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FAQs on Calcium Reactors, Rationale, Use

Related Articles: Calcium Reactors and How They Work by James Gasta, Calcium Reactors: The Top 10 (Plus) Frequently Asked Questions about Calcium Reactors by Jason Chodakowski, Calcium, Understanding Calcium & Alkalinity, Kalkwasser, Calcium Reactors

Related FAQs: Calcium Reactors 1Calcium Reactors 2Calcium Reactors 3Calcium Reactors 4, Calcium Reactors 5, & FAQs on Calcium Reactors: Selection, Installation, Operation, Media, Measuring, Trouble-Shooting, By Makes/Models, & Calcium and Alkalinity,  & FAQs on: The Science of Calcium & Alkalinity, Importance, Measure, Sources, Use of AdditivesTroubleshooting/Fixing, Products,

For most all large/r hobbyist, culture facilities, wholesale operations, there is no simpler, easier, less expensive means of supplying biomineral, alkalinity and pH stability and optimization than by Calcium Reactor use. Is it absolutely necessary? No.

Calcium Reactor Info 3/26/08 Hey there guys. I am debating on whether to get a calcium reactor and I cannot find any information on calcium reactors on your site. <There is indeed plenty.> My Calcium and alkalinity are always low and no buffer ever seems to do the trick. My question is could a calcium reactor be a bad thing? <Not anymore so than any other Ca/Alk supplementation.> Could it sky rocket my PH or add phosphates or things? <Not when tuned properly, again all the negative things that can happen with a Ca reactor can happen with supplements too.> Thanks guys, Jay <Welcome, a link to reactor info below, Scott V.> http://www.wetwebmedia.com/calcreactors.htm

Calcium in the Tank  -- 4/28/07 Hello WWM Crew!  I have just one question for you.  I have a 90 gallon reef tank at home.  It has been doing well over the course of the last three months since I got rid of my sump and added a 25 gallon refugium.  Made all the difference in the world (I have written to you before concerning my refugium and its success).  Here is the list of corals I have: 1X Cat's Paw SPS 4 X various moons polyp/zoanthid corals 1 X Pulsating Xenia 1 X Trumpet coral 2 X Colt corals 1 X purple Gorgonia I have many invertebrates and a T. Crocea clam as well.  I am starting to notice a decline in my calcium of about 10-20 ppm every day.  I try to keep the Ca at about 400ppm.  With all the corals I have in the tank, is this rate of calcium decline normal? <Not unusual, or not to be unexpected...> Everything is growing fine (some faster than others).  Water parameters are as follows: Ammonia: 0 Nitrites: 0 Nitrates: 0 Ph: 8.3 Alkalinity: 10dKh Salinity 1.022 I have spoken to people at different LFS's.  Some say they don't really add calcium to reef tanks but once a week and only see a minimal decline. <Mmm, such loss of Ca is dependent on a few principal factors... the overall metabolism of all the biomineralizing life in the systems... presence of other chemical species...> Others say they have to add calcium just about every day.  I am adding it about every other day to bring it up about 20ppm to stay around 400ppm.  Am I good to go? <Highly likely so> I am just being cautious because I am just starting to add hard corals for the first time.  I have been rather successful with the soft corals (after reading our site). R/ Jeff <Do give the Calcium articles and FAQs files a going over on WWM... Bob Fenner>

Calcium Reactors/Kalkwasser Reactors Hey Crew, <Ron> Happy Holidays! <And to you and yours> My 50 Gallon SPS reef tank is doing well.  I dose B Ionic 2 part DAILY!!  I drip ESV Kalk nightly for evaporated water... This has been becoming difficult, as I am a touring musician. <Yikes... perhaps a controller, automated dosing gear...> Should I get a reactor or Kalk reactor on such a small reef tank, or can you suggest other options so as to minimize the daily maintenance to the system??? <The best would be a simple reactor... a small Knop unit would be my first choice, but a local hobbyist/marine club may have an upcoming workshop where you could fashion your own> Thanks for your time. Also, SPS doing ok, but growing slowly. I understand many factors are involved.  Besides water motion/quality, lighting, what else helps?? <Many other factors...> Feeding? <Of a certainty, yes> if I feed,, I get phosphates and brown stuff on the sand.  My Phosphates are generally around .03-.04... Thanks! Jennifer NYC <Do try the feeding, extending your light period, vitamin and iodine/ide additions. Bob Fenner>

