- Equipment Issues -
Good Morning Wise Wet Ones,
<Good evening now... JasonC here.>
I hope you can help me with two problems I'm having with my tank. <Me too.> The 1st one involves my Knop C reactor.  With the unit setup properly, I can get the effluent Ph around 6.5, however, that's without the units circulating pump running, it can maintain it at this level for weeks. If I have the pump running, the reactor will run dry within several hours. <Something is really odd about that... I've used these reactors myself. The circulation pump should be running - I think perhaps you should turn the CO2 down, or perhaps better to ask, what is the drip rate of your effluent and bubble rate of your CO2? Effluent should be 2-3 drops per second. CO2 should be 1 drop every 4-5 seconds.> I have good flow supplying the unit, it's off the return line which is a Mag 12.  The valve flow rate is set to around 1.5 ltrs/hr.
My second problem is with my Aqua C skimmer.  My tank and sump is inhabited by a number of small, 1/4-3/8 inch snails, that love strong water flow. They tend to crawl up the intake of the skimmer pump and then are blown into the jets, thereby reducing the effectiveness of the skimmer.  I have to remove the jets at least once a week to clean out the snails.  If I put a sponge filter over the inlet to keep the snails out, will that decrease the skimmer output? <Only a little bit and surely not as much as having a snail in the nozzle of the skimmer.>  
Thanks so much for all your help over the years.
Andy
<Cheers, J -- >

- DIY Calcium Reactor Question -
<Greetings, JasonC here...>
I have made my magnum 350 into a calcium reactor by making a manifold out of pvc, to inject carbon dioxide, an outlet for effluent, and a dedicated pump for intake. Seems to be working well.  I have also put a passive reactor in the effluent line to rid the system of residual co2.  The system has been up and running for about a week.   I read your FAQ's, and it seems that people are getting really hard water out of their systems.  Does this take time? <Days...> My dKH is only 13. <A little on the low side, but not terrible to add to your tank.> The tank (full-blown reef) dKH is 7.  Calcium is 450 ppm, but so is the tank. <Ahh, the improved alkalinity will help, though.> I am dosing 25 bpm.  About 60 drips per minute. Effluent ph is 6.5 or so. <Be careful, you don't want the pH much lower than that.> Media is Korallith.  Do you think that the hardness will increase with time? <No... you need to look at how you might keep the water in the reactor a little longer. Most commercial reactors a recirculation devices, with the water in the reactor turned over several hundred times an hour. If your magnum is hooked up in the standard loop to your tank, you are likely not keeping the water in the reactor long enough to react with - hence the need for such a high rate of CO2.> I used to use Kalk exclusively, and am still dosing periodically, hoping the calcium reactor will catch up. <A couple of tweaks to the design and you will be fine.>  Any help is appreciated.  Thanks in advance.
Mike
<Cheers, J -- >

- Re: DIY Calcium Reactor Question -
The magnum is not in the standard loop like it normally would be.  I simply took the output, and put it into a pvc loop, right back into the input.  A dedicated pump feeds the manifold. I have co2 going into the manifold, and a cinch valve for the output, also in the manifold. So, I can keep the water in the magnum for as long as I like. <Ahh, ok... makes sense.> What should the "targets" be? <You mean for pH and alkalinity out of the reactor? 6.7-6.8 pH and alk. in the 15-17 range would be perfect.> LFS says that 450 ppm calcium is great, you sound like it's a bad thing? <No, no... just that your alkalinity in the tank was a little low, but the calcium reactor will fix that in time.> A little confused, here. <No worries.>
Thanks again
Mike
<Cheers, J -- >

