Calcium Reactor Question  - 12/07/06
Good Morning Crew!
<Dave>
I have a couple of questions regarding my Knop S-IV calcium reactor.
The reactor seems to not be circulating the CO2 as well as it should, and therefore not melting the Korallith media.
<For browsers this is the CaCO3 media by Knop>
  How often should you replace the coarse blue filter pads that are at either end of the reactor?
<Don't ever need to be replaced>
Here's my situation, I've had my reactor set up for about 10 months now on a tank that was set up at the same time.  Other than 175 Lbs. of live rock in my 150 gal tank, and a few coral frags, I don't have much of a calcium load.  Animals seem fine, but for the first few months I was able to maintain my calcium and alk with a CO2 rate of 30 BPM, and a drip rate of 3 drops every 2 seconds.
<With an effluent pH of?>
I was using the larger coarse 6 -10mm Korallith reactor media.  My calcium was 390, and my DKH was 9 -10, and my ph was 8.2 - 8.3.  My effluent measured a PH of 6.7 - 6.8,
<Ah, I see>
DKH of 36 and calcium was 500   
<Mmm, okay>
After about 4 months I made an adjustment by accidentally to the needle valve, and had to go through the slow readjustment process, but I wasn't able to maintain the same levels as before.  I started off slowly with the same PH and drip rates as before, but the effluent still wasn't strong enough with a DKH of 16 -18 and a calcium of 450, nor was I able to maintain my calcium and alk levels overall.  I seem to deplete about 1-2 DKH/day and 25 or so of calcium per day, and the effluent levels weren't keeping up.
<Mmm, four months? You very likely just need to replenish the media... or at least shake/consolidate and add to it>
Now, after slowly adjusted the reactor to a drip rate of 5 drops/sec and 120 BPM of CO2 with a PH of 6.6-6.7, and changing the media grain size to medium (3-4mm) am I able to maintain my calcium and alk demand per day, but effluent DKH is still light (about 16-18 DKH), and calcium around 490.  My overall tank levels are 7-8 DKH, ph 8.10 - 8.20, ca 370, and nitrite, nitrate, phosphate = 0, <1, .4.   
<This is fine... I would not change a thing here>
I see lots of bubbles collecting underneath the blue filter pads in the very bottom and upper middle of the reactor, and there's a large bubble that collects under the lid at the top which seems normal, but don't remember ever seeing bubbles underneath the blue coarse filter pads.
<This is most likely due to impurity/ies in your carbon dioxide... Nitrogen, Oxygen... less soluble... look to "higher grade" (more pure) CO2 next re-fill>
It seems to me that the reactor isn't circulating the CO2 as well as it should.
<It won't with air trapped in it>
I've tried rinsing out the filter pads a couple of times, but CO2 still accumulates at the underneath side of the pads.
<Not CO@... this gas is very water soluble...>
  I've also tried turning the reactor upside down and right side up again the get the bubbles to interact with the media some more,
<Good>
but this creates a lot of precipitate to be free floating again, which in turn saturates the blue filter pads in the second chamber (CO2 filter).  I've tried just rocking it back and forth to get the bubbles to enter the pump which creates a lot of swirling bubbles in the pump chamber.  Something is amiss, can you suggest anything?
<The CO2 purity>
Should I try dropping the effluent PH to 6.4?
<No, I would not>
  Should I replace the blue filter pads or soak them in vinegar?
<... you could, but unnecessary... I'd just rinse them off/out vigorously on the occasions you have the unit open>
Should I try the fine reactor media?
<Mmm, I would stick with, use the 10mm nominal diameter... 1082 call-out if memory serves... I've carried several tons of it about...>
I just want to be able to obtain the same effluent levels I had when I first set it up.  I'm also waiting for ph regents so I can calibrate my Pinpoint PH probe just to make sure of my values.  
Thank you,
-David   
<Do ask the gas service if they have other grades of CO2... I do believe this is your principal issue here. Bob Fenner>