Calcium and SPS 11/01/06 Hi crew, <Hello> What will best meet the calcium demands in a SPS setup, a Kalk reactor or calcium reactor? Thanks Mohamed <Hands down a calcium reactor.  It is not so much the calcium, but more so the alkalinity.  SPS can have perfect calcium, but without the proper alkalinity levels, they cannot utilize the calcium.  Kalk doesn't raise calcium in a system, but rather maintains it.  Over time, Kalkwasser will begin to drive the alkalinity levels down, thus defeating the purpose.  I'm not saying it can't be done with Kalk, but it is not the best route to go in my opinion.  Cheers! -- Dr. J>

- Calcium Reactor Questions - Greetings    <Good morning to you - JasonC here...> My restlessness is on the reactors of calcium.       ¿Is it true that you/they are exclusive for aquariums with hard corals? <Not really - there are other mechanisms for supplementing calcium in a reef aquarium. That being said, a calcium reactor is probably the best way to supplement calcium, but does represent an investment in equipment.> My aquarium belongs to a mixed population in its majority soft corals (15) and some few hard (6) The soft corals don't benefit in (! anything!) of a reactor? <Untrue - soft corals do have calcium in their bodies, and do benefit from the addition of calcium.>   Do I have understood that a reactor "no" alone it produces calcium. <Calcium reactors add calcium and increase carbonate hardness in the system - both very useful for reef aquaria.> Ahead of time I give them thank you for the attention and the orientation that can give me    Greetings    Gsoler    PD. Excuse the translation but I am not very I practice with English <Your English is very much better than my Spanish. Cheers, J -- >

<Kalkwasser Reactor vs. Calcium Reactor> Hello all, hope things are going well. I am looking into purchasing a calcium reactor and have been reading the different FAQ's on your site. During other research I have been reading about < http://www.aqua-web.org/users/ealex/calcium/> Kalkwasser Reactors, any experience with these? <Not directly...> In your opinion is one better than the other? <In my opinion, yes - the calcium reactor would require less maintenance.> Did not see anything being discussed on your site about these. <There will be now.> I want to try to eliminate the need for daily Kalk/buff dosing so I really want to make the correct purchase. As always thanks for your suggestions <Go with the calcium reactor. Cheers, J -- >

- Ca & Alk, Calcium Reactor - Hello again and thanks for all the past help. My system has been running at pH 8.2, Ca 320ppm and Alk 10-11dKH since installing calcium reactor three months ago. I have tried to increase Ca by increasing bubble count to 120/min (started at 60) while keeping flow constant at manufacture's recommended starting point of 2-3l/hr. Effluent is close to ph 6.5 and 40 dKH. Trend seems to be that as I increase bubble count, alk increases but not Ca. I understand that Ca is necessarily lower when alk is high. Is this just a function of reactor media (ARM) and will I have to supplement Ca or will I eventually be able to dial in Ca to 350-400ppm with the right combination of CO2 and flow. <Well, two things come to mind - first, the ARM media is notoriously impure, which means you really can't rely on it for consistent results. Second, calcium reactors are 'really' alkalinity reactors, and by boosting alkalinity promote better availability of calcium - of course it helps that the effluent is calcium carbonate, but really, I don't see anything wrong with those numbers. Do also use the growth of your calcium consuming organisms as a guide.> Perhaps I need different media (suggestions?), <Knop Korallith.> or is 320ppm & 11dKH just fine and I should leave it alone? <Yes to that as well.> A. yongei frag is doing well so far but want to get everything right before starting to stock in earnest. Regards, George. <Cheers, J -- >

