- 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 -- >

- Adjusting a Knop Type-C Calcium Reactor -
<Greetings, JasonC here...>
Good afternoon crew, here is a really difficult question for you, i am running my model c off a t-piece on a circulation powerhead in my tank, i have been playing around with the gas count and i have found that if i go to about 20 bubbles per minute i get gas block (not me personally but my reactor). <Perhaps not enough water pressure.>
I was thinking about changing the feed to a dedicated powerhead (any suggestions) maxi jet, mini jet etc., what litre rate per hour would be suitable for the task, in your opinion do you think that this would give me greater feed capability and help to alleviate my gas problem (again not me, but my reactor). <Considering that you're trying to maximize the output of this reactor, I'm not sure a dedicated powerhead will provide sufficient pressure for this mode of operation. How about a T-fitting off your return pump, which will provide sufficient pressure to get by the gas build-up at the top of the reactor.>
Any thoughts, ideas, help? Always greatly appreciated.
Paul M, Manchester
P.S. I have spoken to some guys over here and they claim to be putting about 60 bubbles per minute through theirs, is this possible? <It is possible.> and secondly wise? <No, not really - there seems to be a trend towards trying to get incredibly high alkaline effluent out of a reactor these days, but Daniel Knop points out in his instructions that effluent shouldn't be above 17 dKH [15 is ideal] because the additional calcium in the effluent will not go into solution as well, and will more often than not precipitate out - often right on the tip of the output valve. Cheers, J -- >

And now....plumbing, Calcium reactor
<Sorry Kent, I saved your post as a draft until I could answer your calcium reactor question and it got posted before I could finish! I'll continue..>
Looking for plumbing recommendations. (Clarity 135 with sump and calcium reactor). So far I only intended to use 1 Dolphin 2100 pump at about 4" head.  The skimmers are in sump with their own pumps.  The Dolphin get it's direct input from the sump.  Am I supposed to drill another hole in the sump and add a bulkhead to supply another pump for the Knop S-IV and put the drip back
into the sump? If so, the input vs. output of the reactor won't be equal will they?  If they are then question answered.
<Feed the reactor with a tee off the pump or use the drip line it comes with. The output is very low, so the input will be low as well. For maintenance, set it up in a convenient spot and plumb with tubing.>
Also, I am thinking I have to T the output of the 2100 to go to each return, and likewise T the drains into the sump.
<Yes, use valves to adjust flow to each. I don't know if you have to T the drain/overflows, they could have individual lines to sump if it's designed for them.>
This seems like an equal in equal out deal with the exception of the bulkhead out of the sump the calc reactor.
<Yep, the tank will only drain what is pumped up into it, with overflows properly set-up. The calc reactor will hold the majority of it's volume, so that water is not going to drain into sump and is not a factor in water level. There is no need for a bulkhead, this is a simple tubing set-up.>
Can water height in the tank be used to adjust for drain rate versus return rate to compensate for any inequalities in sump levels due to skimmers and or the reactor?
<How this works is, main tank water level is constant. Sump level varies a bit normally. The way you set this level is to fill the tank with everything off until it overflows into sump and fills to highest desired level. Now turn it on and it will be operating at the highest water level it should.  When and if power goes out, it will drain down to the fill level, provided you have siphon breaks in your returns. The tank drains from the surface, so it can only drain what you pump into it.
Thanks loads, I wanna do this right from the start and have the least amount of probs.
<No problemo!  I hope this answers your questions...if not, let us know!  Craig>

Last Reactor Question
Hi again,
<Hello, JasonC here...>
Well I just got the Knop S-IV reactor from Marine Depot and it's broken.... the clips that hold the second chamber are broken. <Wow... that's hard to believe, they are packed so well - was the box damaged in shipping?> SO, after calling them up to report this they advised me they don't have any more S-IV's in stock, but that they would be happy to replace it when they get another shipment or if I want they will immediately ship me out a Korallin 1502.  I'm asking for a straight opinion as to which one I should now go with, wait for another Knop S-IV to come in or get the Korallin 1502 instead. <Well first I'll answer the question - I would stick with the S-IV because I really like it, but you have another option that I'll cover in a sec...> The 1502 is much cheaper than the Knop. <Yeah, and not as well made IMO.> I also have no immediate need for the reactor at this point so there's no urgent need.  
Also, the salesman is telling me that the 1502 is too small for a 135 gallon tank.....it's supposed to be rated for 400 gallons though? <Doesn't make any sense to me.>  Is the 1502 large enough for a fully stocked stony tank?
<Probably.>
My thinking is they would rather keep more of my cash than refund the hundred or so bucks. <It is looking that way... here's what you can do. I just spoke with Diana Fenner of Knop Products - you can return that reactor directly, and she'll gladly replace it. She has plenty in stock - please send it to Knop Products, 8586 Menkar Rd., San Diego, CA 92126 and you'll get another one sent right out. Sorry about that.>
Thanks much again
<And thank you for sharing... Cheers, J -- ><<In 2006 the distribution of the Knop line went to Marine Depot. RMF>>

- Measuring the pH of Reactor Effluent -
How are all these folks measuring the pH from their reactors? Hold the probe under the drip? We just move the probe back and forth from under the drip then back to the sump input? <I can't speak for everyone, but I'll tell you how I do it... collect a small amount of the effluent in a cup, enough to get the probe on my digital meter working correctly, and then put the pH meter in there... you could also use that collected effluent in a test kit I suppose. Cheers, J -- >

- Calcium Reactor Selection -
Korallin 1502  vs. Knop S-IV......   
Is it worth the expense of going with the 10 Gal C02? <It's your money...> How long does the 5 gal last on a 135 tank chock full o coral & clams??? <Hard to say exactly - I would guess a 5lb tank would last at least six months. I use a 10lb tank and wasn't able to empty it in a year.>
The Knop advertises it's for 150 +....that's cool for a 135 tank? <Yes, that's fine.>
Also, on the subject of Controllers, to save time searching, if I'm not gonna use OZONE, do I need an ORP probe? <Not unless you just want to know the number...> Can the Aquatroller II measure KH or some factor of it using the pH probe? <Not that I am aware of.> What do you use a conductivity probe for?  Salinity? <That is correct.>
Thanks again
<Cheers, J -- >

- Calcium Reactor Selection -
Good people of the Wet Web,
<Good morning, JasonC here...>
After reading for endless days, and reading contrary information, I am just gonna get all the equipment now and be DONE with it.  After digging around for days and only now finding that I shouldn't be using a wet/dry on a reef system (after I already ordered 1) I will just remove the media from it and use it as a sump, skimmer and a place to put a calcium reactor.  After already bugging everyone about everything else, I now bug you about your opinions as to worthiness and ability or the two following pieces:
- Korallin C-1502 <Is a worthy piece of gear.>
- KNOP S-IV <Is my favorite of the two - I own this model, and is my favorite Knop reactor, much more simple than the others.>
The Knop is more expensive by about 70-80. <In my opinion worth the money.> Does one have some feature the other doesn't? <Not really, just a good design.> Is one more efficient than the other? <No.> And finally, can they both be used in the sump rather than divert pressure from the return line? <I'm not sure I follow - water has to be forced into the reactor somehow... just placing the reactor in the sump will not be sufficient. You have three choices, a small dedicated pump, a t-fitting off the main return pump, or a siphon from the tank. Where you actually place the reactor will make little difference.>
Thanks amighty!
p.s.  I'm an empirical kinda guy, wouldn't it be easier for those setting up an aquarium to have access to the most accurate data available, that is to say that after the tests are run on equipment and resulting conditions are known, can't we just publish the data and go "HERE, I TOLD YOU SO!  THIS METHOD (OR EQUIPMENT) HAS PROVEN TO BE THE BEST FOR GETTING THE DESIRED RESULTS, PUBLISH IT AND SPREAD THE WORD AS GOSPEL!!"   end of discussion. <Every situation is different - it's best to tackle them individually - what works for one will not necessarily work for all.>
Live from dream world,
Toilet Tank
<Cheers, J -- >