Toxic tank, Contaminated Calcium Reactor Media    2/12/07
  I have had toxic tank syndrome for 8 months now.  My pulsing Xenia starts to turn black in less than 24 hours.  All SPS corals had to be removed from my 180 gallon 5 year old tank.  Lost some fish, scooter blenny, mandarin, Rainford goby.
<Yikes... so, what have you done re the toxicity?>
    To make a long story short, I changed water like crazy, searched everything for a metal contamination.  Could find nothing, so I emptied the system completely.  Cleaned it all out, replaced the sand bed, all rock, everything out, and refilled with natural sea water.  After a week, I put a piece of pulsing Xenia in last night, and this morning the polyps were starting to turn black.
    I got mad, again, and the only thing I had not done was to empty my calcium reactor.  I put the media in a bowl and searched it.  Using a magnet, I found small flakes of metal of some sort, laced through the media!!!!!!!!!
<Yikes...>
  I have not idea how it got there!  Not from me!  I won't mention a brand name here.
<I wish you would... My wife, Diana, used to distribute Knop Products in N. America... their Korallith was/is very pure...>
    I will do a 100% water change as soon as possible.  I can not afford to change the rock and sand bed again!  What further steps should I take?  Carbon?  Poly filters?
<Yes to both of these... this should do it>
Will my new rock and sand be ok?
<Very likely yes>
There are no fish or corals in the tank st this time.  All have been moved to other systems.
  Help
  Richard
<Thank you for relating your experiences... Will save many others huge headaches and grief. Bob Fenner>

- Calcium Reactor Adjustments -
Hi Bob and Crew,
I have had a KORALLIN C-1502 Calcium Reactor for about 4 months. It was purchased new. I have tried repeatedly to adjust it to the proper levels of CA and DKH. The Korallin web site is of little help as are their instructions. I have kept a log of my settings and results. They are as follows and my readings are taken 2 days after an adjustment.
DRIPS    BUBBLES    CA     DKH
20            12    380    14.1  
24            12    380    12.5
40            20    350    13.4
28            16    360    12.2
60            24    370    12.8
40            20    360    12.5
28            20    370    12.5
<I'm guessing the bubble numbers are per minute?>
With most all of these settings except the lowest I get an air lock and must bleed off the CO2 every 12 hours. I don't understand how to create the proper adjustments as I can't get the CA above 380. Do any of you see anything obvious that I'm doing wrong? <Perhaps - I would be shooting for a rapid drip rate - about three drops every two seconds. CO2... probably best around one bubble every four to five seconds, but this is the adjustment I'd tweak. I'd get the water coming out the reactor as consistently as possible, and then adjust your CO2 to bring the pH of the effluent to about 6.7 - 6.8, and a dKH of roughly 16-17. After a week or two of this, you should see more consistent calcium levels.> I know it shouldn't be this difficult or no one would purchase this brand of reactor. I have a 110 gal. with soft corals and fish. Filter is a Euro-Fil-2 with the protein skimmer that came with it. The reactor media is only 4 months old. The media label says it's Korallin Natural CACO3 KTK ORCCM . Tank PH stays at a steady 7.9 at night and 8.0 at lights off. Effluent measures with a CA of 750 (if that's possible) and a DKH of 6.0 I am using a PH meter which is calibrated bi-weekly. Should I replace the media as none of my settings get me over 400 CA? If so do you recommend the brand A.R.M. Calcium reactor media or some other brand? <No, I'd use anything BUT A.R.M - just too impure for my tastes. I'd use the Knop Korallith - is very consistent quality.>
Do any of you know if Korallin has a west coast rep? <I believe they are distributed exclusively by Bayside Aquarium which is in Anaheim.> Their web site makes no mention.  Thanks in advance, Dick
<Cheers, J -- >

- Calcium Reactor Adjustments, Follow-up -
Hi J,
Good morning. <Greetings.> Again I want to thank you and the crew for all the help you give reefers everywhere. <My pleasure.> After this I'll give your suggestions a try and get back to you with the results in a couple of weeks. <Good, would like to know how it's going.> Korallin should ask you and your team to write an instruction booklet. :-) <Perhaps... but I won't hold my breath.>
Thanks again, Dick
<Cheers, J -- >

- Calcium Reactor Adjustments, Follow-up -
Hi Gang,
I just noticed an error in my statement. My effluent measured CA 750 and a DKH of 64. Not the 6 as I noted.  Thanks again, Dick
<No worries, but it does seem to me that you are trying to pump too much out of this reactor - again, you should shoot for something more in the range of a dKH of 15-17 on the output side of the reactor. Calcium will be more readily available to the system at this level.
Cheers, J -- >

- Calcium Reactor Adjustments -
Hi J,
I have set my bubble rate and drip per your suggestions. I suspect that my tanks DKH is going to rise. <I don't think it will get too out of hand.> The weekend is coming up and I doubt anyone will be online. <Oh sure they will be, myself included.> If my DKH rises to 15 or more in the tank should I abort or keep going until it levels out. <Just turn off the CO2 via the solenoid... but I don't think you'll have much trouble.> What level of DKH do you think should alarm me to stop? <Over 15, 17 max... but this will depend also on calcium - keep an eye on both.>  Thanks again, Dick
<Cheers, J -- >