Anenomes capability, Air pumps and Calcium Reactors
08/09/03
<Hi Stu, PF here with you>
G'day Guys,
A few dilemmas that I need clarification on if you wouldn't mind helping.
<Well, that's what we're here for.>
I have an ocellaris Anenome and a pair of clowns that have been in my tank for a few years now. The Anenome itself is about the size of a dinner plate.
<Do you mean a Heteractis magnifica? There's no such thing as an Ocellaris Anenome, at least that I've never heard of. Glad to hear it's living and thriving, it's a rare and happy thing to hear.>
I was wondering whether or not the Anenome and the clowns would get along with another Anenome of the same species but double the size and that has a pair of ocellaris clowns with it. Would the anenomes get along together, and how about the clowns? If the two anenomes touch is that a no, no?
<I'd say maybe to the anenomes, but you'd need a very big tank to do it. As for the clowns, no, they'd probably fight. Remember, they're in the same family as damsel fish and are territorial. As for the anenomes touching, I'd say no.>
Are there circulation pumps on the market that are for sale that do not allow wandering anenomes, sea slugs and nudibranchs from getting sucked up and therefore creating disasters within the tank?
<Well, you could hook a SCWD to the return pump from a sump (or do it as a closed loop). Tunze stream pumps are also supposed to be safer for such animals as well.>
Lastly I have purchased a Korallin calcium reactor c-1501 and the co2 and regulator to go with it. The instructions that go with for the calcium reactor are only 1 page long, and from these instructions they seem to assume you have previously had experience in the setting up process beforehand. Are there any photos you have of how the connections works or clear instructions for a guy that has no experience in this area before.
From my understanding the 4 outlets work like this. The Co2 outlet goes to the co2 bottle, the top air outlet is not connected and is just to let out any excess air in the chamber. The connection on the outside of the reactor with the valve I assume is the effluent to put water back into the sump, but needs to be above the water line to see the drops. Then  I assume the centre connection is for water to be collected from the tank and into the chamber,
I assume this is sucked up by the pump on the top from the sump, but this is when things went wrong, no water seems to be sucking up?
It says to somehow get the tank water into the chamber which I did to where I thought it looked full and also removing the air through the top outlet.
When I turned the pump on and the C02 gas, you could here the pump working but no water being sucked up, the C02 was bubbling and occasionally a few drops would be sent through the so call effluent connection. About 10 minutes the fish in the tank are gasping for air and it looked like co2 was getting into the tank?? Any ideas?
On the pictures it shows a blue attachment which I never recd, do you know what this is as it looks like a 2 inch tube connected by some tubing and clamped on the c02 outlet?
<Well Stu, in all honesty this would be a lot easier if I was there to eyeball it. I recommend that you contact the manufacturer and/or a member of a local aquarium club who has setup a calcium reactor before. Sorry I can't do more than that, but I would have to look at it to do more. Good luck, PF>
Thanks
Stu

Calcium reactor, pH Controller, Measuring dKH
Hi,
I have had a salt water tank for 25 years, and have been successful with water changes and additives.  My tank is  300 gallons and  just purchased the Knop Calcium Reactor.  Could you give me ANY additional set up advice?
<I'll do my best.> The information included with the unit was a bit sketchy.
I understand the plumbing of the system, but have questions:
1.  The instructions say to measure the reactor output - to be 12-20 degrees DKH.  Is that a simple alkalinity test? <Yes.> Is there a way to convert results from a conventional kit to degrees? <Well, unless the 'conventional kit' contains a specific alkalinity test, no. One the other hand, the units of measure vary from kit to kit, and there is a way to calculate to German degrees of hardness [dKH].> I currently use Aquarium Systems FasTest saltwater aquarium test kit. <Not familiar enough to say if this kit has an alkalinity test.>
2.  I purchased a CO2 Azoo unit and a marine pinpoint ph controller.  Is this necessary to monitor PH swings, for example, at night. <I don't think the monitors are 'necessary' but certainly good to have around.> I read on your website that they are not being recommended.  If this is true, how are the pH swings handled? <Depends on whether or not the pH is actually swinging. A drop in pH overnight might be best dealt with by shutting off the CO2 with the lights.>
3.  During a water changes, the main pump that feeds the reactor will be shut off.  Can I leave the circulating pump on the Knop running? <Yes.>
4.  Once the Knop is set up and running - do I need to continue additives, such as iron, trace elements, iodine, etc..
<Iodine, yes... many others are provided by the dissolving reactor media. Do look at the bucket your reactor media came in - should be a list of what you can expect. Not sure if iron is on that list. Do feel that most trace elements are best supplemented by regular water changes.>
Thank you for your assistance!
<Cheers, J -- >