- Calcium Reactor Questions -
<Greetings, JasonC here...>
I hooked up Korallith calcium reactor. I have never had problem with algae. I have been into marine aquaria for about 6 years. Could the reactor be leaching to much co2 into the water. <It's possible, but typically modern tanks - with protein skimmers and overflow devices tend to blow most of it out. Instead, I would suspect the media that you are using in the reactor - there are some of dubious quality which leach phosphates in addition to calcium carbonate.> I use Ecosystem aquariums miracle mud for filtration.
I disconnected the reactor, it does not seem to be getting worse but i have to pick it out. How can I accurately hook up the reactor so I don't have problems, and get good results from it. <Please read this article:
http://www.wetwebmedia.com/calcreactors.htm
Cheers, J -- >

Reactor Media - 2/13/03
Dear Anthony, thanks for that link, I've had a look and they look like they could really do the job, and they're reasonably priced,
<excellent!>
I was wondering if you might be able to shed some light on my small dilemma with my reactor, I have a Knop model c (good piece of reasonably priced kit, we can pick them up over here for £100.00 without gas and gauge), <agreed... I like them very much> anyway the thing is i have always used the CaribSea arm media in the past but my L.F.S have run out and i have changed to the Korallith, <a much better move in my opinion. I'm not a big fan at all of CaribSea media> the only problem is trying to get the reactor ph to 6.5.
At the moment its running at about 6.15 I've just bought myself a hand held ph meter to try and test accurately, my co2 bubble count is 14 and i have been dosing on 60 drops per minute, but at this setting my dKH is coming out at 27 degrees (German) and i know it should be around 35 degrees, i have been playing around with it (i.e. decreasing the number of drips down to 50 to see if this would raise ph, but it wont budge above 6.20), when i was using CaribSea i just used to set the reactor to dKH 35 and leave it, any ideas?
<absolutely... my first (and confident) guess is that the media is too large. Knop has more than a few grain sizes. I'm guessing you need a smaller grain for your sized reactor. By chance does this seem possible? Is the Korallith coarser than the ARM you were using? Should i try and set the ph at 6.5 or go for the dKH at 35.
<if the previous settings ran well, I'd like to see you continue with it>
I must admit this is driving me nuts at the moment, everything in the tank is great but you know how it is we reefers are perfectionists (ha! ha!).
<no worries... I suspect this will be easy to tweak>
All the best Paul
(P.S. went for a great Indian meal last night, chili chicken and pilaf rice, absolutely superb but my god, i had a very bad case of Gandhi's revenge this morning)
<Ha! What's especially funny is that here in America we call it Montezuma's revenge. Yours is funnier for the British-Indian history, though <G>. I do hope that you had a seat belt in the lav to keep you secure during the endeavor!>

- Alternatives to CO2 bottles -
Hello there, <Hi, JasonC here...>
I was reading several sites that describe a DIY CO2 injector (basically for freshwater plants). I was wondering if it is possible to use this method in conjunction with a DIY Ca Reactor. I know that a downside would be weekly addition of yeast in the CO2 reactor to create CO2. But is this a possible alternative to using an expensive CO2 tank??? <Not typically. The amount of CO2 needed for a freshwater, planted tank is not as high as required for a CO2 reactor. Practically speaking, you can pick up a 10lb bottle of CO2 from a local tank supply - when I lived in Western Massachusetts, it was Miriam-Graves - for roughly $100, filled. You end up owning the tank and refills are less than $10. I ran my reactors for almost a year and never emptied the bottle. So really... over the long haul, they aren't that expensive. I really wouldn't recommend a DIY project to supplant a CO2 bottle for a calcium reactor.>
-Randy M. Yniguez, MA
<Cheers, J -- >

- Calcium Reactor Question -
And hello to all those in the know! <Greetings, JasonC here...> I haven't even set up the tank yet...135 gal. Obviously this will be a reef tank and to start it off I will have 135lbs of rock in it to cycle.  From there I assume it will just be a mix of fish, and many different corals. <Uhh... don't assume - plan.> Since I will be cycling the tank with the rock, when should I be setting up the reactor? <Depends... I wouldn't bother until you have stony corals or clams to worry about - the fish don't really need calcium. I will reiterate, because I think it's important - do formulate a plan for all this, don't make assumptions unless you have money to throw away.> Do I set the thing up when I set up the tank and run it while cycling the tank, wait to cycle then hook it up? <Don't bother with it during the cycle - if this is your first marine tank ever, then your hands will be full getting the tank through the cycle.> And how do I go about setting the rate? <Start by reading the directions that come with the reactor - they are all different, but if that fails, read this article and use it as a guide:
http://www.wetwebmedia.com/calcreactors.htm >
Do I just monitor and let that be a guide assuming that I will only be using a small amount since I will only have rock to start? After getting redeye from surfing for info, I guess the consensus is to set up the reactor when everything is in balance. <That is correct.> So, would it be fair to say that soon after cycling I should fire up the reactor and continue on from there? <I wouldn't bother until you've got something in the tank that has high demands for calcium, and I would predict that is several months away if you do it right.> Eventually I feel the tank will be loaded with coral and will need the reactor. <Eventually, sure.> OR should I just go with dosing from a jug o' calcium until I get more corals in the tank? <Now you're thinking...>
Man, that was a lot of text for the simple answer I know is forthcoming!   
Thanks again buds!
<Cheers, J -- >

- Is that where Calcium comes from? -
In reference to the last reactor question from me, I was curious as to whether the Aragamax bedding I will be putting in slowly dissolves to supply calcium to the tank if I don't dose or use the reactor? <You are correct about calcium being freed from the sand bed, and from the live rock for that matter - this is how it happens in the wild. But to reiterate from the last email - don't worry about bulk calcium until you have something in the tank that needs it. Otherwise, natural processes will be best.>
tanks again
<Cheers, J -- >

- Calcium Reactor Questions -
<Greetings, JasonC here...>
Good evening crew, i have been looking through the site with regard to Knop reactors, i have a model c and i think it is a very good piece of kit and reasonably priced, my only minor problem is that i have been using the CaribSea arm media for the past 12 months or so, and i have not been very impressed at all with the performance, so i have just changed to the Korallith, the only bugbear is that i am trying like mad to get the reactor effluent down to ph6.5 as instructed and I'm having no joy at all, i am putting 18 bubbles per minute through with co2 and my effluent rate is 35 drops per minute, the best i can get down to is about 6.85-6.95 and i test with a hand held Hanna ph meter, can i put more co2 through or will this give me a co2 lock in the chamber, also do you guys think that its best to get the ph down or just align the dKH on the effluent side and let the ph fall wherever (i.e 3-4 times tank dKH). <Actually, a pH of 6.8 on the effluent side is sufficient. If you want to lower that a little more, you could just slow down the effluent drip rate... cause the water in the reactor to stay in there a little longer.>
Many thanks your comments greatly appreciated as always.
Paul, Manchester
<Cheers, J -- >

