans are there. Last question...do I want to keep it at 500 so that when I do get some SPS's there's plenty? Or do you just always want to shoot for 450? <<Though popular among so called 'SPS keepers' to keep Calcium levels greatly elevated, I don't consider it necessary, nor is it often particularly easy to accomplish safely. Mimicking NSW levels as closely as possible for all Alkaline/Bio-mineral content is my suggestion. At the least, you need to have a thorough understanding of their role and relationships to one another. Please start reading here and follow the links in blue for further information: http://www.wetwebmedia.com/calcalkmar.htm >> Please enlighten me. <<I hope to have made a start>> Thanks. <<Regards, EricR>>

Calcium levels   12/6/06 <Greetings, Mich here.> How long can corals maintain sound health in water with diminished calcium levels ?   <All depends...type of coral ...soft versus stony, how low is the actual calcium level, levels of other minerals in the water... lots of variables.> I keep hearing hobbyists refer to calcium levels as  a lifeline for invertebrates. I realize the importance of calcium as a building block, and its' key role in water chemistry, but reports of mortality due to short-term drops in calcium levels seams implausible. Knee jerk reactions to this "falling sky" lead to yo-yo water chemistry, in both senses of the term "yo-yo". <I would tend to agree.  Stability and consistency can't be overrated. -Mich>  

Is Calcium also important for fish only tanks? If I setup fish only tank (with DSB and live rock) is supplementing with Ca also necessary? What is the LEAST amount of Ca that fish will tolerate? What about soft corals... do they need high Ca levels, just like stony corals?<Have found a some articles that should help you with the calcium questions  http://www.advancedaquarist.com/issues/feb2003/chem.htm http://www.advancedaquarist.com/issues/nov2002/chem.htm http://www.advancedaquarist.com/issues/apr2002/chem.htm http://www.advancedaquarist.com/issues/mar2002/chem.htm > Thank you,<IanB> Luke

Stupid problem, Calcium Snowstorm <Anthony Calfo in your service... Bob is participating in some bizarre human taco competition> Apparently I was getting false low readings from Salifert ph test and added more buffer to raise ph. An apparent calcium fallout occurred and I lost a few soft corals.  <very sorry to hear it. Try being neurotic like me and test redundantly with different brand test kits <wink>> Then, the crabs, snails, and shrimp began to become immobile. The ph is about 8.6 and the alkalinity is thru the roof.  <"the solution to pollution is dilution"> I have done 5% water changes for each of the past 3 days with no measurable decrease in those parameters.  <nowhere near enough water exchange, my friend> I have discontinued Kalkwasser and the calcium has dropped to about 150.  <alas... the double edged sword to a precipitous snowstorm... to add more would fuel the reaction... need to dilute the carbonates, goombah> I thought it best not to worry about the calcium level until the ph comes down to at least 8.4 and the alkalinity comes down.  <not exactly... the pH is irrelevant and best if near 8.6 by day (8.3 by night)... what you need is to dilute the alkalinity. That will not come down naturally without calcium as your calcifying animals need both for skeletogenesis. There is the crux of the dilemma.> I am afraid of another calcium fallout. I have some Seachem liquid reef calcium and their reef alkalinity liquid. The inverts are doing better, but the corals still are distressed. No bacteria infections yet--thank god--but I want to remove the stress ASAP. The fish are unfazed. <good to hear> The tank is 100 gal with good flow, skimmers, etc. and has been running fully stocked for about a year with no problem. Before this problem things were growing and breeding (mushrooms, shrimp, damsels). Please advise and thanks for your time. <yes...do serious water changes until your alkalinity is closer to 11-12 dKH. Only then should you resume Kalkwasser and/or liquid calcium to get free calcium levels up. Use baking soda very sparingly in between to keep your pH above 8.3 Kindly, Anthony Calfo>

Calcium (and iodide/iodine) hello guys, I have a quick question. am a bit confused about the difference between iodide and iodine as supplements for my shrimp.  <different forms in solution. Iodide is "safer", Lugol's solution is a nutritive Iodine and more potent. Bob favors iodide, I favor Lugol's (iodine mixed with iodide)> calcium, do ya need it or does the sand, shells, etc in tank supply it.. <depends on draw from inverts in the tank... if low demand, water changes will bring enough in ... but do get a calcium test kit and aim for 350-450 ppm (the low end is fine)> thanks a lot. I only have two clowns two snails and two cleaner shrimp......Jennifer <ahhh...yes. Save your money for now on supplements. A small weekly water change will give you these benefits and so much more. Anthony>

Re: calcium reactor FOWLR One more question. Can I use a calcium reactor that is rated for less than my size tank since I don't have a large calcium user in the tank (FOWLR). Instead of the 'pro' units that handle the 400 gallon tank, was wondering if I could get the 200g rated units instead ? Thanks <indeed it is all and only dependent on your daily demand for calcium and carbonates in the system. Don't underestimate the need for calcium by calcareous plants, sponges and algae (like corallines!!!) on the rock. You may not be as safe as you think. Do tests with a Ca test kit to determine your tanks actual needs before making this decision> Jim <kindly, Anthony>