- Calcium Reactor Question - Hello Coral Oracles - Another mundane question. I am in the process of planning out my new 265 gal reef tank. Upgrade from a 110. I am considering adding a calcium reactor to the new system. I am currently using the B-Ionic 2 part system with satisfaction. I would like to see more growth in my Acro's but maybe its a timing thing. Anyways, what is your opinion on one vs. the other? <A calcium reactor is a fabulous investment. You will 'buy' a reactor's worth of calcium supplements if you continue the way you are going. Not to dis ESV, as their product is very good, but you have to dose and dose and dose and... buy more bottles and so on.> Is the calcium reactor worth the cost? <Absolutely - once the cost of procuring one is past, your only reoccurring costs are the CO2 and the media and neither of these is changed very often.> Thanks for your help (again)... <Cheers, J -- >

Calcium Reactor Not Required?   <Hey there, Scott F. here with you tonight.> I have a 400 watt 10k bulb on with a spider reflector, metal halide lighting setup. My question is how can I keep Acropora hard corals in it without a calcium reactor? <How?  By regular additions of calcium in the form of Kalkwasser or two part Calcium\Alkalinity additives such as B-Ionic, or C-Balance, etc.  Yes, a calcium reactor is more convenient with some respects but wonderful reef systems can be maintained with calcium supplementation as outlined above.> If so, what can I start out with that's not too demanding as far as Acropora goes? Are there any easy SPS that will thrive under these conditions? <There are many species that will fill the bill.  I highly advise that you purchase a good coral reference such as Eric Borneman's "Aquarium Corals" or Anthony Calfo's "Book of Coral Propagation.> I just want clams and SPS corals. Can I get away without purchasing a calcium reactor? <Sure, as I already mentioned above.> In dire need, Carlos, in Salinas, California. <Good luck Carlos, and happy reefing!  Regards, Scott F.>

Using a calcium reactor Hello, <Hi there> I get my saltwater from a research lab pumping it out of the sea here in Cape Town. However it is very low in alkalinity so I am continually adding loads of buffer.  My tank is 400 gallons with fish and live rock, no coral. Does a calcium reactor keep the alkalinity high meaning I don't need to add buffer or is it for something completely different?  Please forgive my ignorance. Many Thanks James. <It is my opinion that for especially larger "reef" systems with much in the way of biomineralizing life, there is no way better to assure/supply alkaline reserve, steady pH and alkaline earth elements (calcium, strontium, magnesium) than the use of a calcium reactor. Bob Fenner>