- Calcium Reactor Questions -
<Greetings, JasonC here...>
Hello again oh wise ones. <Oh stop it, I'm a long way from wise ;-) > I have the 180 gallon acrylic with a 60 gallon acrylic tank that I have running under the tank with frags and a few fish.  I have had a Knop C calcium reactor running down next to the 60 gallon for the last year but lately the effluent alk is down to 19 which isn't keeping my tank effluent up above 4.  When I started using the reactor the effluent was up around 35-40 which was keeping the tank alk around 10-11. My calcium is between 345-390 with the addition of the Kalkwasser slurry on a nightly basis to keep the pH up between 8.1 and 8.35.  I use the test kit that turns from blue to green to yellow.  I'm not sure which test kit it is.  My CO2 bubble counter is set at 4-5 bubbles per 15 seconds.  The effluent drip is running at about 1-2 drops per second.  I am using Carib sea media in the reactor.  What would you recommend that I do to get the effluent up to par so as to keep my main tank alk up above the 6-7 that would be the low end that it should be? <Two things, I would can the Carib Sea reactor media - the quality is too inconsistent - and switch to the Knop Korallith which is the only media that Knop guarantees will work with their reactors. Likewise, it sounds like you are expending your media rather quickly - it's probably time to swap it out.> I have had to add Seachem Reef Builder lately to get the alk up a bit to 6-7.  Any help would be greatly appreciated.  Thanks again, Jeff
<Cheers, J -- >

- Kalkwasser and Calcium Reactors -
Good morning crew. <Good morning, JasonC here.> I was reading some of the archive files and read the mention of possible problems combining a calcium reactor with dripping of Kalk. This was in regards to such thing as higher ph and loss of magnesium. What are the problems associated with a ph of 8.6 or higher should that occur? <There are a number of problems... the whole system is really that, a system of chemical balance - calcification, denitrification, etc... when any one parameter is either too high or too low, one or more of these processes will either slow down, or speed up. In the case of calcium additions, the danger is that alkalinity and calcium levels will become too high, saturating the tank at which point the calcium will precipitate out of solution until the calcium is consumed. This is often referred to as a 'snow storm'. If you are dosing both, you need to keep a very close watch on your calcium, alkalinity, and pH levels. One can does both - a constant from the reactor and perhaps small weekly doses of Kalkwasser, but to allow the Kalkwasser to drip in at a constant rate like the calcium reactor is an invitation to problems. Just like most things in life - moderation is the key.> As always, I appreciate your help and thanks in advance.
<Cheers, J -- >

- Calcium Reactor Selection -
Hi Bob, <Actually, JasonC today...>
I just built a 180g SPS reef tank with 100g sum, and I'm looking for a Calcium Reactor.  Could you tell me which one is the best for me? The Knop model, the Aqua Medic model, the Advanced Reef model, or the Marine Life model.
<Personally, I don't have much experience with any of those except the Knop reactors, which are excellent.>
Thank you.
Khanh Do.
<Cheers, J -- >

Re: Calcium Reactor
Hi Bob and JasonC, <Hello...>
Thanks again for replying to me so quickly. <No problem.> About the Knop Calcium Reactor, as I know it has two models, Knop-C and Knop-HD, which model should I choose for my 180g reef tank? <Actually they have more than that... four or five I think.> I think about Knop-C, but I don't know exactly how big of a tank it can handle. <The type C is rated for 180g... but you previously mentioned a 100g sump - your system is 280g, must fit the reactor to that.> I did some researches but each company said a different thing??? <Some are more conservative than others.>
So could you tell me about the Knop-C please? <I would go for their new reactor, the S-IV [that's the Roman numeral four] which has an integrated bubble counter and pump inside the reactor. A very nice package with a small foot print. Would certainly be more than adequate for your system.>
Thank you, Khanh Do.
<Cheers, J -- >

- Retrofit Calcium Reactor -
Dear Crew
<Greetings Jim, Jason here...>
I have a 130 Gallon reef tank with various species of Stony Corals in it.
These include :-
2 colonies of trumpet coral
1 Faviid
1 Euphyllia
Halimeda calcareous Caulerpa
various leathers
I will possibly be adding a Trachyphylliid brain in the new year. I have managed the stock I have in currently with calcium, and alkalinity supplements; but i am thinking of adding a calcium reactor to remove the need to keep throwing in these buffers as they are quite costly. <I'm sure if you added it up, you could have purchased the reactor already.>
I will be using an old aqua-medic De-nitrifying unit as the main unit (a device in my opinion that no-one should ever need, it leeched hydrogen sulphide into my tank originally; no offence to aqua-medic or their products). First of all is this retro fit ok? <I'm not familiar with this exact unit, but unless it seals air-tight, I wouldn't do it.> My LFS says all that is required is to buy a C02 dosing kit with a solenoid and bubble counter and fill it with the required media. <A CO2 dosing kit? That's not going to provide sufficient CO2 for a reactor - I think you would find yourself spending as much on dosing kits as you were on two-part additives. Best to purchase a CO2 tank and regulator to go along with that bubble counter.> Second of all will it leech Hydrogen sulphide into the tank as it did when it was a De-nitrifier? <It shouldn't unless you are using something other than a calcium-based media in the reactor.>
My water parameters are
calcium 380
alkalinity 8.2
PH 8.4
Lastly, do these units require lots of maintenance? <Not really.> I know you have to shake the media etc, and change it every 6 months. Is that about it? <For the most part, yes... perhaps check the effluent valve/fitting to make sure your drip rates stay constant - sometimes they slow down, which would affect the dKH and pH of the effluent.> I've also read that to stop C02 leakage into the tank you can get the effluent to drip into the outflow of the skimmer is this correct? <That is correct, but it's better to determine that you are even having the problem first. Most modern reactors, adjusted correctly, consume most of the CO2 in the reaction process. Any additional CO2 will most likely be blown out by skimmers and overflows. It is typically not a concern, but if you are worried, just test first.>
cheers
Jim Griffin
<Cheers, J -- >

Re calcium reactor
Dear all
<Greetings, Jim, JasonC again.>
Just as a reply to my e-mail sent yesterday. The De-nitrifying unit by aqua-medic is totally air tight and has a slow pump within it to circulate the media. The C02 doser I was on about is in-fact as you correctly state a gas bottle with a solenoid and bubble counter. <Ah, good one on the CO2 bottle, although I would just quickly point out that a penny saved is sometimes two pennies spent later on. I'm still not completely sold on the idea of using this unit as a calcium reactor - but still... good luck.>
I will proceed ahead with the conversion of the unit to a calcium reactor. I currently have a very large profusion of purple calcareous algae (its even plating in some places). Will the calcium reactor make this algae growth go out of control? <Properly adjusted, it will certainly boost their production.> Should i scrape it all off my tank back and sides? <Only if it annoys you.>
My dKH is currently 8.4, and I'm worried if the reactor pushes this to 12 or 13 that the calcareous algae population will explode.
<Nothing to be afraid of, just may need to step up the glass cleaning. No harm is done by coralline growth.> Also as an aside, I was wondering if you could tell me whether my tank is over stocked, the tank is 110 gallons (including displacement for live rock). The tank has become more 'reef' in the last six months or so, with the addition of corals (leathers and stonies). I have :
1 Hippo tang
1 Flame angel
1 Midas blenny
1 Banggai cardinal
1 pyjama wrasse
1 sand sifter goby
1 maroon clown
1 tiny red eye goby (1 inch long)
I am thinking of removing the hippo tang (as he is large) and maybe the wrasse. <Doesn't seem crowded to me...>
cheers, Jim Griffin
<Cheers, J -- >

