FAQs on Calcium, Supplements involving Calcium 2 Related Articles: Calcium,  The Use of Kalkwasser by Russell Schultz, Understanding Calcium & Alkalinity, Live Sand, Marine Substrates, Reef Systems, Refugiums,  Related FAQs: Calcium FAQs 1,  Calcium FAQs 3,  Calcium FAQs 4,  Calcium FAQs 5,  Calcium FAQs 6,  Calcium FAQs 7, & FAQs on Calcium: Rationale/Use, Calcium Measuring/Test Kits, Sources of Calcium, Calcium Supplements, Dosing, Chemical/Physical Interactions, Troubleshooting/Fixing, & Calcium Reactors, Kalkwasser & FAQs on Calcium Reactors: Rationale/Use, Selection, Installation, Operation, Media, Measuring, Trouble-Shooting, By Makes/Models, &  FAQs on: The Science of Calcium & Alkalinity, Importance, Measure, Sources, Use of Additives, Troubleshooting/Fixing, Products, A number of formats are used to (re) supply calcium to aquarium systems, algae, animals... one is "ground up" skeletons... Like Walt Smith's Fiji Gold.

By The Numbers.... Dear Crew, <Scott F. your Crew Member tonight> I have a new 20 gallon minireef with 20 lbs. live sand and 20 lbs. live rock.  It completed cycling 2 days ago, and I go back for 20 more lbs. LR and the cleaning crew tomorrow.  I use DI water and Coralife salt mix.  I have salinity at 35 and SG at 1.026 (in an attempt to mimic natural seawater as best I can).  My salt mix tests out at a pH of 8.0, alk of 3 meq/L (or approx. 8.4 dKH), with a Ca level of 510 ppm. <Wow! That's really high....> This last figure seemed a bit high to me, but I thought maybe it will work out well once I put my LR and LS and critters in.  (I ran the system with just the salt water for three days before adding anything to get a good feel of all the equipment, evaporation, etc., as this is my first marine and reef tank.)  The current tank water tests out as follows: ammonia - 0, nitrite - 0, nitrate - 4 mg/L, Ca - 500 ppm, pH - 7.95, alk - 3 meq/L.  I am concerned about that high Ca and relatively low pH.  Hangers-on with the rock included several species of sponge (including a beautiful 3.5" pink vase sponge, orange ball, various encrusting and boring, red finger), several anemones (sponge, turtle grass) as well as a gorgonian of some sort and several other little mobile creatures (snails, crabs, etc.) and sessile things as yet unidentified.  I lost a couple of the sponges in the cycling, but want to keep the rest.  Anyway, I am afraid to use a 2-part Ca buffer to raise pH since my Ca is already so high. <Well, the alk is quite adequate...And is a good indication that your system can hold it's pH to a certain point...When did you take the pH reading? As you know, it is often lower right after the lights come on...> One more thing -- I have only been running my lights 5 hours per day until the cleaning crew arrives, so I know that is a factor.  Should I do anything at this point to raise the pH?  Just leave it be for a little while longer? <Yep- I'd leave it be...> I would use Kalk but w/ the 20 gallon and no sump, this would be really difficult.  Any help would be greatly appreciated. Thanks so much! Erin <Well, Erin- you're doing a great job with regular testing. However, if it were me, I'd do exactly what you're thinking...Give things a bit more time, and wait until you can ramp up the lighting for a longer photoperiod. Also, don't get overly fixated on specific "numbers", as we hobbyists tend to do...Yes, it is important to achieve certain minimum water quality targets, but it is not worth you tearing your hair out! Just relax and let your animals "talk" to you...If things are out of whack, they'll tell you in many ways- believe me! Perform aggressive and appropriate regular maintenance (water changes, etc). Just hang in there- You're doing fine. I'll bet that the pH will correct itself in time...If not let's talk again...Good luck! Regards, Scott F>

Calcium/Alkalinity Dance Hello again.  I have been having a problem that I hope you can help me with regarding the calcium and alkalinity in my tank.  I have read over all of your FAQ's and articles on the subject, perhaps there is something that I am missing.  My tank: 90 gallon FOWLR-- 25% water change every 2 weeks 3 clown fish; 1 regal tang; 6 small mushrooms; 145 lbs of LR. pH-- 8.25 to 8.45 Alk. 11 dKH (pretty stable) cal. 250 ppm Over the past 6 months I have been dosing Kalk via the slurry method and adding SeaChem Marine Buffer.  This has resulted in excellent coralline growth and other growth on the LR.  I used to add 1 teaspoon of Kalk before lights on every day and alternating: 2 teaspoons of Marine Buffer and 3/4 teaspoons of Kalk at midday (Kalk one day, Marine Buffer the next).  The reason for adding Kalk twice on one day and once on the next day was to not spike the pH too much).  2 months ago my calcium was a stable 340 ppm and my alk. was 11 dKH.  Wanting to slowly bring up my calcium levels (around 400 ppm) I started dosing 1.5 teaspoons of Kalk everyday before lights on and alternating-- 2 teaspoons of marine buffer and 1 teaspoon of Kalk at midday. I slowly increased these levels over a period of 7 weeks (I test weekly for cal. and alk.)  One would think that this would result in increased levels of calcium.  NO!  Now it is lower, 250ppm.  I have not had a snowstorm.  Nothing else has changed in the tank over the last 6 months.  Is my tank suddenly consuming more calcium?  Or is there something possibly wrong. My magnesium is around 1200 ppm, if that helps.  Thanks. <Well, it seems to me that you've got a pretty good read on what's going on in the tank. It's a real balancing act, as you know, to keep both high alkalinity AND high calcium levels (in fact, down right impossible for most people). I think that this is one of those cases where you'll have to be glad that you have good alkalinity, and accept the calcium where it is. The fact that your coralline is growing so well is a testimony that you're doing something right. If it were me, I would not get overly frustrated about it...Just keep doing what you're doing, monitor the water parameters, and enjoy your tank! Some might disagree with my assessment, but I think that you're fine here. Maybe not the technical answer you might have expected- but it seems to me that you are getting fine results...just not the number you want to see on the test kit...I'd relax...Good luck! Regards, Scott F>

Calcium Troubles After having reviewed the correspondence below, I would have to recommend that this is one of those rare instances where a CaCl supplement maybe in order. With calcium levels being the only parameter out of whack and with your tank's apparently very high demand for calcium, this option gets you back on track and hopefully after that you will be able to maintain with your Ca reactor. The only other option, and what I generally recommend, is to perform a series of large water changes to correct. I would do 50% every other day until you get the everything back on track. The only problem with that is the cost and time when you take into consideration your tank's demand. You are going to have to go through a lot of salt and labor to keep up the pace with your tank. Sincerely, Steven Pro <Thanks much Steve. I concur. Bob F> Hi Bob, I have a calcium related problem that you may be able to help me with as after reading all of the information posted on yours and other websites I am at a loss for what to do. A while ago I installed the Dupla Ca reactor that we talked about. You might recall that the media supplied with this unit was very poor in terms of solubility and Ca output. The situation has not improved and I am still awaiting the arrival of some Korallith media from Diana (should hopefully arrive in the next week or two). My tanks calcium levels have fallen to 200ppm as measured by a Hagen and Red Sea tests (both agree and are new). Alk is 120ppm, phosphate 0ppm, nitrate 0ppm, Ph between 8.2-8.5. The tank holds approx 700L, and is packed with live rock, moderately stocked with various corals, a clam and several fish (blue tang, yellow tang, two dwarf angels, bicolour blenny and 5 damsels). (see photo) The question is, until I can get hold of more suitable reactor media how can I raise the calcium by 150-200ppm without creating other complications with ionic balance etc. I have already performed three large water changes (35%)with an Australian salt mix that has 400ppm Ca but this only pushes up the Ca by about 70ppm to then only fall again within a few days (clam and coralline algae really growing well and sucking it up I suspect). I have been dripping in 5 litres of saturated Kalkwasser (made according to Seachem instructions with RO water), but 5 litres dripped in overnight will only raise the Ca of 150L of water by 24mg/L. I have 700L of water that I need to raise Ca in. A quick calculation suggests that I would need to drip in 17L overnight to raise the tanks water by 24mg/L. This is obviously impractical and would probably spike the pH (and at the same time my tank is probably consuming the Ca at this rate). Other options include: 1. The liquid SeaChem supplements available in Australia (reef complete and Calcium) are from what I can gather not really suitable due to problems with ionic balance etc. 2. Kent marine turbo calcium but this (correct me if I am wrong) also has problems with creating water chemistry imbalances. 3. The 2 part Seachem powder additives Reef Builder and Reef Advantage. But again are these compatible. My question is which path should I take? Continued large scale water changes will only stress my fish and livestock (water is mixed properly with RO, buffered and aerated etc for several days before). The volumes of Kalkwasser using a drip method are two big to add and I am not sure about the other products? Can you please give some best bet some suggestions as to what to use until I get the Ca reactor back on track? I realize that there is probably no easy answer on this one. Another piece of information just in, is that Seachem are apparently going to export an aragonite media to Australia, pending Quarantine approval. Are you familiar with this brand and how it stacks up as it may be the only other option to Dupla in Australia. The other medias are technically not allowed into Australia due to Quarantine issues. Your help would be really appreciated on this one. Cheers, Paul Grundy <Paul, I'm forwarding your query to Steve (Pro), friend, cohort here. He knows much more than I re these matters, individual products. Cheers, Bob F>