- Calcium Reactor Adjustments, Follow-up -
Doctor J, <Hey, I like the sound of that... too bad I'm a white boy that can't jump like him.>
Your info is working. <Excellent - glad to hear that I was able to help.> Thanks for the tips. So far my DKH has only risen slightly after 24 hrs and my CA is now rising. It's at 380 right now and I'm not having to bleed off excess CO2. Will check again tonight. <Sounds good.>  Thanks for everything, Dick  <Cheers, J -- >

S-IV reactor
Diana, I emailed you yesterday and have not heard back from you.  I do have a quick question about the reactor.  Is the internal bubble counter subject to the pressure that builds up inside the reactor?  I have a new dual gauge regulator setup with a very expensive needle value, and no matter how hard I try the bubble rate will not settle down.  I can set the rate to say 25 bubble per minute, and twenty minutes later the rate has changed, it will go either way, up or down, but never stays the same with your supplier.  You can't set the reactor up without having a constant bubble rate.  Is it possible that this reactor is more damaged than I first thought?  Have other customer complained about this problem?  I need a response quick as I am trying to make a decision about whether to keep this reactor, or send it back to Marine Depot for a refund.  I assume since I haven't heard from you that you haven't sent the check out.  In either case If we can't solve this problem, I will simple return your original check, as I would never cash the check if there was a problem.  Regards, Tim Roberts
<would first switch out your needle valve here, the tank pressure and flow through your regulator are very likely static (fine). Bob Fenner>
Hello... JasonC here. Have seen this problem before and is typically caused by a leak in the CO2 plumbing... either a crack in the tubing, a leak in/near/around the regulator - if it has it's own bubble counter, this is a common place for the leak to occur. Would examine all these things closely... between the CO2 tank and the reactor all those fittings need to be air tight and plumbed with CO2-proof tubing.
Cheers,
J --

- Calcium Reactor Problems - 
Jason C, thanks for the reply. <My pleasure.> When I replaced my old gauge set with a new set, a set with a working pressure gauge which goes from 0 to 15 PSI (why old one went from 0 to 150) , I noticed that the pressure on the gauge would continually drop. <Sounds like a leak somewhere...> I set the gauge five times last night. I would set the working pressure to 10 PSI, and a few minutes later the gauge would read 8 PSI, so I would readjust. I am thinking I have a hairline crack in the tank valve. <Or somewhere close...> A leak in the gauges, or after the gauges would not effect the working pressure. <Actually, the working pressure is somewhat reliant on back pressure in the rest of the 'plumbing' between the CO2 supply and the reactor... have seen this exact behavior caused by a crack in the CO2 proof tubing which is not infinitely elastic - can be cracked by stepping on it or too tight of a turn radius.> Remember I have had this same problem with two different gauge sets from two different manufactures. <All the more reason to make sure you don't have a problem in the lines.> The odds of having two regulators, both defective, with the same problems, are really small. What do you think, am I on the right track? <Perhaps... would be diligently checking in all possible places, not just the ones that make sense.> 
Thanks, Tim 
<Cheers, J -- >

- Reactor Trouble, More Follow-up -
Jason, thanks for your help.  I am not trying to disagree with you, I am just grasping for straws to get the reactor to work. <No worries.> The air line I used is supposed to be CO2 safe, however, I will replace it with some tubing that came with another reactor I had.  Please don't misunderstand me, you are the expert, and I appreciate your time. <I am hardly an expert... everyone's experience is different.> I didn't get the instructions or the tubing that was suppose to come with the reactor. <Bummer.> Diana is sending them to me this week. <Excellent.>
Thanks, Tim
<Cheers, J -- >