Best Method of Calcium Supplementation for Soft Corals Hello Bob and crew, I met you when you (Bob) spoke at the Desert Marine Society meeting a couple of months ago. I have a 2 month old 70 gallon reef tank with 100 lbs of Fiji LR, a Prism Pro Protein skimmer, about 2-3 inches of fine aragonite, power compact lighting, good water movement. Anyway, after a lot of thinking and research I have decided to keep only soft corals (and a few peaceful fish) in this tank. Regarding water chemistry, I use a RO/DI water with a very high quality salt mix. I age the water for a week with an air stone in the barrel between water changes. I do about a 10% water change weekly. <Very good.> At this point I dose daily with Iodine but have not been adding supplemental calcium because of conflicting information regarding the need to do so when keeping only soft corals. <Even soft corals use calcium for there sclerites.>  When I test for Calcium and Alk, my levels are in the range typical for seawater but not in the higher ranges recommended for coral reef tanks (I apologies it don't remember the exact levels and my log is at home as I write this). <Glad to hear you have a log book. Actual numbers would be helpful, but I will give you some suggestions based on the assumption you are around 300 ppm Calcium and 3 meq/l or 7 dKH (the lower end of the acceptable ranges).> So, my question is should I be supplementing calcium? <Probably, yes.> If so what is the best way to do so with my system? <I would use ESV's B-Ionic two-part system. It is not cheap, but very easy and you do not have a high demand in your tank (should not be using too much). Be sure to continue to test, monitor, and track the trends of calcium and alkalinity.> I should also tell you that I don't have a sump and do not plan to add one to this tank any time soon. Thank you very much for your help! Pam <You are welcome. -Steven Pro>

Calcium Supplements Bob, re: Should I be testing for Ca to see if I NEED to supplement? <If your animals require it, yes> I have 4 fish (2 percula clowns, a yellow tang and the engineer goby), live rock with macro algae, a bunch of assorted crabs and snails. Is calcium important for these types of animals? If so, what level of Ca should I try to maintain?  <For the fishes, yes indirectly... in concert with other minerals, calcium serves to maintain pH, alkalinity... overall chemical balance. For the algae and invertebrates much more directly yes> On source I have suggests that it is important and that a level of 450 ppm is good. Do you agree? <Hmm, yes... please see the www.WetWebMedia.com site re "Calcium"... anywhere between about 350-400 ppm is fine... too much less or more is undesirable. Bob Fenner> Thanks, John

Calcium at 350 a bad thing?? I think not - 7/23/05 Good morning WWM crew: <Mornin' amigo, Ali here> Thanks so much for a great forum that has helped me so many times I've lost count. Ok now to my question for today. I have a 72gal bow front with 110 lbs of live rock, Remora Pro hang on skimmer and UV sterilizer unit (believe it or not the UV has saved me a couple of times). I did a full water param.s check last night and it looks like this: SG: 1.025 PH: 8.3 ALK: Normal (my kit doesn't give me numbers) Ammonia: 0 Nitrite: 0 Nitrate: 0 PO4: 0.05 CA: 350 <Not bad..> Note the low number in the calcium department. I have tried several products to get the CA up to 400 or a little better to no avail. <What's the big deal about going above 400ppm?> I have used Purple Up, Seachem Reef Calcium, and Kent calcium products. The number never seems to go above 350. <As long as your calcium readings are stable at 350ppm you are good to go. Full blown Acroporid reef systems, maintained at 300ppm can experience phenomenal growth, coloration, etc. etc. Point being - you don't need to have super high readings of calcium to properly maintain a healthy reef aquarium. Especially if your system contains mainly Soft corals and perhaps a few 'LPS' corals. The key to the whole thing is stability. If you can successfully maintain your calcium readings at 350ppm, it would be far better than having readings of 400 one week, 300 another week, 500 the week after, down to 250 the next. A stable 350ppm calcium reading is nothing you should be too worried about. As of now, focus more energy in a means to bring your phosphate levels completely down to zero.> My Toadstool Leathers really don't polyp as often as they should. They spend most of the time looking like a leather pad, and recently a couple of branches on my Torch Coral died off. I also noticed my very large button polyp rock is now dieing off too. The rest of the corals are doing fine. <This has nothing to do with your calcium readings whatsoever. Keep your fish bioload low, increase water change frequency with clean RO/DI water and relax a bit with all of the additives. A good two-part calcium/alk. supplement such as C-Balance or B-ionic is all that you need.> Can you recommend a good calcium product that will help me increase the number. Also can you offer advise on helping the leathers look healthier. <Increased water circulation/current, followed by the above recommendations will go a long way.> Thanks in advance ... Ray <No sweat Ray, good luck and keep researching my friend. - Ali>  

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