How to measure Ca Hi, I hope everything is doing well with all of you! <and you as well, my friend> I was reading the procedure recommended by Anthony in his book, and its sound easy, but I have a problem, I can't find reliable test for Ca.  <indeed... the liquid titrations are tedious and not clear. To some extent they are variable due to the differences in each of our eyes to perceive colors. But some kits are just plain inconclusive. For an inexpensive and reliable kit, I like Aquarium Systems brand> The first day I measure it with a Red Sea (liquid) reagent and it shows 300 ppm (scale from 50 to 50) that nigh I dosed one glass of super ultra archi full loaded and hypersaturated solution of Kalk (wink as Anthony says) the very next day I use the meter again and it show only 300, so that night I dosed again another glass (concentration 1/8 tea spoon) the next morning the same... 300, so I repeated everything but the same reading 300... The Ca is going up, I'm sure, because the red algae is growing at a seeing rate, my 3 shrimps are changing its skeleton, and my only Halimeda bush increase at least one leaf at day... <excellent... and agreed. The Ca is certainly going up. I have heard many complaints about the Red Sea test kit specifically.> I know you can said that my tank consume 50 ppm by day, but I'm not sure at all, you will see my tank is not full (I presume) of Ca demanded inhabitants <yes... 50 ppm is really a lot! It is unlikely that the demand is that high although possible> 200 lts (50 gallons) 35 pound live rock (almost with nothing over the rock) 2 small (1 inch) cinnamon shrimp (cleaning family) 1 medium (2 inches) boxing shrimp 4 turban snails (their are growing since I'm using Kalk) 2 damsel fish 1 yellow tang 1 little colony of small polyps a spot of Halimeda and... nothing more <yes... agreed... not 50ppm daily demand. The test kit is certainly inaccurate here> PH 8.3 (average) Ammonia 0 Nitrites 0 Nitrates 0 Temp 82? I don't want to dose more Kalk until I have a correct way to measure the Ca. I don't want snow storms... <very wise> Here I only found Red sea Reagents and they are liquid not dry as Anthony's book recommend,  <hmmm... that's OK. I can live with a liquid reagent if it is fresh and rotated often (do not keep longer than 6 months)> exist an digital device like PH meter from Hanna or something more accurate to read Ca?  <too expensive> there is another way to know how much Ca my system is using?  <yes... even with a less accurate test kit it is easier to test the daily demand by starving the tank of calcium for several days: test the Ca before you start, then test it several days later and divide the difference in drop by the number of days you went without dosing Ca. This gives you a more reliable reading> there are indirect methods to know if the Ca is too high (like high PH?) how many angels can I seat in one square feet? <heehee... unfortunately the indirect methods are not always reliable. Let me know what other test kit brands are available if you cannot find Aquarium Systems (the maker of Instant Ocean Sea Salt). Also, some of the big mail order companies here in the US frequently sell overseas like Marine Depot. Perhaps you could inquire about a special order if necessary> Thanks for your prompt answer, Carlos <with kind regards, Anthony>

Re: Calcium Question I am using SeaTest and Salifert test kits for calcium. I also took some water to the LFS today and they said my levels of calcium were at 270ppm. You said I might be dosing too fast? I am dosing about 1 1/2 liters of freshwater with 1/2 teaspoon of Kalk at about 1 drop per second at night. I am dosing it into my sump right next to the inlet <fair enough... sounds slow enough for dosing. We've exhausted the likely causes. Do test your magnesium levels to see if they are skewed with Ca/Alk. Magnesium should ideally be about triple Ca (1000-1200 ideally). Best regards>

Calcium and Test Kits Crew, <<Greets...>> I just wanted to add my observations to the discussion on today's question and answer page about calcium concentration and suspect test kits. I thought I had the same problem earlier this year. I was beginning to add calcium to an 8 year old tank (FO) to which none had been added before and was monitoring calcium and alkalinity. Calcium levels were not rising (alkalinity was improving) and I suspected either 1 the test kit, or 2 my forest of cancerous Halimeda. Through persistence and continued monitoring I have finally gotten the level up into the mid 300ppm (Salifert kit) and my alkalinity is maintained around 10dKh. It has taken months and nearly a gallon each of ESV's two-part product! <<Time for a calcium reactor...>> My explanation is that the tank has been deficient for so long that the substrate and live rock have absorbed it back to reach "equilibrium" levels. Am lost as to what else it could be - the fish? <<Not the fish either, just not really possible to pour in calcium and get a perfect reading in one day, and quite likely the forest of Halimeda was sucking it back out just as quickly as you put in the calcium. Sometimes very hard to get ahead of demand.>> I have also noticed that at least for my system, the alkalinity moves much faster than the calcium when using this product. Given that the two measures are inter-related, calcium has a lot more 'momentum' in the reaction equation than alkalinity. Thanks for the great work you folks do! <<Glad you find it helpful.>> David <<Cheers, J -- >>

Ca Chloride and 2-part Additive Question Hello there, I have read that Ca Chloride is "bad" for my tank, in the long run. <Yes> I use a two-part additive called Oceans Blend, which lists chloride as one of its ingredients, but it's mixed with a ton of other elements (essential elements, carbonate, etc) and appears to be "balanced." <Correct> When the literature/FAQ's state that chloride is bad, are they referring to things like Turbo Ca, which is just Ca Chloride (i.e., additives that are Ca Chloride only) <Yes> or do they mean anything with chloride in it? <No, actually your salt mix has chloride in it. It is all about balance. These two part formulations are designed to add calcium and carbonate along with many other things.> If so, do other 2-parts like B-Ionic contain chloride? <Yes> I have read good things about this product and may switch if this is a safer additive. BTW, I'm gonna throw this question out to the chat forum section on the site to get more input. I hope this is not considered rude/bad etiquette. <No, we always recommend other seek more advise and knowledge so they can make their own informed decision.> Thanks a bunch, -RY <You are welcome. P.S. Your question shows you are reading and thinking a lot. Kudos to you. -Steven Pro>

High Alkalinity & Calcium Hello, My alkalinity and calcium seem quite high for my FOWLR tank, yet my pH stays rather low. Alkalinity is 5 meq/L, calcium is 450, and pH ranges from 8.0 to 8.2. <These are all fine.> Are these numbers anything to be concerned about? <No, not really. As long as they all stay consistent.> What is the best way to get my pH up without getting my alkalinity and calcium any higher? <Aggressive protein skimming to remove dissolved organics that affect pH.> I've added quite a bit of Macroalgae and that has helped somewhat. <Yes, helps in several ways; taking up the dissolved organics mentioned above and also consuming CO2 during the daytime.> Thanks for your input. Chip <You are welcome. -Steven Pro>

Re: High Alkalinity & Calcium Steven, Thanks for the reply. As a follow-up, my AquaC skimmer (only 4 weeks old) occasionally goes on 'strike' for two days or more after a water change and after I've had my hands in the tank. Is it normal for it to go this long without skimming? <Yes, it is disrupted briefly.> It eventually resumes, but it just seems to take a while. Also, I will be putting a raccoon butterfly in this tank. I've read on WWM that they like higher pH and salinity. My salinity is currently 1.023. Should I increase it for the butterfly? Is my pH (8.0-8.2) okay? <I would increase both to natural seawater conditions; 1.025 and 8.4> Thanks again, Chip <You are welcome. -Steven Pro>

High Alkalinity & Calcium III Steven, Thanks again for the reply. Okay, so how do I increase the pH without raising the alkalinity and calcium? <Water changes, protein skimming, activated carbon, etc.> And is the 8.4 you suggested the LOWEST the pH should go? -Chip <About average, anywhere between 8.2-8.6 depending on time of day, supplements used, lighting, photosynthetic animals, etc. -Steven Pro>

Calcium reactor media <<Greetings, JasonC here at your service...>> I only recently found your website, but after reading through most of the FAQs and articles, I haven?t found an answer to my questions. I am just setting up a 180 gallon reef aquarium, and in the process, am learning about using a calcium reactor with it. I have a K2R reactor, 20 lb CO2 canister, regulators with solenoid. I have a ph controller as well. Two questions I have are: can you use crushed coral as the reactor media rather than purchasing more expensive, processed media (I would be performing an acid soak/wash using Muriatic acid overnight, followed by rinsing numerous times, then neutralizing with baking soda, and then drying before using in the reactor ? expect that this would remove a good percentage of the phosphates and silicates)? <<Yes you can definitely crush and use coral skeletons, but I doubt seriously that you need to go through any additional steps. Just throw it in the reactor.>> Second, I haven?t found any good information or instructions about using a pH controller with a calcium reactor, just a lot of people referring to the benefits of using it. Should it be used in controlling the CO2 solenoid based on the effluent pH, or the tank pH? I had planned on using it in the tank. <<Tank pH might be preferable. You would be able to stop the pH from diving too low.>> If I use it in the tank, what are the best parameters to use (i.e.: what pH to have it activate and deactivate the solenoid)? <<There is no set answer, it depends on your tank. Rule of thumb, if pH is going below 8.2... turn off the bubble machine, as Mr. Welk would say.>> Thanks for any help you can provide, and I expect I will be turning to you no and again for additional help as well. Dr. Mac <<You might want to check out this article on WWM: http://www.wetwebmedia.com/calcreactors.htm Cheers, J -- >>