- Calcium Reactor Problems -
Hello Robert,
<Hello, JasonC here in his stead...>
I bought your book "Conscientious Aquarist" and enjoy it very much. Recently set up a DIY calcium reactor and had a few questions.  Was hoping you might be able to provide some guidance or refer me to a site for advice. <I will do my best.>
Questions:
1.)  What's the normal break-in period and what exactly does that mean? <There really isn't one - what is breaking-in is you - getting used to how the various adjustments work in conjunction with your tank.>
2.)  Seem to be having difficulty getting effluent PH to drop below 7.0 with CO2 rate at about 15-20 bubbles per minute and effluent dripping too fast to count, but not streaming.  Is this related to a break-in period or do I need to increase CO2 or decrease effluent rate? <Either but not both - I would leave the CO2 as it and reduce the drip rate exiting the reactor.>
3)  Are these reactors supposed to work under some pressure? <Only the smallest amount.> seems by adjusting input rate and effluent rate, it will eventually equalize anyway. Yes/no? Does pressure affect amount of dissolved CO2 in the chamber? <Yes.>
4)  Measured calcium level of effluent and it seems to be no higher than the water in the tank itself.  I expected to see a much higher level.  Suspect this is related to PH level in chamber not being low enough to dissolve media.  Correct? <Correct.>
In essence, how do I get this thing tuned properly and how long should I expect this process to last. <Please read an article I've written about this exact topic:
http://www.wetwebmedia.com/calcreactors.htm >
Starting with low calcium levels in the first place about 260.  Could this have something to do with it?  Tank PH ranges from about 8.0 to 8.2 using Pinpoint monitor, temp ranges from 76.5 to 78. Not much in the tank, other than live rock, live sand, some cleaner critters and a lone Yellow Tang.  About 220 gallons including sump and refugium. Want to get things just right before adding any more critters. <Do read up.>
Thanks for your help.
Regards,
Julio
South Florida
<Cheers, J -- >

- Calcium Reactor Problems, Follow-up -
JasonC, <Hi.>
Thanks for the feedback and article. <My pleasure.> See below. <Ok.>
Well, I finally have this thing tuned and, I think, working properly. Bubble rate of about 40 per minute and effluent rate of about 60 per minute results in an effluent out of the second chamber with calcium level in excess of 500 ppm and alk of about 16. <How about the pH of the effluent?> Both of these are at the maximum ranges of my test kits.  So I feel good about where I am at this point.
On the other hand, I'm confused.  After about two weeks of the reactor running 24/7 at the above effluent parameters, I've seen no change in the calcium level of the tank (about 270 ppm). <It's going to take a little longer than just two weeks to actually see this thing bear fruit.> Alk/dKH has gone up considerably from about 8 to just over 13, but calcium level isn't doing anything.  Any thoughts? <Patience.> Magnesium level is about 1200, which is a bit low.  I've read this can influence the calcium levels. <It can.> So here are my questions:
1. Do you think Magnesium at 1200 is the cause of my problem? <Not necessarily, but could be the result of the media you are using in the reactor. A good media will help supplement this.>
2. Do calcium reactors have the ability to raise already low levels of calcium, or do they simply replenish what is consumed by tank inhabitants? <Depends on how it is adjusted and sized to the tank.> I only have live rock at this point in time.
3. Is the high Alk/dKH now part of the problem? <It's a limiting factor, but the byproduct of the calcium reactor is calcium carbonate so there should be a good amount of calcium about. You might want to try another test kit.>
4. Where do I go from here? <Forward, onward.>
Yours truly going insane, <No worries.>
JT
<Cheers, J -- >

- Calcium Complications -
I have had a saltwater tank for over 10 years. It has been an up & down battle all 10. I recently decided to go for it and purchase some good equipment. New Hamilton Protostar 4' light. 2 x 250w HQI & 2 96w 7100K power compacts. I made my own calcium reactor that is working quite well.(3"x20") I just added Korallith media to it (removed old media) because I was getting such a high KH 28.8 PH 6.8 calcium 460 out of the reactor. Now, with the Korallith, my KH is off the scale calcium 460 PH 6.7. I am using Salifert test kits, brand new. Bubble rate co2 1 every 4 seconds, drip rate 1 drop every 2 seconds CO2 shuts off with the lights. <I'd increase the drip rate out of the reactor - perhaps two drops every three second.> I have had trouble getting a consistent drip rate, any ideas on a good valve? <Probably not the valve but calcium precipitating on the tip of the valve - turn down your CO2 for a little while, let a little more water out of the reactor.> I'm getting frustrated. <Well... try to save it for later, calcium reactors generally take a good deal of adjustment before they work just right.> From what I have read, there is no way that I should be getting these kind of numbers out of this set up. <Oh no... it's very easy to produce these results - your reactor needs more adjustment.> I have gotten the drip rate up, but the PH out of the reactor goes up to 7.0 or higher. <That's OK.> Why is my KH off the scale? <Because calcium reactors are really alkalinity reactors, with calcium being a by product.> My tank PH is 8.1 during the day, 7.9 at night. I have new PH controller, regulator with solenoid valve. All of this equipment is new. The reactor is working great. It can pull the co2 all the way down through the pump. I have a couple of the SPS frags that are going down for the count. Others look good, but little if any growth. I have some LPS coral that are doing good, and My leathers are OK too! I do have some coralline popping up, most of my tank was void of it before I started the reactor. I have had troubles keeping the PH up. Things are better but this off the scale KH has me bothered. <It should be expected - what is the alkalinity of your tank - that is the more important number.> If the KH is this high, My PH should not be a problem? <Could be other items - perhaps dirty gravel/sand pulling down the pH - look for all possible sources.> I think that I am also getting SNOW. <Then turn off the reactor for a while - run a full round of calcium and alkalinity tests on the tank - this should be telling.> White yuck laying around the tank. I change 4 Gallons of water every week to try & keep it under control. 70 gallon tank, 10 gallon sump, chiller set at 80* heater at 78*, protein skimmer, small NNR in the sump. My nitrates are zero, I quit testing it because it has been zero forever. RO/DI replacement water new setup) Instant ocean 1.024 SG. What's up with my reactor????? <It needs more adjustment from you.>
Jeff
<Cheers, J -- >