Calcium reactor question Gentlemen, Sorry to bother you, but I have a basic question regarding calcium reactors..... <That's why were here Jason, No problemo!> Are they a needed component for a successful marine tank? <Nope> Although the idea of them seems very handy, I'm not sure I want to part with $1000.00 unless I have to. I have a 92 gallon marine tank, with MH/Actinic lighting, a big sump, BakPak skimmer, and about 60lbs of live rock, with an aragonite/carbonate sand base. I periodically add trace elements (strontium, Iodine) and add Kalkwasser about three times a week (works out to about 6L a week, adding 2L at a time). My Calcium is about 400ppm and alkalinity 11Dkh. (I'm sure those were the numbers. I'm at work right now, so am not positive. If they seem out of whack, I assure you they were in the recommend range for a reef tank). Anyway, I have some cool fish, but have never really been able to keep extensive inverts (shrimps, snails, anenomes, and coral). Ammonia, Nitrate are 0. The only reason I can come up with to explain my lack of invert keeping ability is water quality/chemistry. I use RO water in my water changes at 15% a month. So that leaves Chemistry. Am I being sloppy with my supplements? are they that important? Will a reactor help me get the tank I have always wanted? I am thinking about getting a Marine Precision reactor. Any comments you have would be appreciated. Thanks Jason Nycz Calgary <You can buy a heck of a lot of carbonate/alkalinity supplements and hydrated lime/pickling lime/Kalkwasser mix for $1000. To keep inverts I would look to several things. One, a bigger, more efficient skimmer. You're pushing it with a Bak pak on a 92. Check out skimmers at some of the WetWebMedia.com sponsors, they make this all possible! Two is your water and how you supplement and top off. This needs to be "seamless" and less abrupt. Also, your R/O top off should be aerated and then buffered to 8.3 and heated to match your main. The Kalk should be dripped at night and averaged so it is dripped with replacement/top off each night, not three times a week. The three times a week deal can/is/will contribute to inconsistent pH, alk and calcium, but the biggee is a wandering pH. Kalk is something like 12pH, so it must be dripped slowly and consistently each late night until lights on in the AM. As far as your supplements, please test before using supplements. They can be the problem if used indiscriminately. So, the answer is, no you don't need to have a reactor. If you don't like to hassle setting up your top off and regular supplements, (with the exception of iodine) and you want really consistent water parameters, then a reactor might be for you. Check out the Knop reactors at Di's Aquatics at http://www.disaquatics.com/Merchant2/merchant.mv?Screen=PROD&Store_Code= DA&Product_Code=TCMAS  if you decide to go that route. Craig> 
Re: Calcium reactor question
Bob, Thanks very much for the comments. They are appreciated. I guess my conclusion is that on order to save time (and eventually money) a reactor could be the way to go. <Yes... a hoot responding... and sent off your query and my resp. to Jas.C> After buying all needed test kits, and continual supplements (in Canada, a bottle of strontium which lasts 2 weeks is $20), <Outrageous! Get together with some other hobbyists and buy the smallest whatever grade of strontium chloride from a chemical supply house...> I can see how the break even point on a reactor is not too far off. Without the reactor, it's obvious I need to have better Kalk dosing and water monitoring, which for me, raises it's own set of problems. <Yes... and the trouble, enigma of having too little, pulsing in too much, then having too little...> You made an excellent point in that I have shelled out a HUGE amount of money for my tank and equipment, and for me, by far the most important thing is giving the livestock a healthy environment. (I was diving in Fiji last week), and it doesn't take long to become guilty that my fish are in my tank and not in those reefs anymore!!!. <I really enjoy the discussion of these "other considerations"... it surprises me all too frequently that folks don't consider "business opportunity costs" (what otherwise they might do with the same resources), the "null hypothesis" (the "costs" of doing nothing)... in addn. to what they might do/next... Sorry for going on and on re this subjectivity... am avoiding more drudge-ridden, less-fun activity...> I don't mind spending money to utilize technology to help stabilize things. Keeping a strict regular maintenance schedule is tough as I have to be away from home frequently. I just know that over the past 8 years of keeping fish, many fads have come and gone. <Wish I could take you on a trip with me through time... I tried to "sell" folks on protein skimmers through the sixties, seventies, eighties... Calcium reactors are THE route to go for folks who want to optimize their experiences> Just wanted to know from you that Calcium reactors are the real deal. <Mmm, some definitely more "real" than others... do check around on the BB's, and don't sniff at the opportunity to make your own... a lot of clubs have get-togethers for just this purpose...> One final question, if I do get one, it should take care of Strontium and Calcium, correct? <Yes... and magnesium, and carbonate/bicarbonate...> In your opinion, which other supplements should I keep adding? <Mmm, not to be/appear too "slippery" here, if you have an "intensive" situation (like aquaculture), Kalk and Calcium Chloride might be worthwhile additions... if not, skip the last, both... Depending on your other life, feeding schemes, you might want to add iodide, vitamins, HUFA's to the water, foods...> Thanks again for all your help. Jason <Bob Fenner, back to the grindstone>

- Calcium Reactor and/or Chiller - Do I need to have a calcium reactor for my 55 gallon tank and yes I will have a maxima clam? <I would - you will find that otherwise, you will spend a calcium reactor's worth of money on additives - the calcium reactor will make maintenance of calcium easier and more stable.> Also will I need to have a chiller? <That depends on where you live and how warm your house gets. Cheers, J -- >

Calcium reactor FOWLR Is running a calcium reactor for a fish only tank (with liverock) a bad idea ? What are the drawbacks ?  <No. The benefits, high, stable pH, calcium and alkalinity are tangible for all living marine systems> I know it is almost a pre-req for reef tanks with the calcium that they draw, but is there any downside if you don't have a large user of calcium ? I'm mainly interested in using it to control ph/alk, rather than dosing/buffering. Thanks <Not really downsides other than upfront costs of acquiring the gear. If your situation (checked by water testing) doesn't call for much adjustment other than regular maintenance (as in gravel vacuuming, water changes... you might get by w/o... Stocking rates, feeding, use/non-use of live rock... many other factors might contribute to yes/no question of reasonableness of calcium reactor use/augmentation. Bob Fenner> Jim