Calcium Reactor Hi Bob or Anthony, Thanks for the Calcium reactor info. Before I buy, a question on my current practice and what is better. I used to dose Kalkwasser, but I found it time consuming (I will review the archives to help with this!)  <yes... and I think I excerpted my short and sweet "slurry" method for dosing Kalk from my coral book in the FAQ's as well. Kalk is VERY easy to dose in this manner by following a few simple rules>  I switched almost two years ago to Tropic Marine Bio-Calcium 1-2 teaspoons/day just sprinkled in my sump, and periodic addition of Kent Superbuffer dKH when required. What is better my current practice or should I go back to Kalk.??  < I like Kalk and buffer better. Calcium hydroxide (Kalk) has so many more benefits over other calcium products based on Calcium chloride. For that matter... calcium chloride can really mess with your Ca/ALK dynamic in the long run. Yes... do review archives on this topic and follow up with unanswered questions> Thanks Larry <best regards, my friend. Anthony>

Output needle valve clogs on Knop reactor Hi Bob, <<I'm not really Bob, but I play one on TV. JasonC here...>> I've recently added a Knop calcium reactor to my 125 gal reef tank and I've had problems getting the drip rate to be steady because of rapid clogging. <<Ah ha! I have the same reactor and a similar experience.>> Do you have any other suggestions besides using the one Knop supplied? <<Well, I just added that to a list of maintenance things to do each week, but you could also try a metering pinch valve higher upstream on the effluent line.>> I've tried using a plastic 2 way gang valve but both became clogged almost as fast as the original Knop one (within a few hours). <<How quickly are you dripping? You want at least two drops per second with this reactor and at that rate it should take at least a week to slow down due to clogging.>> This of course results in the calcium reactor building a major air pocket below the media so that the pump runs dry. I'm using the siphon method vs. the external pump for delivery water is there any benefit to the external pump?) <<Well, this is also due the your choice of feeding the reactor with a siphon - only atmospheric pressure moving that water through those small lines. A little more back pressure applied by a small pump or inline plumbing would help with the clogging problem and also stop the air from collecting.>> Any suggestions / ideas you may have ,please feel free to write me back...Thanks, Shawn <<You got it... Cheers, J -- >>

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 Additions What's up guys? I have a 75gal fish only setup and just recently added my first live rock (only 20lbs.). Should I be adding a calcium buffer? <Before adding any supplement for calcium, you need to have a test kit. You must monitor your calcium levels and trends in relation to your dosing.> What level should I keep calcium at? <350-500 ppm depending on alkalinity level.> Do I continue to use my PH buffer (8.3) with water changes? <Same as above with calcium. Your test kit will tell you whether you need to or not.> Thanks, Mark <You are welcome. -Steven Pro>

Calcium supplements Hey fellas! What's up? Just a quick question, what's y'alls opinion of Bio calcium by Tropic Marin? <A very good product> Is it better/as good as Kalkwasser mixes? <Mmm, better IMO> It sure is a lot easier to use! I have been using it for a while now and it seems to be working good, just wanted to know what y'all think. Also, I would like to know if you think I could keep SPS corals healthy in my system, I have a 70 gallon tank with 440 watts of VHO lighting, 70 lbs of 9year old live rock and an old CC skimmer powered with a Tetra Luft pump. <I might renew/replace some of the old live rock... otherwise you're ready> I have been keeping corals for almost 10 years but have never tried SPS before. I have had several people tell me that you must have MH lighting for these animals, yet other people such as GARF) do not seem to have this opinion!? <Neither do I. Am familiar with folks who make a living culturing corals using PCs> What do y'all think? Also, one last thing, for the last 4 years I have been using a home made wave maker Radio Shack-$25.00) with good results set at 15 second intervals running 4 pumps,2 high, 2 low in rockwork, but have lately been reading about how bad laminar flow is for tanks, any suggestions on reconfiguring what I currently have or should I buy some sweeping powerheads, and if I do, should they be on a timer/wavemaker as well or just plugged in?  <Mmm, should be fine either way... as long as the water flow/force isn't overpowering whatever life you have it directed at> Y'all have a great site and do a great service of separating Bunk from Knowledge! Thanking you in advance, Joshua Scialdone P.S. Guess this was more than one simple Question! Ha Ha Ha Thanks Again, Joshua <Be chatting Josh. Bob Fenner>

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>

Live Sand Mr. Fenner, <Anthony Calfo in your service> I begin by saying thanks for the amazing service that you and the WWM provide. A wonderful and invaluable resource that borders on information overload!  <yes... we have been told that we are really full of it many times<G>> I have been able to research numerous topics with your FAQ's and your added Google search engine! Thank you. <excellent to hear> My question is about live sand. I am seeing "clumps" of sand -- I tried that in the search feature -- and have noticed that the grains seem to be sticking together. <yes, I understand and can explain it> Tank info: 58 Gallon + Wet Dry Ceramic Media)/skimmer + HOT Magnum Ammonia 0 Nitrite 0 Nitrate >10ppm pH 8.1 dKH 10 Calcium 400 I add the Kent CB as the tests warrant and had been using Aragamilk. <bingo... misapplication as part of the problem> My sand "crew" includes: <this has nothing to do with detritivore activity> Sand sifting star, Over-achieving Dragon Goby, <yes... Amblygobius phalaena: this goby is one of the very best and most hardy!!! for sand sifting. I love them> 10 Blue-legged hermits, and a Blue Damsel that has taken to re-arranging the sand in three of the four corners of the tank! What do these clumps indicate about my water chemistry?  <it is exactly precipitated (literally) by wildly fluctuating chemistry. Perhaps unnoticed by you if you test your pH at the same time every day. Some folks get it by pouring in Kalkwasser solutions too much or too fast which causes a temporary spike in pH locally. It may occur from the misapplication of other Ca or Alk products (like your Aragamilk product.. of which I am dubious about its benefits in the big picture) when used too much or too quickly (smaller more frequent dosing is better than large weekly doses. And finally it can happen in tanks (receiving such products or not) that have wild "natural" swings in pH between night and day. I see that you report a pH of 8.1. If this is accurate and a reading taken by day as I suspect (when pH in aquaria is highest by far)... then you have a borderline serious problem with pH. You may actually be dipping down to 7.8 or lower at night (tank respiration). And this is all assuming that your test kit read accurately! What if the kit read high? And your day night readings are actually 7.9/7.6...yikes! No wonder then aragonite in your bed is fusing.> Or is this supposed to happen?  <nope... an indication of a minor flaw in the system that could turn into something bigger. Still not much to worry about> Everything looks fabulous but I am noticing more of these little sand "balls" every day.  <yes... do examine your dosing system and day night pH swings (take a test reading after a long dark night before the lights come on and not after a fresh dose of ca/ALK)> I really did try to find this mentioned in the FAQ section and under LS but I may have been looking for the wrong thing. <appreciate you taking the time to look... hopefully you found other interesting things> Thanks for all your hard work and for sharing your expertise. Have a wonderful day. Lee <best regards, Anthony>

Calcium Bob, <Actually, Steven Pro right now.> I did some studying and I have been able to maintain 3.0 meq/l of Alk and a pH of 8.2. Over a five day period I have been able to maintain the above parameters. I tested everyday and my SG is 1.023. My calcium has depleted form 350 ppm to 300, there is not a heavy amount of fish or invertebrates. I would like to raise the calcium without lowering my Alk. Would a Kalkwasser drip be good enough to maintain a 350-400 ppm of calcium? Thanks <Kalkwasser is my current preferred method. -Steven Pro>

Another question about Calcium Bob, Thanks for all of your help over the years, I hope you know you are appreciated! Anyhow, I am at a crossroads with making a decision on Calcium Supplementation. I am sure you have heard this before but the issues as I see them are: 1) I could set up a top off system,( which I will be doing in any case) and buy/make and Nilsen reactor. Obviously, PH is an issue and as a natural combatant of Phosphates, this may be a nice option. <and one that I favor strongly> 2) Do a freshwater top off but supplement Calcium with a Calcium Reactor. This option obviously has some nice features in that trace elements, Alkalinity and Calcium levels will be maintained. This seems to be a more automated solution. <yes... but even Daniel Knop of Knop reactors like most experienced aquarists recognize and/or advocate Kalkwasser supplementation to reactors which are predominantly Alkalinity generators> The real question becomes, can an automated Kalkwasser delivery system provide everything that the reactor will?  <they are separate... Kalk/Lime provides calcium only and protects the buffering pool of alkalinity by virtue of its caustic nature (high pH). Reactors are predominantly for raising alkalinity although they certainly do contribute measurably to calcium levels. Aquaria with the fastest growth, if this is your goal, employ both. Do review our Archives and article by Jason C on this subject> I am assuming I will need to supplement a Alkalinity buffer with Limewater only.  <agreed> I know you can do both and maybe that is the best of both worlds.  <very wise my friend!> I would love to hear your opinion on the issues. Thanks! Adam <you know all that you need to continue on this wonderful journey! 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>