- Bubble Counter Problems -
I'm having a problem w/ the bubble counter on my reactor filling up w/water. Water is dripping in slowly but is coming in from the reaction chamber. This is apparently an older design of the bubble counter as the input and output are both on top. What can be done to stop this? <The only time I've seen this is when there is a leak and/or lack of pressure in the CO2 supply to the bubble counter. Most often this can be observed when power is lost at the solenoid and the CO2 supply is cut off. I'd make certain your CO2 regulator is set to about 10 lbs and that there are no leaks in the CO2 supply.> I only need it 2/3 full and it's completely full as is. I also have water dripping out of the top. <Should probably remove this fitting and put some pipe tape on it - any leaking at all in the CO2 supply to the reactor will cause problem similar to those you describe.> Your assistance would be much appreciated.
Thanks.
Sincerely,
Mike
<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 -- >> 

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 Woes
Hi there guys, whoever is helping today.
<Anthony here in your service... >
Here is my dilemma with my calcium reactor. I have a 45g reef tank, with 1 175w metal halide, 2 28w actinics and one custom SeaLife PowerQuad with 96 watts, which brings me to about 7 watts per gallon. I have some pieces of Acropora and other hard coral, a few softies and 4 clams. I was getting tired of dosing part a + b of whatever calcium so I bought a K2R reactor with Carib sea arm media. After about 1 week I build a nice second reactor to bring the pH back up a little before the effluent drips int a small container that overflows into my sump. I keep my effluent at pH6.8 via controller. My dKH is way off the chart, around 22dkh. 
<whoa!>
In the effluent it was around 45 at first,
<Biggie-sized Whoa!>
Then I started to set the effluent to more flow instead of dripping it,
<hmmmm?>
and the effluent dKH came down to around 30, still no change in dKH in my tank.
<too much bled in at fist and unused>
Calcium in my tank does not seem to rise because of high dKH. It is only around 250 to 280 at best.
<indeed, the calc/alk ratio is skewed>
effluent calc is around 300 to 350. I am at a loss here and want to know what else I could do. I don't want to dose anything, but I do dose calcium to keep the levels up a bit.
My questions are, how do I get the dKH lower, I did water changes and top off with ro/di water,
<Agreed... dilute the dKH with a large water change but follow up with a slower drip through the reactors...any flow described as a stream rather than a drip is too fast. Also, you may use Calcium Chloride (liquid calcium/turbo calcium dry) briefly to get your calcium up to a more traditional level (after the water change and drip adjustment...even 350-400 would eb great at this point.>
but I don't know what else I could do. The system has been running for about 4 weeks and no improvement in calcium.
I have to say, my corals look great though, my clams seem happy, not me though, I want the calc up to 450, the dKH to 12.
<simultaneous high end levels of calcium and alkalinity are not realistic for most systems...in gross terms they can even be mutually exclusive (causing crystalline precipitate "snowstorms" of which you are at dangerous risk with your high dKH>
am I getting impatient too soon or are there any tricks. 
<quite frankly, you either didn't get good directions with your reactor or you didn't follow them. You streamed too much carbonate into your system and it will take some serious dilution to get it down. Imagine if your dKH was 24 and you did a 25% water change... even with demineralized water (dangerous!!!) you would only bring it down to 18 dKH, and so on... It will take time and dilution. The effluent water should exit at the rate of a drip and not a very fast one at that>
Magnesium is around 1350. I know I can't keep the dKH that high for long, but I don't know what else to do. I appreciate all your help and I am glad that Bob has great friend that are willing to share their knowledge with us. Please tell Bob I said hi and I am still waiting for him to come to Los Angeles to get his free haircut (he knows what I am talking about, hahaha). And if you guys are in town same offer to you, the least I can do.
<Wonderful<smile>...and thank you!>
By the way, I will probably go to Interzoo in may, since I have to go see my parents and friends anyway, and that's where I grew up for 25 years, in Nurnberg. My parents live about 2 minutes away from the convention centre. I hope to meet you guys there, I'll owe you a few beers for all the good advice. SASCHA
<Bob, indeed will be going... but alas, Steve and I will be back here helping to run the site. But not for a lack of gracious invitation by Bob. I will look forward to sharing some food and intoxicating libations in LA with you. Kind regards, Anthony>