- Broken Knop Part-
Hello Bob, How are you? <I can't speak for Bob, but I am well... JasonC here.> I'm writing you because I've exhausted my other leads and was hoping you may have the answer. <I think I may.> I have a Knop calcium reactor (the original type) and I've seemed to break the small blue plastic compression fitting that the bubble counter has screwed into it's top. The thing is useless as we all know and I'm eager to get it back up and running. Please let me know what you think about locating one. Thanks. <Yes, contact Diana Fenner at http://www.knopproducts.com/serv01.htm - she is the importer/distributor of Knop reactors and you can purchase spare part from her there.

Questions regarding the S-IV
>Hello-
>I'm fairly new to reef keeping, and I've never had a calcium reactor although I hope to change that soon. I have a 75 gal FOWLR aquarium. Once the reactor is set-up and calcium is good (I can only get it to hover at 300-350 now) I hope to add corals and a clam. 
>I've been looking into the S-IV model, but I have some questions regarding its specs.
>1) Do I need some sort of feed pump or tee-off to supply water to the reactor or does it siphon in?
<The S-IV model comes with an internal pump to move water through the reactor. Other KNOP models come with their own external pump>
>2) Is there an integral check valve leading to the bubble counter or does this need to be purchased and attached separately?
<The KNOP models come with check valves and bubble counters... very nice gear altogether.>
>3) What is the CO2 consumption on this unit like? Some reactors I've looked at mention bubbles rates up to 60/min while other models (aspirating venturi?) are down in the 10/min range.
<Mmm, somewhat depends on your desires, biomineralizing rate in your system... for instance, more stony corals, more light, more feeding... more CO2 can be applied. Most folks, applications utilize a bubble every 2-3 seconds...>
>4) How do I control the effluent flow rate?
<There is a valve supplied on the discharge end>
>5) Do I need some sort of quick disconnect coupling when hooking this up? (OK, I honestly don't know where I would need these, but I'm looking in the marinedepot.com catalog and they have them listed in the calcium reactor supply section.)
<Not necessary. There are other manufacturers of calcium reactors, and some of these have different arrangements for set-up/operation.>
>6) Is it a top-loading reactor?
<Yes... and thankfully one that is the very easiest to open, re-fill and close... A very important feature, advantage with KNOP>
>7) What sort of warranty comes with your products?
<One year>
>That's all the questions I can think of at the moment. I probably sound like a newbie, but then I guess I am. I just hope I didn't ask any stupid questions.
>Thank you,
>Karen
<Nope, all good questions, intelligently posited. BTW, there is more on calcium reactors and KNOP posted on WetWebMedia.com. You might take a look, starting here: http://www.wetwebmedia.com/calcreactors.htm
and read through the Related FAQs (linked, in blue, at top). 
Cheers, Bob Fenner>

- Calcium Reactor Issues -
I have a KNOP S-IV calcium reactor that I have had in service for nearly 6 months. I have problems with the unit taking on to much air at the top of the unit lowering the water line below the outflow and cavitating. My CO2 input is less than 15 bubbles per minute so I do not believe that this is a build up of co2. I recently installed a check valve on my co2 "in" line as I was getting water backed up in this line. <Seems odd... there is a check valve already installed in the reactor body - the black do-hickey threaded into the bubble counter.> Do I need to install a check valve on my water in line??? <I wouldn't.> Where my water line drips in to my aquarium, this line stops above the top of the water. Does this line need to extend down into the water??? <No.> Do I need to install a check valve on this line. <No.> The firm that installed my system has been of no help. Can you help me troubleshoot this?? <Hmm... would look to the inflow line to make sure it's not taking in any air with the water. Have seen this problem before with calcium reactors, and is the most common issue. CO2 dissolves very easily in water, air does not... start here, report back to me and we'll get this thing running correctly.> THANKS
<Cheers, J -- >