Calcium, the Bane of my Existence Dear Bob and friends <Steven Pro in this morning.> I have tried so many solutions (pun, sorry) that I am at the end of my rope. I have a lightly populated 55 gallon reef tank with 65 lb live rock, two years old and healthy in all obvious respects. Zero NOx's, etc. Calcium, however, has been abysmal since I started on an ill-fated program to raise Ca levels 9 months ago. I moved to a 4 to 5-inch DSB at about that time, which has been a success. Test and additive history follows. I tend to use the low end of recommended additives except as noted. Daytime pH has never wavered from 8.3. I used fresh Salifert tests throughout. I inject Aiptasia with a strong Kalkwasser solution every 3 or 4 weeks. Date Alk Ca daily additives 2001 Mar-June 10+ 330 stable, using Kent A&B July 8.3 325 stop A&B, add TurboCalc Aug 7+ 325 TurboCalc (1/2 dosage) Sept 6+ 315 same Oct 5.1 315 same Nov 7.2 300 Stop T-C, Back to A&B Dec 15 7.9 270 Start dKH Superbuffer&B Dec 29 9+ 230 dKH, stop A&B per LFS 2002 Jan 11 13.6 165 stop dKH, start A&B Jan 26 9.3 170 A&B only Feb 2 8.8 170 Start B-Ionic, stop A&B Feb 26 7.8 200 B-Ionic (1.5x dosage) Mar 23 8.0 200 same LFS finds Ca 310 ppm. Buy new Ca test kit. Apr 5 9.3 190 stop B-I, start dKH Apr 15 12.0 180 Stop dKH, start low-dose B-Ionic Apr 17 10.8 -- B-Ionic Apr 25 9.3 155 A-a-r-g-h-h !! How do I find my way out of this quagmire? <I would begin by doing some major water changes. Check your new water after it has mixed for calcium and alk. levels and adjust as needed prior to use. Once you have the tank's water in the proper ranges with the water changes, then attempt to maintain with one of the two-part solutions. My preference is for the ESV or Two Little Fishies products.> I have read the WWM calcium articles and FAQs without really learning much. (I am a mechanical engineer, but no chemist.) Could I have two bad test kits? <Possible, but you have double checked the calcium tests with two of your own and one from the LFS. The LFS's was the one that sounds off. Your alk dipped just as it should have July through Oct. 2001 when you were only dosing for calcium, so that kit sounds correct.> Newt <Several large water changes and all should be well again. -Steven Pro>

Calcium Level Hi Bob, <Anthony Calfo in your service> I'm having a problem along with everyone else on maintaining my calcium level. Currently it's been 700+.  <this is almost certainly a misreading my friend... if not an outright impossibility. Crystalline precipitation of calcium carbonate begins easily in most tanks by 500ppm. Anything over that is very difficult to even achieve. Do test this water with an entirely different brand of test kit. Try Aquarium systems ReefTest kits> I read your FAQ's and found that if you add backing soda to your Reef Tank, it will lower your calcium. However, it will raise you pH level.  <fast and temporarily... easily abused too> I have lost a lot of live rock and other creatures and I'm getting frustrated. Would you please give me some help on keeping my Reef Tank in proper condition such as the levels and what type of chemicals to use in maintaining my Reef Tank? God Bless, Peggy <no worries, my friend. I suspect your primary problem is the test kit, not the water. You could only get such readings by a repetitive and obscene overdose of calcium supplements. I discuss water chemistry for ref aquaria extensively in my book (http://www.wetwebmedia.com/bkcorlproprev.htm). If you are really ambitious, do pursue the works or Dr Craig Bingman... very learned and informative in his studies on water chemistry. Anthony Calfo>

Calcium Too High Bob, I was reading through your calcium section for some help, and you mentioned to one individual the ability to extract biominerals from a tank. My calcium is 680 and I've changed the water at 30% too many times. What can I do to extract calcium from my tank? <The easiest, fastest, likely safest way is the assiduous application of baking soda (sodium bicarbonate) solution... Applied in small dosages, nightly, with testing this will soon enough precipitate your excess solubilized calcium. Bob Fenner, in Australia for one more week... Home again hopefully before Jason, Steve and Anthony explode>

Snowstorms Ca/Alk <it seems highly unlikely... are you confusing a simple temporary clouding of the water with the catastrophic "snowstorm"? A "snowstorm" is a sudden and severe crystalline precipitation of calcium carbonate that looks literally like snowflakes polluting and aquarium an is quite dramatic! Your calcium/carbonate levels plummet within 12-24 hours and it can be fatal to many, most or all livestock in the tank at times. When you say "snow storming" this implies to me that it happens to you regularly and such a thing is nearly impossible within weeks (gross neglect would be necessary). We should be clear on this term first.> Ah. Perhaps I am overestimating the significance of the crystallization I see. I used to see just a puff of white when I poured the stuff in that resolved in 5 seconds. Now I see crystals (like snowflakes ) that cloud about half the tank for about 5 minutes, then go away. The only chemical derangement has been the chronically dropping KH that DOES correct when I add a bunch more buffer. So maybe what I see as a snowstorm really isn't very important. It hasn't killed anything. Thanks :) <excellent my friend, and yes...agreed (and glad to hear it too!). An easy mistake when you haven't seen the other side (thankfully) to know what it looks like. Try diluting your supplements in a larger volume of seawater before dosing or add slower to reduce the cloudiness. In the meantime, do consider the two-part supplements. They are a little bit more expensive but work so very well! Kindly, Anthony> Tracy

ALK, Calcium Greetings! <Cheers, Anthony Calfo in your service> I have what seems to be a fairly successful reef which has a TON of money into it and all life in there seems to be well. I have an open brain, magnificent anemone, frogspawn, green star polyp, and about 10" in fish. Here goes: 125 gallon, RO/DI water, 6" 175w MH/VHO Canopy, 180lbs. live rock, wet/dry, carbon, heater, chiller, Aquacontroller II, Aqua-c EV-120. Water parameters: 80 degrees, 1.023 SG, Ammonia =0, Nitrites=0, Nitrates=<2, Cal 380-400, Alk 2.5 meq/l, PH 2.3 at night - 2.45 during the day,  The alkalinity is too low and the pH is clearly a typo...resend please> My dosing schedule is: Monday & Tuesday dose 2.5 gallons/day of top off dosed with Seachem Reef Plus, Advantage Calcium and Reef Calcium, Tuesday and Wednesday - Reef Builder (raises carbonate alkalinity) Thursday and Friday, just advantage calcium, Saturday and Sunday, Reef Builder. Obviously the Alk is low and so is the SG. I am not dosing Kalkwasser.  <I strongly recommend Kalkwasser> What do you recommend to raise alk?  <common Seabuffer if using Kalkwasser or two part liquid supplements if using neither (like B-Ionic brand or Sea Balance)> Just keep doing what I am doing?  <heck no> Let me know your thoughts on just using the liquid and powder calcium chloride.  <calcium chloride should only be used alone in emergencies... it is plagued with problems for daily use in the long run> Should I supplement some Kalkwasser in the schedule?  <daily for optimum coral growth and saponification (improving skimmer performance)> If so, how often. Thanks! Adam <best regards, Anthony >

ALK, Calcium II Thanks for the reply Anthony! <very welcome> Follow up question for you or two. 1) Why is daily use of Calcium Chloride a problem? <accumulated chloride ions can skew the alkalinity/Ca dynamic.. making it hard to maintain alkalinity> 2) So, you would dose Kalkwasser daily and how often would you use a buffer? Is this an alkalinity buffer? <not a buffer directly, but reduces the amount of buffer needed in a system to maintain Alk while increasing Ca> 3) Do you see a problem with biweekly dosing of Reef Plus ( Vitamins and minerals for corals)? Actually they (Seachem) recommends just dumping 6 capfuls (for my 125) into the sump. <experimentally it sounds fine... I like regular water changes as much or better for this purpose. Anthony>