Alkalinity and pH Control
Bob:
<Steven today.>
Recently I purchased a large calcium reactor secondhand from a local marine store (MTC Pro-Cal). I set it up on my 58 gal. reef (small in size compared to the reactor's capabilities!). I had it running for a couple days with very low input into the tank in order to avoid a sharp change in pH. However, within a couple days I noticed that most of my soft corals had closed up, with one torch coral looking like the tips had been burnt off! I also noticed a dead shrimp and some snails that were not moving, starfish with holes (lesions) in them, and mucus sloughing off the corals. My purple Montipora bleached out in a day. I am afraid I have done irreparable damage to the tank inhabitants. The catch is, I cannot determine the exact cause. The fish have not been affected. I did a partial water change with little improvement to the inhabitants.
At the same time that I started the reactor I also added a product called "Stop Parasite", because of an Ich outbreak. The manufacturer says this product is completely safe for reef aquariums, and it can be added directly to the aquarium. I only added one dose (less than 1 teaspoon) and stopped because of the reaction of the corals. [By the way, would a UV sterilizer be the best method for eradicating Ich?] I placed activated carbon back into the sump.
In any case, because these two things occurred simultaneously, I am having difficulty assessing which one caused the problem.
I have a pH monitor on the tank. I noticed the pH range to be between 7.9-8.2 (could have been a time I didn't noticed a dramatic drop, but I have been adding more buffer in the hope to preclude a swing in pH). I just measured the alkalinity in the tank and it seems to be good (4.0 meq/L or 11.2 dKH). Could a dramatic increase in alkalinity cause this type of reaction of the invertebrates? The alkalinity in the tank before I set up the reactor was around 2.0 - 2.5 meq/L. As a note, I haven't calibrated the pH meter since I bought it (I know, a bonehead move). I will do so shortly.
<Your information about pH is completely useless when measuring with an uncalibrated machine. It is utterly impossible for me to say if the readings are accurate, significantly lower, or higher than the numbers you gave.>
Do you know anything about this "Stop Parasite" product that is supposed to be so safe in reef systems? Aside from purchasing a UV sterilizer (another expensive purchase), I have tried unsuccessfully to get rid of Ich in my tank. Could a dramatic swing in alkalinity cause an "acid-like" reaction where the corals and other invertebrates appear "burned"?
<I do not know which caused the problems in your tank. Whenever first hooking up a calcium reactor it is imperative that you watch the calcium, alkalinity, and pH very closely for the first several weeks until you have the unit dialed in correctly. Secondly, I would not use any Ich medication on a reef tank. It is much better to quarantine all new arrivals prior to putting them into your main display. Unless, the Ich broke out and you have not added any new fish for several months. Then you may have even more problems.>
Thanks for your response. Tim
<With more and accurate information, perhaps I can be of more assistance. -Steven Pro>

Bubbles of CO2
Hello, Bob
For a long time I have been observing the accumulation of bubbles on the rocks in my 125g tank. In the places, where there bubbles gather,
<I'd say, "coalesce"... gasses always forming, dissipating... but under some conditions...>
coralline algae stop growing and brown algae, which aren't slime algae <Actually, very likely this is a or a mix of blue green, aka slime algae, aka Cyanobacteria... Got a microscope? Have some micrographs, explanations of how to discern "real" algae from BGA on the site: www.WetWebMedia.com under the term "BGA".>
and tightly stick to rocks, appear. What can I do to stop it? 
<See the above citation under the Marine Index... not hard to turn the system in your favored direction>
Calcium level is high, about 460, kH - 8, pH - 8,2-8,4, NO3-0, PO4-0. I use the Aqua Medic calcium reactor. It's set for approximately 60 bubbles of CO2/minute and 60-70 drops/m of the effluent. The reactor is filled with hydrocarbonate. As I have two Tunze pumps (1 pomp- 2400l/h), gas exchange ought to be good. 
<Your readings look good... but... oh, I see the question coming below>
Is it possible that it is the excess of CO2 that creates bubbles?
<Yes... do you know the pH of the effluent? I would not have it lower than 6.9... and would (among other things... like using a lighted sump, macro-algae...) cut back, reduce the amount of CO2 bubbling accordingly... and maybe look into more soluble carbonate source. A softer aragonite might be better>
I do partial changes of water (RO) every two weeks
(10%). I would be very thankful for your advices.
With regards
Krzysztof Tryc
Poland, Warsaw
http://www.astercity.net/~lumen
<Please look over the site, measure the pH of the effluent, reduce the input of carbon dioxide... The bubbles are not CO2, but from driven metabolism of organisms in your substrate. Bob Fenner>