Calc reactor I was told that a calc reactor is a waste of money and that Kalkwasser was cheaper and a safer way to go, safer because with calcium reactors you always have the problem with hair algae. Is this true? and what is it with a reactor that would cause the hair algae? >> I'd be willing to bet most anything that in a few years your PC will be faster, your car will get better gas mileage, and most all serious reef aquarists will have calcium reactors... they are the easiest, simplest, safest, and LEAST EXPENSIVE means of adding biomineral AND necessary alkalinity... The folks who state otherwise are likely ignorant or trying to keep you on your "supplement" and "livestock replacement" habit...  Don't know what someone is angling at with the "hair algae" reference...  Bob Fenner, who says, take a look at the articles and more about these tools, supplements, calcium.... stored at www.wetwebmedia.com

Calcium Reactors Bob, do you know of any articles and/or literature about calcium reactors. I really want to get one but before I spend $500 I'd like to do as much research on its advantages/disadvantages. are these things really that good? i heard they maintain your reef water perfectly, aside from water changes, of course. any websites that you know of that has literature on these things? oh, and could you recommend any particular calcium reactor or are they all they same? >> There are numerous (hundreds in my files) of articles, promotional materials pieces on Calcium Reactors... I would take a look at the last year's worth of hobby magazines in all the languages you understand... And use the Internet to look at the manufacturer's input... and hobbyist opinions on their respective features, utility. Bob Fenner, who has seen the near future of easy reef keeping... and it is in large part these devices.
Re: Calcium Reactors
Hello again bob...i talked to the sales rep at the Knop calcium reactor place. he told me that i would need a sump to drip the calc reactor into, <Hmm? Nah... can be dripped into main systems...> or, which i suggested, to put the system on a shelf higher than the tank and drip it into the tank, which he said would work as well...my question is what's the difference in dripping in a Kalkwasser solution compared to the reactor solution... <the Kalk's relatively toxic and insoluble... the calcium reactor material not only has biomineral (calcium, magnesium, barium, strontium...) but alkaline reserve (carbonates) as well... compared with Calcium hydroxide (aka Kalk, more akin to oven cleaner...) which only has calcium and hydroxyl ions...> I'm sure with some experimentation and practice, i could get the art of adding Kalkwasser to my tank down to a science to keep my calcium level at a constant. why then would i spend all of that money on a calcium reactor?... <Pls see our site re this issue: Home Page > s the only difference between the two, besides a huge price difference, is the convenience of not having to mix the Kalk solution and measuring it all the time??.. <Far from it... the reactor adds most everything biomineral AND alkalinity wise a captive system needs/uses... the Kalkwasser habit see-saws a system back and forth, rendering depletion of alkalinity, other biominerals... poisoning, to a degree selectively biomineralizing life... w/o live/dead rock and other calcareous substrate, Kalkwasser would kill off everything in such systems...> i apologize for asking you all the time but i sincerely trust your opinion and value it before i would spend all that money on a reactor, i just want to be sure my investment is a worthy one...thanks again >> <And I appreciate your interest and trust... Read, study, converse with others till you've made up your own mind on which way(s) to go. Bob Fenner>