Calc Reactor Q's
Hello Jason,
<And hello to you.>
I've read part of your FAQ about CalcReactor and it was very helpful. <Ah good, glad it was useful for you.> Maybe I can ask you some other question... When I want to buy e.g.. AquaMedic
CalcReactor should I buy any other equipment (ph Computer or Sth)? <And perhaps a CO2 bottle and regulator. I don't think the pH "computer" or controller is necessary but because you will need to measure pH quite a bit at the onset, a digital pH probe will save you a lot of time.>
And the second one: are soft corals need Ca to live? <Not to the extent that stony corals and clams do, but most all soft corals contain sclerites, small slivers of calcium which help them form and maintain their various shapes. Free calcium is needed to form these sclerites, but certainly not in the quantities needed for stony corals.>
Thank for answer <You are welcome.>
P.S. I saw that you have probably Polish surname. I'm living in Poland and if you want you can answer me in Polish. <I'm afraid that my Polish is non-existent, and many generations removed. Sorry.>
Bye, Piotr
<Cheers, J -- >

Calcium Reactor affects on tank alk/Ca level
Dear WetWeb Crew:
<Greetings, Kevin, JasonC here...>>
Once again I need your experience in answering a question I have; your previous responses to my past questions have always resulted in success for me with my 2 yr. old 100 gallon reef tank.
After several months of non-use, I have started to again use my Korallin Kalkreactor with a 75%/25% blend of Korallith and CaribSea reactor media; prior to restarting the reactor, I was using 2 tsp of Kalkwasser/1 gallon distilled water to maintain alkalinity and calcium, but with the reactor running, I have decreased the amount of Kalkwasser I added to the distilled water to 1 tsp.  I also do a 10 gallon water change every week. After 2 weeks of running the reactor I was hoping you can help me with some questions regarding the properties I have measured.
Tank water:
Alkalinity - 4.2 meq or 11.8 dKH
Calcium ­ 320 - 330 ppm
Reactor effluent (drips into sump water over a submerged Aqua C skimmer Rio 2500 pump):
Alkalinity ­ 13.8 meq or 38.7 dKH
Calcium ­ 480 ­ 490 ppm
I mentioned that the reactor effluent drips into the sump into water that is over my skimmers pump; I do this to insure that any excess dissolved carbon dioxide is pulled into the skimmer and vented off by the agitation. Tank pH is 8.3.
After always reading that tank level calcium needs to be maintained 400 ppm or higher, I was concerned that my calcium level in my tank was to low, but since using the reactor my Tridacna derasa and squamosa are showing increased shell growth, my just added Caulastrea coral is plump and extends feeding tentacles at night, coralline algae is covering all the rocks and has to removed from the sides and front tank glass regularly, small polyp corals that had disappeared prior to the use of the reactor have started to show themselves again and the fish continue to be active and feeding aggressively (even my powder blue tang). The only possibly negative change is my two Sarcophytons do not extend their polyps as fully as they did prior
to the reactor, but the main body of each becomes fully erect once the lights come on in the morning and both Sarcophytons are getting larger, taller, and plump.
My question (sorry for the long introduction!) is am I worrying to much about my tanks calcium level vs. what is said in popular literature and in reality, based on the reaction of the tank inhabitants, is everything in good stasis. <I would say yes. If you had the opportunity to go and measure dKH and calcium levels around the world, you would be hard pressed to find the high numbers which people tell us we need. There is balance somewhere in the middle as evidenced by the growth of your clams and coralline algae. I know that high alkalinity: I calcium are mutually exclusive, but why is the reactor effluent calcium level not affecting the tank calcium level as much as the reactor effluent alkalinity level is affecting the tank alkalinity level? <My thinking here is that the effluent dKH is too high. You need this to be in the range of 15-ish. Anything higher will make it difficult for the calcium to go into solution, and more likely will precipitate out, forming deposits on the effluent valve and elsewhere. Do recall that the enhanced alkalinity brought about by the reactor will cause the calcium in your sandbed and live rock to add to available calcium. I would try just a little less CO2, and continue with the same drip rate. Ideally, you want the effluent to be at about 15 dKH and the pH to be about 7.6> Is it that the calcium level in the tank is being used up at a greater rate then the alkalinity? <That is a factor, but I'd try lowering the dKH of the effluent first - much easier to affect changes here.>
Any input you can supply on this would be much appreciated. Thank you in advance. Kevin
<Cheers, J -- >

Knop C Reactor 
I am interested in getting one of your Knop C calcium reactors.  I have heard though that an additional pump (in addition to the pump that comes with the reactor) is needed for it and needs to be placed inside the sump to feed the reactor. I read this in a review but when looking at these reactors have seen nothing about this so first, is it true this 2nd pump is needed?  Also, if it is necessary what pump is suggested?  Thank you for any help. Mark Weigl
Hi Mark, Jason C here... It is not required to have the additional pump. I'm assuming here that you are thinking it would be used to feed the reactor with water. You have other options here. You can also use a siphon or T-fitting from your existing return pump to feed water into the reactor. You might want to read this article, it should answer your questions: http://www.wetwebmedia.com/calcreactors.htm Good luck. J -- >

Knop C Reactor
Hi Mark, Jason C here...
It is not required to have the additional pump. I'm assuming here that you are thinking it would be used to feed the reactor with water. You have other options here. You can also use a siphon or T-fitting from your existing return pump to feed water into the reactor. You might want to read this article, it should answer your questions:
http://www.wetwebmedia.com/calcreactors.htm
Good luck.
J --

Re: Anemones, Calcium Reactors, etc.
Thanks for the quick reply Anthony!  I have 1 Hammer coral, 2 bulb tip anemones, and one large carpet that is quite happy.  
<ahhh... yes, my friend. The two anemone species are especially problematic. We get buried in e-mail on issues around this. All seem to look good for as much as a year. In some cases towards two years. Almost none will make it beyond 2 years (allelopathy). The carpet will overwhelm the other anemones and many of the coral by then. Extremely noxious>
It is attached to a rock and the bottom of the tank.  Any ideas to remove it without ripping it's foot?  
<yes... many ways. But have some rubble (small and loose) piled near to its foot/base. Then shade the light directly above the anemone with a small ceramic plate/dish or like safe obstruction between the light and the water surface. This is an easy an gentle way to move most anemones (they will crawl onto the rubble  and into brighter light).>
Also are the Fiji plate corals in the tank, are they considered LPS?  
<yep... very hardy and easy to propagate keep... but extremely "hungry". They are less than 80% satisfied by the products of photosynthesis under the best lights. More than 20% of daily carbon needs to come from target feeding. This animal needs fed almost daily in aquaria or it starves in less than 2 years (most in less than 1). If fed... they are incredible! Hardy and fun>
Should those be removed also?
<Hmm... its not a pure science. All corals produce some amount of chemical defense. We are best to simply minimize unnatural aggression. 2 LPS in a tank of SPS is no big deal... but 10 is too much. How can we satisfy corals collected in 40-60 foot of water (LPS) with others collected in less than 10 feet? Not in the confines of a 24"tank under standardized lighting. Some fare well while others suffer in time>
Thanks for the "heads up" about chemical war between the animals.  I will remove the anemones and the LPS this weekend.  
<definitely the anemones ASAP. By themselves in a sunlit window would be magnificent! Think of a 60 hex with only that big bad carpet anemone in a southern window and a dozen humbug damsels playing in it!? Wonderful>
About the calcium carbonate, I do add the B-Ionic but have never shaken the container before doing so.  
<Aieeeeee! My ears <G>>
Only at first when I received it. Could be my culprit.  
<OH ya! Its a big problem. The ingredients are all clear but separate in the bottle and get dosed imbalanced (you can actually see the separation if you let the solution set over night in a clear graduated cylinder... looks like a thermocline)>
I like the Knop C reactor also but the Korallin C 1502 might be better when I get a 180 gallon tank in the future.  Any thoughts on the Korallin models?  
<no strong preference for any brand by me. I like Knop for their longevity and reputation. Some aquarists do not favor its smaller size. The new dual chamber Knop reactors are pretty sweet though! Have you priced them at Di's place yet? General Aquatics?>
For such a pricey piece of equipment I don't want to buy a second one, if you know what I mean. Thanks for all the help! Brad Stefanko
<Agreed... best regards, Anthony>