Calcium reactor effluent
Mr. Fenner
I hope you're fine.
<Yes my friend, thank you>
This time I ask you for a comment...advice, about a fact concerning my calcium reactor.
-The reactor effluent comes out through a 5mm. int. diameter flexible plastic tube with more or less 5 cm length. If I collect and measure the liquid PH at this point, let's say I obtain a 6.7 value.
<A little low... would keep at 6.8 or slightly higher>
-In my system, that tube extends about 1 meter and drains in the sump. If, at the same occasion, I measure the PH in this point, the value is 7.4
-And..... again at the same occasion, the PH inside the reactor is 6.5
<Okay>
Is the lost of CO2 during the tube passage the cause of this PH increase ?
<Largely, yes>
If yes and if it is something to avoid, should I short-cut the tube? For me it's easy making drip the CR effluent in the refugium ( macroalgae) or in the 25 liters recipient that contains the skimmers. All of this recipients are draining in the sump.
<Hmm, yes, better to cut, run the tube shorter... better still to make sure the effluent has maximized amounts of biomineral dissolved in it... I would slow the bubble count down a bit, recirculate the mixed water in your reactor contact chamber if this is possible in your make/model of reactor...>
For water changes I use fresh and clear.....macroscope!..... natural seawater. What can I do in order to minimize eventual mal-effects ?
<Store in the dark, make regular water changes after it's stored a week or two... and possibly add a bit of buffer to it... If it were mine, I would be tempted to just use synthetic water...>
I appreciate very much your opinion about the described issues.
<Glad to help. Bob Fenner>
Best regards and thanks
Flávio Ribeiro

Thanks for you help
Mr. Fenner,
<Call me Bob>
I just wanted to update you as to the problems that you helped me solve in my 300 gallon reef tank...and to thank you for the assistance.
<Okay>
I asked for help with my shy Copperband and my Cyano-bloom and you were absolutely right on ! You told me that in time the butterfly would come around and he is now eating frozen food as well as grazing over more of the tank. Now he is my most beautiful fish and he actually comes to me for feeding now....a long way from that beaten up, ulcerated fish i bought a half year ago. I am so glad he is healthy and happy and that he is not hiding anymore.
<Me too>
Then you told me NOT to use antibiotics for the Cyano. Instead I just turned down the CO2 feeding my calcium reactor and the Cyano is almost gone....I am also in the process of acquiring Caulerpa and other good algae to plant in my sump along with a reverse lighting schedule from the main tank (I will hopefully get some time this weekend as long as the wife doesn't have any plans for me !). 
<Yikes...>
Hopefully this will give me a more constant pH and will keep the nutrients low so that i can avoid another bloom.
<It will my friend>
My tank looks great without all of that Cyano and my gorgonians are lot happier.
Thanks again !
Chuck Spyropulos
<Very glad to hear of your success. Bob Fenner>

Low pH using Calcium Reactor
Hello Bob,
We have a 150 gal reef tank with a 40 gal sump (1/2 of the sump is a refugium).
<Good size, idea>
We purchased a Knop HD Calcium reactor using Knop Korallith media about 2 mo. ago and just recently have seen an increase in the calcium level (in tank and effluent). However, the pH in the tank is very low. It ranges from 7.94 to 8.08. 
<This is not "very low"... indeed, it's higher than most places on the world's reefs...>
I've read in your emails to others to keep the effluent pH at 6.8.
We've been keeping the effluent pH between 6.3 - 6.4 to keep the Calcium level in the effluent over 600, which we were told it's supposed to be. 
<Not IMO>
We had the effluent pH higher, but that resulted in a lower calcium level. Our calcium level in the tank  now is only 350. We realize the low effluent pH is keeping our tank pH low. 
<Yes, likely>
We have the bubble count high approx. 130/min, water flow is 3l/hr, alkalinity is 5.5. Our corals look  great and the xenia's are spreading like wild fire, but I don't think they'll survive long with such a low pH.  What can we do to get the pH higher and to maintain a high calcium level as well?
Thanks in advance.
Sherri
<This may seem like a simple to the state of flippancy suggestion (it is not), but do just look into and use  a more suitable material to "melt down"... There are a few other possible "issues" at play here (resultant mis-interactions from concurrent or "old" use of supplements, a proportionality problem  with another alkaline earth material (Magnesium)... but do just look into... Aragonitic materials, like  CaribSea's... and give them a go. No intention/need to be mysterious here... these are composed of  different mixes of biomineral and alkaline materials... some more soluble than others... Next, if this doesn't do the "trick" for you, we can discuss the use of expedients like baking soda... other adjuncts.
Bob Fenner>