- Calcium Reactor Issues, Follow-up -
Thanks for getting back to me so quickly. <My pleasure.> The inflow line was connected to a water line feeding my ECO-WHEEL and I think that with agitation/other there may have been some air entering thru inflow line. Last night, I ran intake line directly to tank and I see no way that air could enter this line. Got everything up and running. This morning I checked and I have air in my reactor however, water is just above outflow and water still dripping in aquarium. Is this "air" supposed to be there?? <One should expect that a little CO2 will build up there, but not enough to stop the operation of the reactor. A last option to you is to try another CO2 source. Low-grade CO2 is not pure, and even small amounts of air in your CO2 supply will make the CO2 much less soluble in water and would show up as that air pocket at the top of the reactor.> Something worth checking.  My drip to aquarium is about one drop every 2-3 seconds. Is this OK?? <That's a little slow - I prefer two drops every three seconds with this reactor.> THANKS for your help!!!
<Cheers, J -- >

- Calcium Reactor Issues, More Follow-up -
As a follow up to my earlier e-mail, I went home at noon and the air level was below my outflow to the aquarium. I reduced my drips to the aquarium, could this be creating problems?? <Yes, I think you need to speed it up - commented as such in my previous reply - about two drips every three seconds.
Cheers, J -->

- Calcium Reactor Issues, More Follow-up -
What rate do you suggest for the CO2 bubbles to reactor?? I am trying to go for one bubble every 3-4 seconds. Is this o.k.?? <Yeah... that is fine, although testing the effluent will get you closer to what it needs to be - on average one bubble every four seconds or so is about right.
Cheers, J -- >

-  MTC Calcium Reactor and pH Controller -
OK I feel stupid asking this but I can't find a reliable answer anywhere. Oh by the way, GREETINGS !!!
I have an MTC calcium reactor hooked in to a Pinpoint (American Marine) pH controller. The instructions refer to the 2 plug-in outlets on the back of the controller as outlet 1 and 2. With 1 being the outlet that controls the CO2 addition (activates at low setting), and #2 should control the "flow" (shuts off at high). <Hmmm... would always leave the circulation pump on a calcium reactor running... unless of course the power is out.> The outlets themselves are not labeled, so I assume the one on the left is #1, the one on the right, #2. <Not sure myself.> I plugged in the solenoid gauge plug into the left, the calcium reactor pump in to #2. <Again... don't recommend putting the reactor pump on this controller.>
There are no diagrams on the instructions and no help on their website. Am I doing this right ?
<Couldn't tell you precisely... would contact the company that makes these directly.>
Secondly. I would think that I want constant flow from the reactor into the system, especially if the pH is too high, correct? <Ahh yes... we are on the same page.> Under this set up, if the pH goes above my settings, the CO2 still flows but the pump shuts off... Really lost here... Should I just plug the pump in separately? <I would.> Keep the solenoid in the left (as you are looking at the controller) outlet? <Again... be certain, call the company. Always feel strongly about such things as you paid them money - they owe you some help. Cheers, J -- >

- Hooking up a Knop HD-S -
Hello - I have purchased a while back an Knop HD-S Calcium Reactor and seem to have lost the instructions. I would like to install it. I spoke with Diana at KNOP and she suggested I write this e-mail. She did fax me a one page of instructions, but it has no diagrams and is still leaving me pretty much in the dark. <Ok.>
Do you have any additional more detailed instructions you could send me. <Not really... I can answer questions about it until we are both blue in the face however.> Also, could you please provide direction of whether or not you suggest a co2 solenoid valve controlled by a ph monitor. <I always suggest a solenoid valve, I don't suggest a pH monitor/controller unless you are a gadget hound.> And how about the second pump to drip into the sump. <Not necessary, but could be useful in your situation.>
Any help you could provide would be appreciated. <Please start by reading here: http://www.wetwebmedia.com/calcreactors.htm  - then feel free to write back and ask any questions that come to mind.> My tank is 2500 gallons, has a fair amount nice corals and I'm just getting tired of supplementing the calcium and alkalinity. <I bet.>
Thank You
Bill G.
<Cheers, J -- >