Information on Calcium Reactors in Australia
I would like some up-to-date information about Calcium Reactors and available brands in Australia.
<G'day mate! check the articles and facts at Wetwebmedia.com for general information on calcium reactors. If you are interested in purchasing a reactor check with the etailer links at Wetwebmedia or click on the OzReef link. Oz is located in Australia.>  
Thank You in anticipation
<You're welcome! David Dowless>
George Derrick

Knop Reactor
Greetings, JasonC here...
Dear crew, good evening 20.00 hours Sunday evening over here in good old Blighty, thank you for your very explicit answer to my question last week Mr. Fenner, it was greatly appreciated and very enlightening.
<<Good evening, or good morning is it?>>
My question today is this, at the moment I am using CaribSea arm media in my Knop model c reactor, I do a 5 gallon water change every weekend (using instant ocean), I feed my corals daily with Knop coral vit f and I also dose once a week with Kent strontium/molybdenum and iodine, I also use Knop coral vit Combi which I dose weekly as well I have a good mixture of hard and soft corals my tank volume is 65 gallons.
>I have been hearing a lot of good reports about the SeaChem reef plus in terms of the outstanding coral growths that can be achieved when using it as a supplement, I don't mean to put you on the spot but which one would you buy Knop coral vit Combi or the SeaChem, by the way my calc is 460ppm and my dKH is constant at 9.0, ph is about 8.2. and my phosphate is 0 nitrate 0 I use a canister filter under my tank which powers a 25watt Vecton UV and a Teco chiller, I use ROWAphos to eliminate the phosphate and carbon which I change every 4 weeks, biological filtration is entirely by Fijian live rock.
<<My feeling about these two supplements [the Knop Coral-vit and the SeaChem stuff] is that they are, as they say, "six of one, half-a-dozen of the other." Meaning that you probably will continue to enjoy good results regardless of which on you use. While both are good, neither has a special ingredient that makes it superior to all others. I'd keep on with what ever fits in your budget.>>
Many thanks once again for your reply last week, and keep up the good work your site is invaluable as an unbiased opinion in the ever increasing and cost spiraling world of reefkeeping.
<<Will do!>>
Paul Matthews, Manchester, England.
Cheers, J --

Calcium Reactor
What brand of Calcium Reactor do you recommend for a 215 reef?
<Knop is my favorite but there are many others. Try a word search at Wetwebmedia.com for other suggestions.
Thanks, Steve
<You're welcome! David Dowless>

Calcium Reactors & Supplements
Hi Bob!
<Steven Pro in this afternoon.>
Have you any knowledge of the Intermarin calcium reactor?
<Nope>
And could you please clear something up for me.
<Sure>
In my research before buying my live corals, almost all sites I've looked at say the corals will thrive better with the addition of trace elements and iodine and such.
<It depends on what you mean by trace elements, but I agree. I and recommend others supplement for calcium, alkalinity, and sometimes iodine. In addition, I feed the tank a variety of appropriate foods.>
Now with the introduction of these supplements (or so I am assuming since your site says that's most likely what it is) has come my algae problem.
<There are other possibilities. Please be sure to explore all sources of nutrient imports and inadequate export mechanisms, but I agree, some supplements are nothing more than pollution in a bottle.>
So can I toss out my supplement bottles and figure on my corals getting enough of the trace elements and such from water changes?
<This depends on your tank and its demands. Some systems can be maintained through water changes alone, other require dosing due to stocking levels.>
Except for the algae, my water is fine. pH and all are well within ranges and my skimmer is removing between 2 and 3 cups a week. I am feeding my fish very lightly in a attempt to prevent any more algae growth but I do add the recommended amount of plankton for the corals.
<Please research both your corals needs and the appropriate foods. I am not sure what you are referring to when you say plankton or even if this is right for your corals.>
Do I need to maybe cut back on that as well?
<I cannot be sure. There are other possibilities; source water, salt mix, water changes, etc. Do read through what we have available regarding nuisance algae and its causes, develop a comprehensive plan of attack, and go for it.>
Thanks, Robert
<You are welcome. -Steven Pro>

Calcium Reactor
Gentlemen, I have a calcium reactor and have some basic questions. The two components that you can change are the bubble count and the outflow. What are the ramifications of each? Does a higher bubble count increase alkalinity, a higher outflow or does both?
<Increasing the bubble count adds more CO2 to the reactor, lows the pH, and increases the amount of material dissolved. Slowly the reactor effluent increases the contact time of the water in the media and also increases the amount of material dissolved.>
Likewise reducing the bubble count and outflow would have what effect? Second, if your sand been becomes depleted and/or is lower in some areas, is it better to replace it with additional live sand from a store or just gradually build it up with the Caribbean Beach Play sand out of the bag?
<It is best to do both. You can build up the majority of the depth with dead, dry sand, but it is beneficial to periodically add some more live sand or detritivore/sand bed recharge kits to increase and diversify the population of the critters.>
Does it matter? Thanks in advance.
<You are welcome. -Steven Pro>

DIY Calcium Reactor?
Quick Question, do you think that I can make a calcium reactor out of an old Magnum 350 canister filter by just using the canister for the media for crushed coral.
<The media is unlikely to dissolve at normal aquarium pH's. That is why calcium reactor inject carbon dioxide, CO2, to create carbonic acid, low the pH inside the vessel, and dissolve the media.>
Thank for your time and effort, Tim
<You are welcome. -Steven Pro>