pH/Reactor advice Hi Guys: I would be most appreciative of your advice regarding my recently acquired reef aquarium. I moved it from Indianapolis to Cleveland about two weeks ago. 65 gallon with 25 gallon sump, running Berlin method. About 80 pounds of live rock. Berlin skimmer is oversized by a factor of three. Also has Knop C Calcium reactor. Actinic lights 12 hours per day; metal halides for 9 hours per day. Very well aerated w/ three powerheads on a Tsunami wave timer. Tank was running rock steady for three years in Indy. Tank is overstocked for my liking. I plan to give everyone larger digs in about a year. Current inhabitants include four fish (purple tang, six line wrasse, perc clown, and a flame angel), <A little dense for the long-term, but could be ok for now as long as you can maintain the water quality.> inverts (two Mithrax crabs, two peppermint shrimp, one pistol shrimp, black banded starfish), four soft corals, hard corals, and an awesome Samoa clam that is about 6-7 inches long. Current water parameters are ph 7.5 (low I know), <Wow> phosphates 0.05, kH 10.8, Ca 420. Bubble rate is 17 bubbles/minutes, drip rate is fixed by a gray orifice - no valve - at 190 drips/minute. Is this orifice standard Knop equipment? <I have no personal experience with Knop reactors, but I would cut back on the CO2 until you can get the pH back under control.> Their O&M manual IMHO is very poorly written. <Take a look at the piece written by Jason on them http://www.wetwebmedia.com/calcreactors.htm> I have an RO/DI unit. I aerate the water for 12-24 waters, raise the temp to 80F and buffer it with Kent Liquid dKH buffer and use this for makeup water. When making saltwater, I add Instant Ocean to the buffered mix. Any changes here? <No, your water procedure sounds fine.> Animals are doing great, fish vibrant/active, corals really extended, clam is happy as a clam although the last three days the tang has been picking on him pretty aggressively, especially during the actinic evenings, and the clam has been retracted quite a bit instead of hanging over its mantle as a result. I consider the positive appearances/activities of the animals one of the best measures of performance, to a point. <Yes, to a point. Many times the appearance of your tank is an accurate portrait of how it is doing. Other times, accurate testing can inform you of coming problems before your pets have responded, sometimes too late to take enough corrective measures.> My questions: Should I attempt to raise the pH through chemicals (Salifert 8.3 pH or Kalkwasser) or will it come up on its own with time? <It will not raise on its own.> I'm not wild about the Kalk, mainly because the dosing unit is cheap and hard to control. <IMO, Kalkwasser dosing is incredibly easy. Can be tedious to do it every night, but cheap and effective.> I'd also hate to artificially raise the pH just to watch it possibly fall back down to 7.5 two days later. <Agreed, you need to address the root cause of your incredibly low pH.> I've feel I've got a pretty good grasp of pH, alkalinity, and calcium and how they relate to each other. I have no problem being patient, but obviously don't want to risk the animals health either. <At this point immediate corrective measures are called for.> I have been all over your website FAQs on this subject; hard to tell though if I should let it ride or make changes. <Definitely make changes.> According to Knop directions, I'm supposed to adjust bubble rate until effluent pH is 6.5. When I do this, however, with a bubble rate of 20 or so, the tank kH rises overnight to 14 and Ca stays at 420-430. <Those figures are pretty good. Do they maintain or continue to increase? And what is the tank pH at that point?> When I back off the bubble rate to 15-17, kH falls about 0.7 per day, and effluent pH rises to about 7. It wouldn't surprise me if kH is around 10 when I get home tonight. I find it hard to believe the reactor is that sensitive. Having a hard time fine tuning, to say the least. Should I be adjusting my drip rate and if so what is the relationship between increasing/decreasing the drip rate to kH/Ca for a given bubble rate? <Probably best to concentrate on one variable right now else things could get very complicated.> Am I doing something wrong here? The previous owner used a bubble rate between 15-20 and he was reported to be rock steady at kH of 11 and Ca of 460. Any advice on the one-sided clam/tang boxing match? Tang is the boss of the tank by far, about 3.5 inches long and ready for a larger home. <I would consider removing one or the other. The nipping is detrimental to the clam as well as the constant closing (loosing light and the ability to photosynthesize energy).> One other factoid: I had a small BGA outbreak, and very reluctantly followed my LFS's advice and used Chemi-clean by Boyd Industries. The chemical was labeled as safe for all fish, corals, inverts, nitrifying bacteria, etc., which I didn't 100% believe. About three hours after dosing is when the clam retracted and the tang became aggressive the next day after. Coincidence or related? <Perhaps to the Clam's reaction but not directly to the Tang.> BGA is gone, did a 20% water change two days ago, and vowed to never use the stuff again. Any thoughts on Chemi-clean? <I have never used it, but I always refuse to use a product directed at the symptom instead of going after the cause. In this case, using a product to kill the BGA instead of eliminating the sources causing it to thrive.> Nothing else appeared to be phased by it....yet. I hoping time/dilution will bring my clam back to its former self. Agreed? Advice? <Not as long as it is being attacked/eaten.> Sorry for the long post. I've ordered your book and want to thank you for this highly-valued forum. Kind regards, Jim <Awaiting your reply to a few follow-up questions. -Steven Pro>

No CA reactor yet Hello I use a auto top system with 110 gals of reserve (2 big garbage cans) and a float switch. My question is can I add tribuffer and turbo calcium in this make up water ?  <not concurrently... just add buffer IMO> Or will be it become ineffective from sitting ? As of right now a teaspoon of TC per week keeps me at CA 400PPM ......Thanks again in advance!! <personally... I'm not thrilled with the Turbo Calcium (calcium chloride) for daily use in the long run. There are many concerns and complications (12+month picture) with accumulated chloride ions skewing the Ca/ALK dynamic. This product is good for a quick or emergent fix. I prefer Kalkwasser or a calcium reactor for daily supplementation. Kindly, Anthony>

Two-Part Calcium Additive Clarification Hi Jason C, Thanks for all the advice. The Kole tang is doing better now that he is on a normal light cycle. I had always heard that too much bright light at once was not good for the animals. <<it's my thinking that as long as there is a place to "escape to the shade" they can deal with these changes on their own terms. More important long-term to become and stay consistent with lighting.>> Also, I was wondering how I am using the buffer solution incorrectly. About two weeks ago I checked my alkalinity and calcium and they were both low (lights in main tank were on), so I began adding the two part buffer solution (one is for alkalinity and the other for calcium). They have both since gone up to acceptable levels. So I don't understand. I was definitely paranoid about pouring a chemical into my tank, so please tell me I don't have to anymore and how to keep my alkalinity up. By the way, I am not using Kalkwasser or any other additive. <<ok, my apologies for not being a little more clear. I think I had misunderstood your email and was really just trying to clarify that IF... one were using a two-part calcium product to strictly alter your alkalinity, that it would be a mis-use of the product. Sounds like you are using it correctly, and it is the best way to deal with boosting calcium in marine systems short of expensive equipment, certainly best for you and me. As far as adding chemicals, well... calcium does "go away" in marine systems and as such you need to get it back in somehow. Two-part calcium systems are not frivolous additives, or some magic elixir, but necessary for a healthy reef system.>> Jana <<Cheers, J -- >>

Do I need Calcium Supplements for Mushrooms? Mr. Fenner or Jason, <<JasonC here...>> Hi <<hello>> I email you earlier about converting my tank to a mushroom only tank. If I do this (according to Albert Thiel) I wont need calcium supplementation) anymore unless I keep stonies which I would not be. Is this true?? <<sounds good to me - if that were all you were keeping. If you wanted to promote coralline algae growth on your live rock, etc... you'd need to add calcium at some point. Cheers, J -- >>

Moved the Blenny, now tell me about Calcium again... Hi Steven, I am going to give the blenny to a neighbor who has a larger and more sparsely populated tank -- he is in a baby net until I can take him over tomorrow. A shame as he is cute, but I don't want to loose him and am pretty sure he would get pounded in the smaller tank. <Good to hear he will get a new home. Always good to have a lot of fishy friends.> Thanks for the heads up on the calcium and alkalinity. I run a remora pro skimmer during days, and use a canister magnum with a carbon change monthly, so I am leaning towards the other two as causes. I had not been monitoring either because I had originally been told by the LFS that if my pH was in line the alkalinity would be, <Not really. They are related, but not the exact same.> and using aragonite sand I shouldn't have to worry about calcium. <Sand will dissolve over time and add some extra calcium, but I tend to think of it as a happy surprise than trying to rely on it for all calcium.> It wasn't until I talked to the owner of the LFS that I was told to start dosing for calcium. My other corals have doubled in size when regarding the skeletal size -- the frogspawn went from a 2 branched frag to an 8 <Great to hear and why you really need to monitor and dose for calcium, when you have consumers such as these.> this one has gotten larger than it was when I got it, but it is certainly not performing the way it used to, so it is possible that the calcium is depleted, I would think. I will look over the website for some tips and see what I will need to purchase to monitor both correctly. (YEA -- another shopping trip!) <There are many manufacturers of test kits for calcium and alkalinity. I am currently using Saliferts and like their performance ad cost.> Thanks again for your time and assistance, Cari <You are quite welcome. I am glad to help. -Steven Pro>

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/Alkalinity Hello Wet Web Media Consortium , Never know who will respond to emails . I am still having a problem getting my calcium levels past 380 after about three weeks of dosing with Kent A and B solutions . All other parameters are within tolerances . I only have Live Rock in the tank with yellow tangs . The tank is a 120 with a large CPR wet/dry/protein skimmer . Any suggestions would be greatly appreciated. <Use a Calcium Chloride solution to raise your calcium levels and then maintain it with the two-part solutions.> Also I've noticed that your Alkalinity levels in FAQ are being measured in dKH , my test kit measures in meg/L . What is the correlation between the two? <2.8 x meq/l = dKH> Thanks for the help you guys provide thousands of enthusiasts around the world . Richard Atkinson <You are welcome. -Steven Pro>

Substrate I have 2 questions which will undoubtedly go in different places... I have a 37 gal Eclipse reef tank. I used to add Seachem's Reef Calcium to maintain Ca levels.  <Calcium gluconate (sugar calcium) is great for growing corallines, but very dubious for calcifying reef coral and invertebrates> In November I took my tank apart to put in a plenum, and used aragonite as part of my new substrate. After that my Ca level read 675!  <actually not likely/possible...a misreading for certain. You would have seen a crystalline precipitation long before you hit 600+> I stopped adding the Reef Ca, and it has since maintained a level of about 450. I assume this is from dissolution of aragonite?  <agreed, but please do reference your test kits against and other type. brand titration> Is it ok that I no longer add Reef Ca?  <possible, but confirm the validity first> Is the dissolved aragonite just as bio-available as the Ca additive?  <yes> (I have noticed that my coralline algae has not been growing very well, <exactly...above comments on gluconate> but my KH has been on the low side, about 8 or 9, for the past few months. Have been adding more buffer and Reef Carbonate and this is improving.) <wise...also use some Kalkwasser even if small amounts...many benefits> I also have a 20g FW tank of rummy noses. Its substrate is plain old white aquarium gravel from the LFS, nothing special. I have always used plain RO with no buffers in this tank, in an attempt to give them soft water. For some reason the GH of this tank is always 5-8. I have confirmed that the GH of my RO is in fact 0. Can this be coming from the gravel? Is there anything I can do about this? <nothing to do...you are lucky, straight R/O is rather dangerous and unstable if not tempered. Unless you are trying to breed the rummies... enjoy the nice balance> Thanks very much! I LOVE your website and your answers (spent 8 hours reading on it a couple of weekends ago, and I have many more questions, but these have been bothering me for a while!) <excellent///best of luck to you. Do be sure to pass along what you learn to others. Anthony Calfo> Tracy Creek