Calcium Reactor/algae
Hello Bob,
I have now had a calcium reactor on my 30 gallon mixed reef for about 4 plus months. During this time I haven't added anything other than PhosGuard biweekly with 10% water changes. The corals look great and coralline is growing rather well. But green hair algae is growing like crazy! I had a problem with this before (prior to having a calcium reactor), and was able to clear the tank of it. Although I have noticed that the green hair algae I had before was long and stringy, where the green hair algae now is short, and looks like tuft's of hair. I use Knop Korallith media, and originally had my effluent PH running around 6.3-6.5 for the first month. After speaking with you I started keeping the effluent PH around 6.8, but still no change in the green hair algae's growth. I use only RO water and I keep lots of live rock, hard and soft corals and clams with 4 small fish and a Algae Blenny. Also keeping many small crabs and shrimps, including 4 Emerald crabs. 
<An algae blenny and four Mithrax in a thirty... should be enough...>
I feed maybe a pinch of San Francisco Bay Brand, Sally's frozen brine shrimp every 3 to 4 day's, and have even gone almost 2 weeks without feeding, and still green hair algae grows. I run three 36in VHO lights 2 white, one blue, 9 hours a day. I have tried many times to keep green macro algae, but my Tang and Emerald's devourer it, and I had no luck with it in a (24hr lit) refugium/sump. Could you please help me in figuring out what the problem is here.
<No luck with a refugium? Would like to know more here... a hang on type? What happened?>
Your knowledge and patronage is always appreciated.
<As are your kind attentions and input... You are doing about all I would/do .. you're not adding anything else? I would use activated carbon once a month... Bob Fenner>
Thank you, Rob

(DIY) Calcium Reactor Questions
1. If you over drive your calcium reactor does the excess calcium precipitate on the water surface or attach to everything like Kalkwasser drips?
<Mmm, some calcium reactors, various feed stocks can be made to do this... but not practically>
2. What is the maximum saltwater can hold?
<The maximum what? Calcium? Several hundred ppm.>
3. Does salinity (1.019) or water temperature (76-80) play a significant factor?
<In saturation, introduction of biominerals (alkaline earth elements)? No, not "significant" in hobbyist/husbandry terms>
In preparing for a larger main tank I have built a six foot tall calcium reactor. 
<Six foot tall? Unnecessary. Was at a local marine club meeting a few days back just to give you an example. The owner had a 1,200 (twelve hundred) gallon system with a two foot high Knop unit...>
Poured 50 pounds of Geo Marine in it then I pushed the affluent
<Is it rich? Effluent likely>
PH down into the 6.5s while maintaining a fair water flow.
Within 24 hours I now have what feels like sandpaper grit accumulating on the water surface in the sump. Is this related?
<Yes>
Fish seem OK. Has anyone else felt this on the water surface? Sump is in the garage.
Will this turn my plenum into cement?
<Don't know about the latter... but you don't need, want this much feeder stock, this low a pH effluent... Experiment a while... perhaps on a non-living set-up. Bob Fenner>
Thanks,
Steve Heathcote

New Calcium Reactor
hi bob, or j (if your still filling in)
<<JasonC here...>>
my calc results after a week are ok i guess; calcium 420, but alk is way high (14+), and ph is quite low (7.9-7.95). the fish are fine; corals looks like they're adjusting (not opening up occasionally, etc).
actually; my leather hasn't opened up since i started using the reactor (due to low ph? it used to be 8.2). <<a possibility, yes.>> is this what I'm looking for in a steady state? do i just give the animals time? <<well, I would definitely be at work trying to get that pH back up.>> my concern is that my alk is already high, so ph probably wont rise much if at all further? should i be concerned with the low ph? <<yes>> my effluent is ph 6.86-6.91, AquaMedic using the included hydrocarbonate. your opinion is appreciated. thanks, <<would try the Baking Soda regimen to see if this will help the buffering in your tank. Something is definitely amiss.>>
Javier
<<Cheers, J -- >>