Kalk and  calcium reactor combo? OK!
Bob, I am currently running a 500 gallon reef tank with mostly SPS.  Due to some algae outbreak I have recently added Kalk through a night drip method.
<OK... I agree with the night dosing of Kalk... but wonder why the direct correlation with algae outbreak and lack of it? Ultimately I agree that it may help as high pH and the precip of Calcium phosphate by Kalk is indirectly helpful... but a nuisance algae outbreak requires address of the nutrients causing it (need for better nutrient export: cleaner source water, better skimming/daily, etc)>
It seems as if some of the coralline has recently turned white.
<the coralline bleaching can be caused by many things... change in light from new lamps or a sudden use of carbon, water change, exposure to light in air (water change left algae high and dry under baking lights), skewed Ca/ALK dynamic (one high one low)>
Is this combo a long term problem in the works.
<not at all... Daniel Knop himself has suggested that Kalk can compliment a Knop reactor. I agree... but Bob doesn't think it is necessary. The advantage of using Kalk with the reactor is that Kalk will indirectly support alkalinity while providing calcium. The reactor is mainly boosting ALK and with the redundancy of both the system is likely to be more stable if you test and tweak regularly/as necessary. Again, I see no problem. Kalk has advantages over reactors too... besides saponification (enhancing protein skimming)... Kalkwasser is self-cleansing: almost all impurities in Kalk prec out in the high pH solution (like copper and other metals)... however, the media in a calcium reactor simply dissolves and bleeds those impurities into your system. Hence, a bad media for the reactor can contribute to a nuisance algae bloom.>
Would appreciate any thoughts on the matter.  Thanks  Terry   Using a Knop reactor at all times and night drip of Kalk.
<I use a Knop reactor myself. Love it. Best regards, Anthony Calfo>

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>

Adding calcium reactor to reef tank
Guys, thinking about adding a cal reactor to my 450 gal reef tank. Any suggestions on a brand or model for trouble free operation? Thank you, Paul
<Please read here: http://www.wetwebmedia.com/calcreactors.htm and the linked files, FAQs beyond... Bob Fenner>

Calcium reactors
Gentlemen, how are you?
<Very well, thank you!>
Here is what I've run into. I was just about to purchase a Knop calcium reactor for my 90 gallon and I am told they no longer sell them in the good old USA. Is this true?
<Completely false! Bob's wife, the lovely Diana, is a/the importer of Knop products into America.><<Mmm, no longer. Oh, still the wife, not the distributor for Knop in N. America... RMF>>
And why? I am now looking at different reactors and don't really trust anyone but you guys. Everyone else out there is saying different things about different reactors. I was told the Aquamedic was a good one by one person, and another told me that the Aquamedic was not so hot and he liked the Precision Marine.
<I am sure if you ask around enough you will find opinions for and against every make and model out their.>
Maybe you guys could help me decide. I kinda would like a smaller footprint. Does Mr. Knop have some kind of special return of his reactor?
<I think you mean the return of the line to the US and not the return of the effluent from the reactor. They are available. Several of our sponsors carry them.>
Modified?
<There are new models available now.>
Something different that I might want to hold off on the others and wait for the return of the Knop brand?
<Keep looking around, gathering opinions, and make an informed decision.>
Thanks, Jamie
<You are welcome. -Steven Pro>

Calcium reactors
gentlemen how r u ? Here is what I' ve run into. I was just about to purchase a Knop calcium reactor for my 90 gallon and I am told they no longer sell them in the good old U S A . Is this true? and why? 
<Umm, actually are still being sold... site: http://www.knopproducts.com/
May seem biased... but the N. Am. distributor is Diana Fenner (we're related). Great products... well-engineered, constructed...>
I am now looking at different reactors and don't really trust anyone but you guys, everyone else out there is saying different things about different reactors.
<Like? Here's our recorded spiels: http://www.wetwebmedia.com/calcreactors.htm and the FAQs files beyond>
I was told the Aquamedic was a good one by one person, and another told me that the Aquamedic was not so hot and he liked the Precision Marine. Maybe you guys could help me decide.
<Mmm, better for you to sample more "end users"... through the BB's like Reefs.org, Reefcentral, ours: http://wetwebfotos.com/talk/ and others for folks who have more hands-on experience>
I kinda would like a smaller footprint. Does Mr. Knop have some kind of special return of his reactor? Modified ?
<I'll refer you to Di (I don't know)>
something different that I might want to hold off on the others and wait for the return of the Knop brand??? thanks Jamie
<Good questions... I'll also ask Jas.C to chime in... oh, and Antoine as well... they have units. Bob Fenner>

DIY Calc reactor
Greetings,
Do you have a diagram or pic of the DIY calc reactor your club has been making. I am part of a club here in Michigan ( http://www.wmmac.org ) and would like to entertain the idea of doing this project with our club as well. I have examined the Sanjay's calc reactor design and was wondering how is it modified from that?
Thanks A lot,
Jason

Re: DIY Calc reactor
There are some pictures on our club website...
www.marineaquarist.org
Click on the tanks section of the photo album. Click on the CaRx DIY link. This is an older version of the design. Bob Fenner took some pictures of the newer version. They were on his website...
www.wetwebmedia.com
I could not find them. He may know where they are. <<They can be found here: http://www.wetwebmedia.com/calcreactors.htm >>
The main difference between the design pictured and Sanjay's design is that the recirc loop is inside the reaction chamber.
The main differences between the design pictured and the current design are...
All the water and C02 taps are 3/16 ridged air tubing taps. The water and air flow rates don't require anything bigger. They're simpler too. Just drill a clean 3/16 hole and friction fit a bit of ridged air tubing into it. You can put a little two part clear epoxy resin around them if you are concerned about leaks.
The pump is the Rio 600 AV. This model has two venturis built in. One is
attached to the CO2 tap. The other is attached to a tube that runs up into the cap to scavenge C02 gas that has collected there. There has been some concern that the flow rate stirs the media up. I put filter pads on either side of the media.
Use clear tubing for the riser so you can see the CO2 being mixed in.
Use a 4" cap instead of a 4" coupler for the bottom. It is simpler and works fine.
<<Thanks for sharing - cheers, J -- >>

New calcium reactor
hey again, hope everything is going swell for you guys. <<Hello, my day is going well so far... how are you?>> I'm looking forward to checking out the new reef shark tank at the John G. Shedd Aquarium in Chicago, have you heard about that? <<I hadn't heard.>> Do you plan on visiting it? <<If I find myself in Chicago, for certain, yes.>> Anyway to my question, I am thinking about dumping the Kalkwasser idea and investing in a calcium reactor. good or bad? <<Good plan, although putting some Kalkwasser in from time to time, even with a calcium reactor, is a good idea.>> Preferably a Knop. <<Good choice.>> My tank is a 90. Have you any info for me on the Knop "C" , would that be perfect for me? <<I don't have any info 'for' you, but I have used this reactor myself and think it is an excellent, and simple package - would be perfect for your tank.>> And have you heard anything on that new one called the "S IV" with the pump and bubble counter inside? <<Yes I have, is the reactor I am using now on my 180.>> Really could use some direction here in choosing. <<The S-IV is probably too large for your 90... both are excellent calcium reactors, but the Type-C is your best bet.>> Also would you keep filter pads in the "Tidepool" sump? <<Sure.>> or is that just a nitrate factory? <<Actually, the wheel would be the factory... you are supposed to take out those pads and clean them about every one to two weeks. If you don't clean them, then yes - they will become factories for all kinds of bad things.>> My nitrates are about 20, "Salifert kinda hard to judge" Tank has been cycling for about a month with about 95 lbs. live rock. <<If you have a nitrate reading of 20, then your tank is now cycled. If you do pick up that reactor, please read this article before you set it up:
http://www.wetwebmedia.com/calcreactors.htm >> 
thanks , I know you will steer me right. Jaime
<<Cheers, J -- >>