Search for Calcium... Reactor Okay Dr. Bob (is that greeting okay with you?) <What comes is acceptable> In the spirit of a picture is worth a long list of animals, I have include a jpg of my 75. My parameters are: <Hmmm> Ammonia, Nitrite, Nitrate all zero. Phosphate is a 2 <Yikes> , but will come down with water changes. I use only RO, and have just thrown my bottle of Kent Micro Vert in the trash after I read that it is a pollutant (source of PO4?). <Yes...> I add Kent Part A&B 30 ml per week. Kent Iodine 15 ml/week Kent Strontium/Molybdenum 15ml/week, Kent Tech M 7ml w/water change (Instant Ocean). I am running a Top Fathom 110 in my otherwise empty sump. <Wish my name was Kent> I know that you are a big advocate of calcium reactors, and I'm almost convinced. This leads to my questions. <Aahhhhh> 1) I'm a faithful reader of your Q&A where you mentioned that Knop & K2R would be supplanted. Can you tell me by what, the time frame, and what price range? Should I wait for these new units? <Ahhhh, my young friend... do I see? No, no waiting.> 2) I understand that a Calcium Reactor will eliminate my need for Part A&B, but what about the rest of my additives? <Almost all... would be adding iodide every week depending on the types of livestock kept... but yes... this is... about....... it> Any other general suggestions would certainly be welcomed. <Keep your bowels empty and your mind full.... this is borrowed> As always thanks for your time, consideration, and your helpful website, Marty <Be mindful of our limitations my friend. Humans only live about 22,000 days. Bob Fenner>
Re: Search for Calcium... Reactor
Thanks Bob, Do you have an opinion on: http://www.canreef.com/careactors.htm <Hmm, have never seen one... but nice website, clean/clear graphics of what they have... and many aspects of their units are admirable... The size of the chamber, use of Eheim pumps, organization/layout of the plumbing... do know for sure that they will be changing the "closure mechanism" in short order... and if you get/use one of these units, do remember my caution to "GO SLOW" in re-assembling the unit... as the top screws/o-ring format is a pain to "get right... and way too easy to break... you/they will see. Have them contact me if they'd like my two cents (free of charge!) on what other folks have done... they might do to change this one feature> I apologize for the relentless questions; I just want to make a good decision. <No worries> I understand you wishing your name was Kent, but isn't it better to use one brand? <Absolutely... especially one that is made by real scientists, engineers and all round good people (who even have a sterling sense of humor)> And is it true that the average life expectancy is only 60 in the U.S.? :) <Yikes, better up my ante... (For Americans... other rich nations) thx for this. More like seventy something with a couple more for the tender gender methinks... uh, times 365.25... Bob Fenner>

Calcium reactors, supplements Bob am i reading this right, calcium reactors are much better than dosing Kalk?  <Yes, absolutely. Much more safe, dependable, constant... does more... in supplying all biominerals in correct proportions, alkalinity...> will they provide all the necessary supplementation, like strontium, magnesium, iodine etc <Not the iodine...> i have an awful time trying to get/keep calcium levels at or above 350ppm, look forward always to hearing from you, and can u plug any best model reactors from your experience and materials to fill the reactors,  <Best to experiment here, use the new Chatforum on WWM... I am "not happy" with what the trade offers currently... a lot of it ridiculously expensive... Do look into melting down "just" a simple beach-collected material... a bit more maintenance to stir up, replace more frequently, but a better deal by far> i have heard some one say that reactors will not promote good coralline growth is that possible  <Absolutely> thanks in advance rob Huss <Be chatting my friend. Bob Fenner>

Ca reactor Hi again, Bob! I have a question regarding calcium reactors. I noticed that there is no information on the reactor page at WWM. <Yes... much needs to be written, placed... and much of this is at/with magazine and book editors and can't/won't be released till those works are in pulp print.> I read through the FAQs and couldn't answer my question. What is the purpose of the CO2 in using ca reactors?  <The carbon dioxide in solution (carbonic acid) is a weak and dilute source of acid (proton donor, electron acceptor) to "melt" down the alkaline feeder material (generally some sort of calcium carbonate et al.) to provide the effluent water with alkaline reserve and biomineral materials> I assume that you can't work one without the proper CO2 setup.?  <Hmm, well, there are several designs... and many systems that aren't overcrowded, overfed, overlit have sufficient quantity and quality of soluble substrates (rock, gravel)... have sufficient water movement, reductive events to supply these necessary materials otherwise> I noticed people referring to effluent pH in the FAQs. What is that a measure of?  <relative concentration of hydrogen/hydroxyl ions... Please read through the "pH, alkalinity" section on the WWM site here> And what if the CO2 regulator breaks (can it?) and releases too much CO2 into the reactor? How will this affect the system? <Not likely, but if so, would drive down pH too much, too soon, could be deadly> Sorry so many questions, but all I can ever find is "You need this, and this..." without explaining what all these parts are for. Any information you can provide would help. Thanks. Jason <Get your hands on the books listed on the "bibliography/further reading" and subscribe to the hobby magazines for a while here... Let your curiosity drive you to understand the underlying principles in what you're interested in. You will find this very satisfying. Bob Fenner>

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