Re: Iodine dipping, calcium testing > Hello Robert, > <Anthony Calfo in your service> > I have been reading up on dipping corals in iodine before adding them to the tank but was wondering what the concentration of iodine is in Kent's Concentrated Iodine. The bottle states 22.5mg/oz. > <we do not know their "proprietary" concentration, but some aquarists believe that it is simply undiluted Lugol's solution of iodine> > How many drops per gallon would you recommend for a dip solution. > <undiluted Lugol's solution as a therapeutic dip can be applied at 1 drop per five gallons of bath water in a SEPARATE bucket/vessel for up to fifteen > minutes daily (strong aeration/circulation please).> > Also. My calcareous algae (Halimeda sp.) is growing only so, so. A lot of new growth but the older growth gradually turns a marbled white and then solid white. > <somewhat normal, but what is your alkalinity? And are your Ca and Buffer solutions dosed VERY consistently? If not, it can easily cause the growth/death cycle you have noted> My alkalinity is always quite high at 4.5-5 meq./liter without buffering. My Ph also is high at 8.4-8.5. An odd note. I only add Kalkwasser, somewhat erratically I might add, but with an Aquarium Systems Ca Test Kit the Ca level reads more than 550.  <honestly...this seems highly unlikely. I'm wondering if your readings are accurate. To have such high free calcium/alkalinity without a crystalline precipitation is very uncommon. Begin by taking a cup of aquarium water and ameliorating it with another cup of DI/RO water (calcium free)...(essentially diluting a sample of your tank water in half)... then test for calcium and double the reading that you get to see how close you come to the perceived 550ppm. I suspect that you will not get a match.> I don't know if that is because of the difficulty of distinguishing that dark purple from the "true blue" color you are supposed to achieve. I have two of the same kits and they read the same. Since then have been using the Red Sea Test which reads 400. <wow.. that is one heck of a discrepancy!> > My water parameters are very good with calcium levels according to Red Sea test at 400. I just ordered some iron/Mang additive and hope that will help. > My Dictyota algae on the other hand does quite well. Any ideas? > <Dictyota is lovely but can be a real nuisance unchecked... heavy handed iodine doses encourage its growth> > Thanks for your help. Craig > <best regards, Anthony>

Re: Iodine dipping, calcium Yes...the trick indeed is very consistent (daily) calcium dosing. A fast growing plant or coral has a similar or steadily growing daily demand for calcium. If, however, the availability of said calcium fluctuates wildly from abundant to minimal from day to day, then you get the strange growth/death spurts that you have observed. Anthony

Disappearing Ca and Bogus Test  Gents, <Only Bob and I... the rest of the crew actually work real jobs for a living <smile> Anthony> To answer your test kit doubts, I was using a SeaTest kit and have recently bought a Salifert. They agreed on the readings when I transitioned to the more accurate Salifert test. The cited values are from the Salifert kit. I'll try supplementing a small volume to see if I can get a higher reading. <Thank you.. and yes, interesting that it should take so much product and still barely influence the system... hard to believe> Also I have no stony corals, just one "red" open brain coral (Trachyphyllia). <all the more reason for the suspicion, this one stony coral is EXTREMELY slow at calcification> Only additive is the ESV two-part - I'm trying to be a minimalist. <I can appreciate that> With regard to a Ca snow storm, it's obvious when it occurs - precipitation as soon as the solution is added?  <absolutely.. a tragic marvel to behold> I've never seen it. Could it slowly plate out on your tank walls like a ghostly algae? <not so and still reflect the daily consumption of free calcium that you are reporting. And keep in mind... calcium doesn't just get sucked out of the system... calcium AND carbonate get sucked out to form calcite/aragonite/whatever... yet you aren't reporting the same severe difficulties with alkalinity. The calcium in my opinion isn't disappearing, it just isn't being reported accurately for some reason. Hehe... or it is, but your two-part mix is missing the calcium component...hehehe. The glass jar concentration test will tell you something> Thanks again! See you guys at a San Diego meeting sometime soon. <it would be my pleasure! Is it true that SDMAS has dancing girls after every meeting <wink>? Anthony Calfo> David

Help - Cyanobacteria (maybe), Calcium...and more Calcium Hi again, <greetings> I have been reading about Calcium supplementation on your web site and have a few questions. I currently can not afford a calcium reactor.  <a fantastic device... do look into building your own... quite simple and there are many good DIY sites on the Web. Start with the DIY link on www.ozreef.org> I am using Kent Marine "Pro-Buffer dKH" and "Liquid Calcium". The problem I have it that I can not get the calcium level over 300 and the pH stays pegged at 8.0-8.1. I would like to get the calcium higher and get the pH up to about 8.3. <before you go any further. take a glass of aquarium water, test the pH, then aerate it heavily overnight and test it again. If the pH rises, you have a problem with gas exchange that must be taken care of first> I know you are reluctant to recommend Kalkwasser. <Bob, may be... but I am not. I wouldn't take calcium chloride for free...if you use enough of it, chlorides build and you eventually have a problem maintaining alkalinity/pH...hmmmm, sound familiar? I love Kalkwasser when it is dosed properly (add enough to raise your pH by no more than .1> My questions is, what do you think about Craig Bingham's suggestion of adding white vinegar to the water before mixing in the Kalk? Please be specific since I have not seen you mention this idea on your Kalk FAQ. <Neither Bob nor I have personal experience with this new technique> If you don't like this idea, how then would you suggest I get the calcium and pH up in my reef tank? FYI, the tank has a 3" aragonite sand bed, and a sump with Caulerpa and 24x7 lights on (in sump only). <confirm your readings on other test kits first. Then dilute the obvious imbalance in the tank with some larger water changes with an enriched sea salt (I'm happy with reef crystals). Be patient with the weak pH and alkalinity for a few weeks and only use a two part supplement (AFTER the water changes through dilution have balanced Ca and carbonates, even if still low) to gradually raise the levels back to par. It will work. But the tank MUST be diluted first. And the readings are not going to return to normal the first night that you use the two- part (B-Ionic) supplement. It will a take some weeks. But it will be more natural and gradual. Have faith. Anthony> Thanks again, Jay Schudel

Calcium, Anxious Reefer Hi Bob, <Anthony Calfo here, bud> I hope you can lend some advice. I'm having difficulty keeping the Ca levels elevated enough in my tank. The spec's are as follows: Approx 65-70 gal system capacity, Approx 40 lbs LR, plus an additional ~12 lbs dead rock <you likely will need more rock if the tank goes full reef and depends on LR as primary filtration...otherwise too modest> 45lbs aragonite <sugar fine grade I hope, or keep up with siphoning from excess sediments> Well water fresh is KH=14, PH=8.4, Ca=340 Instant Ocean salt SG=1.024 <fair enough> At first (this system. is only 3 weeks old) I was using CaCl to boost the calcium, but stopped due to concerns of excessive Cl in the system (it took a lot of CaCl to even begin to raise the Ca.) <whoa, but... a three week old tank. Sounds like a bit of a knee jerk reaction for such a young tank. Let things settle in a bit, my friend. True though about the CaCl imbalance... however, use it only when you have an imbalance (deficiency of calcium) in relation to alkalinity. You however have nicely balanced source water... just use a two-part mix> Now I'm using ESV Bi-Ionic.  <Ah-ha!> The instructions say to add only up tsp. 1ml per gal per day. If I do this the Ca level hovers around 340.  <assuming your test kit is correct...have you used another brand to confirm?> I have experimented with dosages (there is a 4" yellow tang and two cleaner shrimps in there--they're doing OK) of up to 120 ml dosed 3x daily--this keeps the Ca up around 400. The coralline algae seem to look more vibrant at this level, but this is SIX TIMES the rec. dose!!! <with all due respect, you couldn't tell this in a three week old tank. I have seen a lot of aquarists in more than a decade kill much livestock and fail from such excessive and obsessive manipulating of water quality... you need to relax, my friend. Aquariology should be peaceful and low maintenance if you are doing it right> I have gotten conflicting advice from local reef shops. One says that it's OK because the calcium is being utilized,  <not in a tank that is three weeks old... you couldn't possibly track a net daily deficit of calcium on a home-grade test kit in a three week old tank. That advice was simply inaccurate> that I should just keep on dosing like this (though I have gone through almost a quart of the stuff in a week!).  <I'd tell you that to if I was a sales person and saw a cash cow like you...hehe. Just kidding, bud... on all counts> Another says to only dose as per instructions and wait for the level to rise over several months  <agreed... very prudent advice... I like this counsel better> though I can't see how this would happen....if I slow the doses the Ca drops from 400 to like 350 in a matter of hours!). <assuming your kit or reading is even accurate. Dude, you could have 50 stony corals in your tank and at three weeks old (stressed/weak/no growth) there still could not be a demand of 50ppm of calcium daily, let alone within hours. Fact: you are not getting accurate readings> I have read on another reef page to dose with one product to initially raise calcium levels (Kent Liquid Calcium?),  <chloride...don't bother> then maintain it with the two-part buffers.  <except your calcium is not proportionately low!!! your alkalinity, calcium and pH are each a whisker low but amendable with a two part mix> I haven't tried this yet.... Please any advice here would be helpful. Am I missing something? It seems it shouldn't be so difficult! THANK YOU VERY MUCH! Erik Nelson <Erik... do listen to some soothing orchestral music (Beethoven Symphony 8, 2nd movement perhaps) and relax... your tank hasn't even gathered dust yet. Everything good and bad should happen slowly in your tank if you are doing it correctly. Look into some good books and take your time. O-tay? Anthony>