Calcium reactor questions... effluent properties
Hello <<Greetings, JasonC here at your service.>>
I was wondering what is the best ph to run my calcium reactor with Korallith media. <<Ideally, you would want the effluent pH to be roughly 6.8, not any lower than 6.5... you should also measure the dKH of the effluent and try to tune the reactor to get that to about 15-16.>>
Thanks .
Bill Wann
<<Cheers, J -- >>

Knop C Reactor
Bob,
<<Hello, JasonC this time...>>
Recently I bought a 2nd hand Knop C reactor, and I am having a few problems. <<Ok.>>
I hope you can help. I have read your faq's and find them very helpful.
I did not receive setup directions and cannot find them anywhere on the web, this may be the source of all my problems. I have the input going to the bottom connector, and it is fed from a tee connection off the main return line lots of pressure as I accidentally found out). I am using ARM media. I am adding 20 bpm of CO2, and have the effluent line dripping 20 ml/ min. <<Hmmm... I'm rather skeptical of ARM media, it seems every container I pick off the shelf has a leaf or stick in it. Daniel Knop won't guarantee the results of his reactors unless you use Knop Korallith in it... but, back to the numbers you presented, I think 20 bubbles per minute of CO2 is too high for this reactor, try something between 10-15 instead. I forget the calculation on how many drops equals a milliliter, but your effluent should be coming out at between 2 to 3 drops per second.>>
The first problem is the return line stops flowing after several hours. I set the drip rate for 20 ml/min and after 6-7 hours it completely stops. I have a "needle" type valve at the end of the return line controlling the drip rate. I do not have the original valve. <<I don't think the valve type is your problem here. One of two things usually plugs the valve, either accumulated salt or calcium precipitation in the effluent line. I would think the latter is the cause in your case because of the amount of CO2 you are pumping in there.>>
The second problem I see is a large air pocket in the chamber just below the sponge supporting the media. This pocket starts out small and gets large after several hours. <<Yeah... that's excess CO2, try turning it down a notch or two.>>
Any suggestions/recommendations. <<You just got them all.>> Do I need to clean the reactor? <<No.>> change the "needle" valve to something else? <<No.>> replace the sponge that the media sits on? <<I don't think so.>>
HELP! <<Well.. always test the effluent before cranking the knobs up to 11 - I'd be willing to bet the effluent is at a dKH of over 20, and should really be in the range of 15-16 to have the best effect. Always take it slow and stray to the conservative side of things when bringing a calcium reactor to bear on your system.>>
Zander Gray
<<Cheers, J -- >>

Calcium Reactor Media
Hi:
I recently switched to Korallith reactor media, but have found that it is hard to dissolve and my calcium reactor now can't keep up with the demand, even with a high CO2 rate. <<Which size media did you use?>> (I've got heavy calcium users.) Lately I've been adding Kalkwasser around the clock for top off and I still can't get Ca levels above 380 ppm. kH is stuck around 10.5-11.0, but I can/have supplemented with Kent ProBuffer to get it up around 12 even 13, it just won't stay there unless I keep supplementing. I'm not sure what media I was using before, because I bought the reactor used and the old media worked great. It looked like it had crushed sea shells in it, but I hear
that's not a well-balanced media like aragonite. <<I've not heard that, and would certainly endorse using self-made crushed coral, shells, and the like - I mean... what are these things made out of anyway?>> From reading and looking around, I think what I'm after is CaribSea ARM because it sounds like it dissolves more easily plus has a good chemical analysis. <<Personally, I don't buy into all the recent hype about reactor media.>> What media do you recommend that dissolves the most easily? <<I use Korallith and have had no problems.>> I perform 10-15% water changes every week or two.
<<I would just add that I also don't subscribe to the philosophy of keeping calcium and alkalinity levels unusually high. The numbers you list are more than adequate, and are perhaps even higher than the normal, average conditions found in the ocean. I wouldn't strive for extra high numbers as they are really just unrealistic and itching for a problem like calcium precipitation. Cheers, J -- >>

Re: Calcium Reactor Media
Thanks for your reply. <<My pleasure...>> The media size is the only one that I know of that is routinely offered for sale by the various etailers out there. Each pebble is about 3 x 3 mm. <<Interesting... Knop also makes one that is about 1mm... is the size I use.>> I like your answer; it sure makes my life easier. But correct me if I'm wrong, my understanding is that natural seawater has a Ca level 425-450 ppm, <<I don't have the source right in front of me, but from my recollection the average is closer to 350-380.>> kH of 8, and a magnesium level around 1280-1300 ppm. Yes, my kH at 10.5 is elevated, but isn't my Calcium at 380 too low for long term health? I shouldn't be concerned about this? <<I don't think so... but you'd be able to tell more by the growth or lack of it in your coralline algae, stony corals and clams. Still, adding the Kalkwasser in addition to the regular input from the calcium reactor will help you move that up a notch or two if you must. Cheers, J -- >>

Knop Calcium Reactor
Hello friends,
<<And hello to you. JasonC here...>>
I recently went back to using my Knop calcium reactor; for about a year or so I had been using a Korallin Kalkreactor. Although Korallin is nice it just has too many fancy gadgets that eventually became a hassle and I found my self re-priming it once and twice a week. <<Interesting.>> So now that I'm back using the more simplistic Knop, I can't for the life of me find the instructions. Therefore I have yet been able to get it up and running, (as you can tell I have even forgot how to get it started). If you have any ideas where I might obtain an instruction manual or if you could shine some light on the beginning/starting-up process of the Knop, I'd really appreciate it.
<<Well, let's see... fill it up with media [bet you have that part done]. Fill up the bubble counter 2/3 with fresh water. Attach the C02 line to the bubble counter. Attach the feed and return lines to the reactor - feed goes in the bottom, return/effluent goes out the top. Fill the reactor from the tank - either with a siphon, dedicated pump, or T-fitting from the return pumps. With the effluent valve closed, turn on the pump and allow the reactor to circulate the water for 24 hours or until it clears up - will look like skim milk at first. Then, add C02 at a rate of one bubble every three to five seconds and open the effluent valve and allow to drip back into the system at about two drops per second. Test the effluent and your tank and then test again and again... that's really all there is to it. Like you said, the Knop reactor is simple and quite elegant for just this reason.>>
Thank you,
Rob
<<My pleasure. Cheers, J -- >>

Re: Knop Calcium Reactor
<<Good morning... JasonC back at your service.>>
Great and thank you for informing me on this subject. One more, the pump you say turn on and let run 24 hours or tell it's clear. Is this the dedicated pump I have that feeds the water to the reactor or is this both the dedicated pump and the main Eheim pump?
<<Well, you'd certainly need to fill the reactor, so that we'll call the feed pump - that would need to be on to fill the reactor. The circulation pump, the Eheim that is included with the reactor, that must also be turned on to being the circulation of the system water through the media, and eventually the CO2.>>
Thanks so much,
Rob
<<Cheers, J -- >>

Calcium Reactor
I am getting ready to  purchase a Calcium Reactor for a 125 reef tank.   I know nothing about them.
What brand and model do you recommend?
Thanks
Sam Mullinix
<I use the Knop reactors. I have had no problems with them.
Cheers, J -->