Disappearing Calcium or Bogus Test kit? Guys,  <Cheerio> The recurring calcium question.  <you said it, brother!> I have a 100gal FO tank with ~400watts of VHO lighting. I want to add more zooxanthellae and SPS in the future. At this juncture I want to control the alkalinity and calcium before taking the next step. <wise> I am using ESV's 2 part solution and my current readings are 13 dKH and 200ppm.  <the alkalinity is fine, but the calcium is implausible unless you had a snowstorm (crystalline precipitate of calcium)... do check you readings against two other types/brands of test kit. Without a precipitous event, that reading is nearly impossible in the real world, all things considered> I starting by adding the manufacturers recommended amounts and didn't reach anywhere near 400ppm Ca; I never exceeded 200 ppm.  <all the more unlikely... confirm by adding a high dose to a glass of aquarium water and testing that concentrated sample with your dubious test kit. If you can't move the sample reading, you definitely have a problem with the test kit and may still have, even if so> I have since eliminated the Halimeda shrub (basketball size) which seems to act like a calcium filter.  <there is no way that your Halimeda is drawing so much calcium that it could temper a reading by 200ppm!!! Do you have many stony corals too?> I am down to several small plants. How aggressive can I be with the 2-part elixir - the manufacturer says not to exceed 100ml in a 24hr period?  <are you monitoring pH as you add this dose... you really must be careful> This maximum dose seems silly because it's really a function of how big the tank is.  <not true, sir... the tank size is irrelevant... it is the net daily demand for free calcium and carbonates that is relevant. So a 50 gallon tank with 20 stony corals is going to require more supplementation than a swimming pool full of mushroom corallimorph...er, you get the point> I've increased the dose of the Ca part to twice the dose 2 times a day. The pH is fine (8.6 at end of day), no Ca snow and the remaining Halimeda are showing great growth (Ca filtering again).  <still not 200ppm> Is there another way to get it up to normal levels? I like the Halimeda and don't want to eliminate it. <you definitely do not have to... Halimeda do draw, but are used as indicators of good/consistent calcium levels...they can't easily out compete every other draw to exclusion however> One more question, please? I have 2 kinds of Halimeda. One is the common coin shaped, cactus type. The other I want to identify. It is much finer in structure and branches more. I've yet to see a picture of it in my Google searches. Any idea? <absolutely... please refer to Marine Plants of the Caribbean for a likely match... and get some new kits (you aren't using liquid sugar based calcium in addition to the two-part, by chance were you? Skewing the readings...letting you think you are low)> Thanks for your generous contribution to the hobby! David A. Bidwell <my pleasure...>

CALCIUM Dear Mr. Fenner, <You got Steven Pro tonight.> I have a question regarding my calcium levels . I can't seem to get over 350 using the two part Kent regimen everyday for the last two weeks. My magnesium is at about 1400 and the alkalinity is around 5.0 . I do not have any corals in the tank yet , but I do have approx. 100 lbs. of live rock . The tank is a 120 gallon , running a large CPR wet/dry with protein skimming . What am I doing wrong . Thank You , Richard Atkinson <If you are measuring alkalinity in dKH, then that too seem a little low and I would simply increase the amount of two-part solution you are adding. That is the major drawback of the two-part solutions, cost. Adding enough to keep a fairly large tank in the appropriate ranges can get expensive fast. You may want to look into Calcium Reactors. -Steven Pro>

Adding Buffer or Calcium? Anthony, <Cheers, John> Thanks for the clarification. Only problem is that I too have a reef system albeit a small load right now of a Pinked Tip Anemone, Hammer coral, feather duster, serpents star, star fishes etc. and about 90 lbs of live rock. Everything is doing quite well, but maybe I should not do the baking soda thing? <really two different things and purposes. Baking soda is largely for increasing pH (tweaking pH in an otherwise normal/healthy tank with other buffers/carbonates as one gets from med/hard tap water). It is easy to use and monitor. If that is your primary goal and you are using tap water (not demineralized R/O or DI water) than please use the baking soda at the prescribed CMA dose. If however, an aquarist IS using purified water (lacking buffers) and/or has a known deficiency in alkalinity in the water (naturally soft tap water for example) then sodium bicarbonate alone will not serve a reefkeeper well. Most commercial buffers (like Aquarium Systems Seabuffer) are "tri-buffers" (borate, carbonate and admittedly mostly bicarbonate) and better suited for increasing and maintaining pH (from the baking soda) as well as ALKALINITY (the buffering ability of water). If you haven't had the displeasure <smile> yet of studying the difference between pH and Alkalinity, then this may be part of the confusion. Back to the "story"... reef aquarists generally want/need to put buffers AND calcium into their system and neither one alone (baking soda or Kalkwasser) will usually do the trick. I hope this hasn't confused matters further. Please do follow up if you need clarification. Nonetheless... the bottom line is that hard tap water may not need to be buffered, and baking soda will give you the extra pH you need... and purified water is not buffered, and needs something more than just bicarbonate. Kind regards, Anthony> John

Calcium Hello Bob- <Anthony Calfo here while Bob models for a modern day interpretive sculpture of "The Thinker" called "Bob-onna-Loo"> Could you please give an opinion here? Tank: 50g w 30#LR + 15#DR, no sand yet (set up only 11/2 weeks ago) H2O from well spigot: ozone'd hard (KH=12, Ca=~300, PH=8.4) H20 in tank: very hard (KH=18+, Ca=~320, PH=8.8 w/ Red Sea Salt) <for starters... your source water is enviable. Perhaps try regular Instant Ocean Sea Salt to have a more acceptable range of chemistry on mixing> What is your advice as to the best way to raise Ca in this system? LFS says no to 2 part buffers as the CaCO3 is already too high.... they recommend CaCl. <agreed and fine for the temporary correct of low calcium so that you can resume 2-part supplements> They say this will also lower the PH over time as well (as it is too high), <a bad habit to use CaCl continuously for far to many reasons to list here. Trust me... CaCl is a temporary fix> but it is taking a lot of this stuff to raise the Ca up noticeably--like 2 tablespoons already and still going. I'm worried about too much Cl in here! What do you recommend? <Dilution in time will temper it. Do try regular Instant Ocean sea salt which may be more appropriate for your source water> Also, once the sand is in place and the biological processes are in swing, do you think the Ca levels will naturally be more acceptable/more stable? <so complex...not so literal, but perhaps> Thank you so much! Erik Nelson <very kind regards, Anthony>

pH, CO2 and Calcium Reactor hi bob i need to ask a question <Todd, Anthony Calfo here in your service while Bob counts how many jelly beans will fit into his navel in anticipation of a super bowl party bet> i use a calcium reactor on my 150 gallon tank lately the ph goes at 7.7 in the morning to7.9 high in the day <scary low indeed> i use a ph probe witch calibrate once a week am i getting to much co2 in the tank <possible, but not the only explanation... aerate a glass of water from the aquarium to see if the pH rises significantly. You may simply need to have better aeration in the display (although never aerate the sump where the reactor effluent drops)... although not likely the case. If you had excess CO2 overtime you might notice an increase in nuisance microalgae growth> and if so should i shut off the co2 let the ph rise and then continue the co2 <never make such drastic moves... good and bad things should happen slow in an aquarium. Is your effluent adjusted properly (slow drip/bubble counter coordinated?> if i do shut the co2 off i do notice the tanks ph starts to rise i keep the reactor at 6.4 ph thank you bob Todd from new York <another solution is to have a second reactor full of media inline to boost the pH on the outflow. Very effective and perhaps your best solution. Becoming the standard. Anthony>

High Alkalinity and Calcium Yep...test kits were bogus Anthony, <Greetings fellow blueberry eater> Thanks for your response. i had my water tested today by one of the local dealers with completely different testing equipment and the results are as follows. Ca 560, PH 8.0, Mg 1900, ALK 7meq/l . i guess the test kits i have are worthless. What do you suggest for remedies? <yes... not a surprise from the previous numbers reported. The solution is not crystal clear considering the complexity of balance with dissolved organics in seawater. However. step by step, we know that your calcium is artificially and dangerously high, and that the pH is rather low. Alkalinity is not terrible, but a bit on the low side as well. Lets begin with a relaxation on calcium supplementation and enough dilution from water change's) to bring your calcium closer to 400. When water changes get your readings for calcium between 380 and 425 ppm, and alkalinity between 8-12dkh...start using a two part liquid calcium/Alk supplement as per directions. In most cases you should be able to resume a more traditional chemistry. Wane off of the two part if you prefer dosing separately. But know that the 2-part mixes are quite ideal for balance and their only disadvantage is price <smile>.Don't worry about the pH during the process too much... it should fall into place naturally with the correction. Best regards, Anthony> Chris