Clogged Knop reactor check valve
> Hello Daniel and all,
> Any suggestions for unclogging the check valve on the bubble counters that come with the reactors? I was thinking of a soak in some Muriatic acid.
> just Joe
> Reefkeepers mailing list
> Reefkeepers@seaplace.org
> http://www.seaplace.org/mailman/listinfo/reefkeepers
Joe,
Those check valves cannot just be cleaned by soaking in an acidic liquid.
It's a very sensitive membrane device opening at a pressure of 2 atmospheres. If the valve has already functioned before, it should not fail, they normally work "forever" and are very reliable. But if it has not been installed yet and did not work yet, it might be a "lemon". Whatever, just contact Diana Fenner and she will send you a replacement free of charge.
Only make sure that the test for function was not just a person blowing into the valve, because it is definitely impossible for a human to blow with that pressure (most of the check valves being sent back to us as a malfunctioned unit have been tested this way and work perfectly ;-)
Just contact Diana and she will solve the case. Right, Di?
Best regards,
Daniel

Calcium Reactor
Hello, and thanks for your reply. I am only running at the most 24 bubbles per minute of CO2 into the reactor. <<Only? The manufacturer's recommendation for this reactor is more like 15 per minute, so you are close to twice the amount you need.>> I have a Mag Drive 18 running my skimmer which I have a small (1/4" or slightly bigger) nipple teed off from to run my reactor with 3/4" PVC so I think I have plenty of power running the reactor. <<You can also have too much...>> The effluent was dripping at approx. 120 drips per minute at the time and I could not get the CO2 to get sucked through the reactor. I even tried tilting it at an angle to suck out the CO2 to no avail. Since reading your site I will be buffering my top off water with Seachem Marine Buffer and I already have been aerating with a CAP- 2200 with a venturi. I have a 60 gallon acrylic for a sump on an alternating light cycle. Down below I have numerous SPS frags, 2 plate corals, a very nice size Galaxea, small leathers, green star polyps a lawn mower blenny, a blue spot goby, emerald crabs, Astrea snails, a Niger Trigger( 1 1/2"), approx twenty pounds of pink flamingo from Carib Sea and 20-30lbs of live rock all lit by 200 and some odd watts of PC. Up top I have numerous large SPS corals along with frags, brains, a bubble coral, star polyps all over the place, some very nice size hammer and anchor corals along with a massive frogspawn( basketball in size), a smaller frogspawn( softball), very large plate coral(10 plus inches in diameter), a large clam, a 12" plus cup coral in diameter which is about 8-10" tall. Would pics help? I have about 150-200 lbs of live rock and only about 1-2" of live sand up top in the front half of the tank. I also have emerald crabs, 100 snails, a reef safe purple/orange lobster, 2 yellow tangs(6") a sailfin(6-8") a blue tang(6") and flame angel, coral beauty, six line wrasse, purple Pseudochromis, large lawn mower blenny, large yellow head goby, a Randall's goby and a clown that lives in my cup coral. I have Halimeda in both the top and the bottom. Main tank lit by (2) 400 watt metal halides for two hours in the middle of the day and 6 160 watt VHOs on incremental time periods . Do you see any thing that might be amiss? <<not really.>> Not enough sand to buffer the PH? <<could be, but live rock also fits this bill.>> Something else that would not allow the PH to rise above the 7.9 norm for the tank? <<Something in your husbandry of this system, methinks.>> Please let me know what you might think the problem might be. <<You need to re-examine what you are doing here... something about this system or the way you handle it is keeping the pH low. Supplementing with the buffer is a good plan.>> The LFS are no help and quite useless when it comes to saltwater problems. They are only there for money and selling anything anyone wants to buy. Thanks for any help you can offer, Jeff Reed
<<Cheers, J -- >>

Calcium reactor...
Bob, et al....
Quite awhile back, I remember you recommending something other than Korallith for a Knop reactor, but I can't find/remember what it was. Thanks. <<Hmmm... I use Knop Korallith, works fine for me... I've heard some rumors about leaching phosphate, but Daniel/Ralph are adamant that this is not the case. Certainly I've never had a problem with phosphates in the tank where my reactor runs. As for substitutes... crush your own coral, using dead coral skeletons, this can work just as well as commercial media - same stuff really.>>
Andy
<<Cheers, J -- >>

Low pH, high CO2, reactor design/maintenance
Hello, <<And hello to you.>> I have conversed with Mr. Calfo in the past about my low PH in my 180 gallon saltwater aquarium. I am very pleased with his help and straightening my situation out. My problem with my low PH still remains though. I just installed a Knop C calcium reactor two weeks ago with much frustration because of the large bubble of CO2 that kept getting stalled at the bottom of the chamber just below the blue sponge and under the PVC plate that it sits on. This would in turn stop any and all circulation of water through the calcium reactor. I finally figured out how to solve this bad design flaw. <<Ack! This is not a design flaw, you are simply pumping too much CO2 into the reactor in relation to the amount of water coming out of it. The problem you describe can be caused by three things which all work together, one - weak supply of feed water, not enough pressure. Two, slow drip rate out of the reactor, and three which works in tandem with number two, too much CO2 coming into the reactor. I've been running a Type-C for many months without this problem or modification.>> I took the reactor apart and had to forcefully pull out the round PVC plate that was in the bottom of the reaction chamber and shorten the PVC stand that it sits on by 3/4" of an inch so it now sits approx. 1/4" above the inlet tube to the Eheim pump. Any bubbles get sucked through and all was now running very well with no problems with the bubble under the blue sponge anymore. <<Fair enough...>> So after tweaking and fine tuning and reading through your web site I decided to install, inline, another reaction chamber to the Knop C that I already have. If I understand you guys correctly the second chamber is just another chamber after the first where the effluent from the first runs into the second from the bottom of the 2nd to the top where it then drips into the tank? Is this correct? <<Yes.>> I used a chamber from a used Kent 24gpd RO/DI unit that I had laying around that I was doing nothing with. It works rather well but the effluent still is only approx. .16 higher coming out of the 2nd chamber into the tank. The effluent out of the first is at 6.72(ppm?) and the PH of the effluent dripping into the tank from the 2nd chamber is 6.88(ppm?). Does this sound reasonable? <<sure.>> I am still a newbie to the calcium reactor thing. My alkalinity in the effluent is 14(?). I don't know if that's dKH or KH or what? I use the SeaTest kit from blue to green and get 14 drops. <<So the test should tell you what it is measuring - probably dKH.>> My effluent calcium the last time I checked was 320ppm using Salifert test kit. I use a Hanna PH hand held tester for the PH. My system PH will not come up above 8.15 during the day and tonight it was at 7.88 the last time I checked. My system alkalinity is a constant 12 with the calcium reactor running. The only way to get my PH above 7.9 during the day or night is to add Seachem Marine Buffer on the order of 3-4 tablespoons in a tall glass of water mixed for about 5 minutes. 
<<Well... you have some compelling reasons to not be running a calcium reactor at the moment. If you were having pH problems before, the reactor and all it's various modifications isn't going to help at all. I would carefully examine your system to determine why it is so hard to keep the pH up - do you buffer the water you use for top-off? Do you have a sump with photosynthesis going on? You could move this to reverse-daylight time to help boost the pH at night. A favorite of Anthony's is to do small Kalkwasser additions [naturally high pH] first thing in the morning. You have many options, but running a calcium reactor, who's effluent is by design always below 7.0 is going to give you fits. Consider tackling the pH problem first... if you have calcium-hungry occupants, supplement with a two part solution until you get the pH under control, then go back to running the calcium reactor. Cheers, J -- >>