Re: High Alkalinity and Calcium Anthony, Thanks for your expertise, I will follow your directions as noted... however you said that 7meq/l was low? was that correct? isn't that like 19.5 dKH? <Ahhh, my apologies good sir.... I read through that part of your last e-mail too fast and thought the reference was already to dKH. Indeed, you are not at all low...but rather a bit high! Thank you for keeping me on my toes <G>> ONCE AGAIN THANKS!!! CHRIS <my pleasure. With kind regards, Anthony>

Two Part Calcium Applications Hi Mr. Fenner, <Boon Keong... Anthony Calfo here, answering Bob's mail while he is away> First of all, thank you for reading my e-mail. I have a few questions about my 20 gallon reef tank. I have been dosing the tank with Kent Marine Tech A and B for the past few weeks to raise my alkalinity and calcium. <two part mixes...generally very good and reliable calcium/alkalinity supplements even when not cost effective> I started out with a very conservative dosage and gradually moved up to the maximum dosage for the tank. <way to go> Each time when I dosed with a particular amount of Kent Marine, the calcium and alkalinity would rise. I would stick with the same dosage for about a week, and the readings would stay the same. So then I would increased the dosage, and the readings would go up. <balanced movement... working as designed> I am now at the maximum recommended dosage and my readings are still not on target. <"not on target" relative to what? What is your goal? Maintenance or growth? In some ways, the high levels of Calcium and Alkalinity that you may read as recommended are mutually exclusive (not simultaneously possible). Temporarily hold off on the two part mix, if you like... then raise one of the targeted parameters singularly (as with calcium chloride for calcium levels) and then resume the two part mix and you will be fine> My alkalinity is about 2.6 meq/L and my calcium is about 300 ppm.  <not ideal, nor unreasonable> The question is it safe to go over the recommended maximum dosage for the tank?  <not recommended or necessary... follow above advice if you want a higher level> All other parameters are on target. Thanks in advance for your help. <Best of luck in your endeavors...Anthony> Boon

Treating your tank with Calcium  I wonder if you could answer a question for me, (since I've had different answers from various aquarium stores). I have a 90 gallon reef tank. I'm using Tropic Marine Calcium (powder form). Does it make a difference if I sprinkle the calcium over the top of the water or if I mix it with salt water them pour the content into the tank?  <It/this does make a difference. I would definitely pre-dissolve this product (and all like it) and administer in solution... slowly, in an area of rapid water movement (like near a powerhead discharge)> Tropic marine tells us to sprinkle it. However it also mentions not to let the calcium land on any livestock. That's a little hard to do since I have several star fish.  <Agreed> They move under rocks and hide when I add the calcium. (especially the sand shifters). I've had star fish lose legs in the past. Any relation?  <Possibly... the material is quite caustic (basic in pH)... burns on contact...> Would mixing it first be better?  <Absolutely... Am very surprised at the instructions from Tropic Marin here (have recently helped with transliteration of some instructions for Knop Products from Germany... fully realize how "things get lost, changed")... Tropic Marin is a great company. Will send this msg. and response to their attention.> I was told it changes the chemical reaction if I do that. I would appreciate your help. <No change that is appreciable. Bob Fenner, WetWebMedia.com who is a not-so-old ex High School Chemistry and Physics teacher> Regards, Bruno Matteo

Halimeda and Calcium Happy Holidays! Through help from your website I feel I have made great progress in understanding the chemistry of my tank. Lately I have been trying to get a grip on the CO2, bicarbonate, buffering action which is a very interesting dance.  <Well put> I purchased alkalinity and Ca test kits to see where the tank is situated in the continuum. <Ah, even better> My alkalinity was a paltry 80 which I subsequently boosted to 180ish with NA bicarb. The Ca was dreadfully low too at about 150 ppm. Subsequently I purchased ESV 2 part solutions to try and boost the Ca. I add it in the mornings as directed. It has been about 3 weeks and the concentration hasn't budged. I believe the reason is the calcareous algae. <Likely> I have a 100gal tank with a generous (2-3 cu ft volume) amount of Halimeda. I believe it is absorbing it soon after it becomes available. I don't believe it's precipitating but my pH does reach 8.4-8.6 by the end of the day. How would one know if it's precipitating? <Mmm, you would likely see (yes, that much) the "powder" on the surface of your substrate, rock...> Short of buying a coral dissolver (Ca reactor) I believe my best courses of action would be to cut back the Halimeda and/or increase the supplement and watch the parameters. <Yes... I would try a bit of both> I'd prefer the former over the latter. What would you suggest? The only other consumer of Ca is a Trachyphyllia geoffroyi. It's been in the tank 2 months and seems content. Should I be concerned about its well-being under chronically low Ca concentrations? <Not so much... it has adapted well-enough to your conditions... and has other mechanisms for utilizing food, alkaline and biomineral sources (the last two from other than the water)> P.S. I've gone night diving in my tank! I mean after the lights have gone off and I am feeding the Trachyphyllia geoffroyi the night critters come out. It's a whole different perspective that I recommend others to try. Thanks again and Happy New Year!! <Yes! Be chatting my friend. Bob Fenner> David A. Bidwell

Sick feather duster fan worm and calcium questions Hi, hope you're doing well and have a happy holiday season! I 've had a feather duster for about a week and it seems very sick. The last half of it's tube ( distal end where it's attached to rock) is turning black, soft, and ugly --was originally all a uniform gray and quite hard.  Also it no longer retracts the fan when approached or touched. I plan to take it back to LFS to see what they think, but I trust your opinion more...any ideas?  <Not good... dead or dying...> My system: 46 with 70 # LR, 60 # aragonite, Eheim, CPR BakPak, one MJ powerhead. Temp-77, SG 1023-1024, AMMONIA, nitrites, and nitrates all zero, Calcium 300(red sea) and 340(hagen), pH 8.2-8.4, and alk approx 3.2(red sea; I have a hard time with the color comparison and may try a different brand test kit). Livestock - one fan worm , scarlet hermits, snails, 5 soft corals, and one bubble coral> BTW, the bubble sometimes seems a little shriveled up for sev. hrs to a day or so then seems fully distended and fine again. Is this variability normal? <Yes> I've had it about two weeks; it's about 8" below two 96 watt PCs (one blue one on 14 hrs/day; one 10,000K daylite on 12 hrs/day ). It's fairly close to the return from the Eheim, so the bubbles are in constant motion that doesn't seem too violent to me , but I have nothing by which to judge how much flow is ok. When it's shrunken, it's also sort of beige instead of the usual pure white. Sound OK? <Yes, typical> The calcium question is what's the best way to get it up to 400-450. <A working calcium reactor> I'm using C-balance(2 part) and did a 10% h20 change but it 's staying low. How does one know whether to just use more of the C-balance I'm not up to the max dose), or to add a Ca supplement? <Need to have records... one way, of alkalinity changes with addition of part 2 here... if not depressing alkalinity, can add more part 2> Should the 2-part supplement always be used in equal amounts? <Not always... depends on readings for calcium/biominerals and alkalinity, desires, livestock...> I've read the site but can't seem to find an answer there. Thanks as always for your help;; I hate to think what it would be like to get started in this hobby without your guidance. Happy New Year! PS Just called the LFS re the fan worm and they were very uninterested in even looking at it! <I'll bet.> I'm is the SF bay area and can't believe the shortage of decent marine stores! any recommendations in my area? maybe I just haven't found the best ones. <Nippon Goldfish (not just goldfish as you will see.). Bob Fenner> Re: Sick feather duster fan worm and calcium questions Thanks for instant response! very much appreciated!!. Nippon was the store in question, I'm afraid; <Yikes... do you know Steve there?> lately they've seemed very unhelpful and their livestock looks pathetic, except for this one feather duster which was beautiful in their tank and now may be dying. Actually the back half of its tube is more greenish and almost translucent, not really black and its fan is waving and looking fine.  <Oh! Then do just leave it in place...> If it is dying , does it sound like I've done anything to kill it? I don't want to get more if so till I figure it out. About the calcium: like so many of your ;;correspondents, I'm trying to get by without another expensive piece of gear, for now anyway. I'm unclear what kind of records you're referring to. <The tests you do for the qualities in question... do you keep a journal of when, what was observed?> My Ca levels have been about 300-350 all along;; pH seems to be slowly drifting down from 8.4 to 8.2; Alk also drifting down from 3.6 to 3.2-3.4; have been using 15 ml of each of the 2-part C-balance daily or almost daily). I tested the Ca in my QT tank which is empty and it's also in the 300-350 range. What should it be in newly made up SW with Instant Ocean?  <If memory serves closer to 400... their (Aquarium Systems) reef salt mix is even more artificially boosted> As long as I test the parameters, is there any reason not to experiment with going up to the max dose on the C-Balance and also adding a pure Ca supplement?  <Not really. Just take your time.> There are so many brands out there... any recommendations on either brand or type( chloride, hydroxide, lid, solid, etc)? Thanks again! <Stick with one manufacturer's line unless you know exactly the chemical composition of the materials you're using, and their interactions. Bob Fenner>

Re: Sick feather duster fan worm and calcium questions Hi, again, just checked the KNOP website to learn more about the Ca reactors and it seems you need a sump to use one; <Mmm, not so... can discharge directly into systems> I forget to mention that I'm sumpless...if I don't have clams or lots of hard corals what's a minimum acceptable Ca level, anyway? Isn't the ocean about 380? <Please read over the calcium and related sections posted on WetWebMedia.com Bob Fenner>