- Adjusting a Knop S-IV -
Good afternoon.
Firstly, thanks for a great site and helping us 1st timers to this hobby.
I have just purchased and installed a Knop S-IV reactor and medium grain Korallith on my 90G tank. <Good choice, is what I run.> I decided to use this product after reading good articles on WetWebMedia. If I may, my water parameters are as follow:
Before reactor
pH - 8.4 (day), 8.3 (night)
dKH - 11.5
calcium - 350
After reactor (past 2 days)
pH - 8.4 (day), 8.3 (night)
dKH - 11.4
calcium - 340
Effluent (current)
pH - 7.1
dKH - 17.5
calcium - 450
effluent drip - 650ml - 750ml per hour
CO2 - 18-19 bpm
When I first setup the reactor on Saturday, my effluent drip rate was 1ltr per hour (measured with soda bottle) and CO2 15-16 bpm. I left this running for 24 hours but the effluent pH never reached lower than 7.4 - 7.5 after the CO2 filter. The dKH was at 11.5 which was the same as my tank water. This led me to believe (maybe incorrectly) that the pH was not low enough inside the reactor to dissolve the media. <Correct.>
I decreased the effluent flow, now about 650ml - 750ml per hour, and increased the CO2 to about 18-19 bpm. The effluent pH dropped to 7.1 after CO2 filter as a result of this change (the current reading).
My questions are:
1) What should the effluent pH be after crossing the CO2 filter? <Roughly 6.7 is ideal.>
2) Should I run with the 18-19 bps CO2? <Probably not... this seems a little high unless you meant BPM.>
3) Should I increase the effluent drip rate back to 1ltr per hour and also increase the CO2? <No, better to adjust one or the other and then wait a day or so to test, then make more adjustments as needed.>
According to the manual the pH inside the reactor should be 6.0 - 6.2, my readings are 6.7 - 6.8. Too get the pH that low would require much more CO2 if I understand things correctly. <Or a slower effluent drip rate.> I did not think increasing the CO2 to achieve the stated pH above would be a great idea without checking first. <I'd start by reducing the drip rate.>
I would like to fine tune my unit by measuring effluent dKH and pH and would appreciate your response. <No worries, you're on the right track.>
Thanks in advance.
Fazil
<Cheers, J -- >

- Knop S-IV Reactor Problem -
I bought a Knop s-iv reactor & set it up about a month ago but it seems that I keep building up excess air on the top of the chamber. I want to know if this is normal or its a problem with the reactor. <Let's read on...> How can I correct this problem so it doesn't happen again. My drip rate is about 2 drops every 3 seconds. BPMs are about 40. <That's too much CO2... is the source of your problem. Should be in the neighborhood of 12 BPM. Try adjusting this and see if things improve.> Please respond to this e-mail to let me know what to do. I really would appreciate it.
Thanks,
Vinny

- Knop Type-C Questions -
Diana (Diana Fenner, Knop distributor N. America) said to give you a buzz about some tech questions I have so here goes.
All questions are for a Knop-c reactor
1-Diana's website lists silicon tubing as a replacement part.  Is this the tubing that I should use for the tank water supply to the reactor and tank calcium discharge lines to the tank? <Yes.> So the blue tube is only used from the bubble counter to the reactor interior? <That is correct.>
2-Is there a recommended lubricant I can use when servicing the reactor? After a time, the saltwater really makes all connections tight and I am worried that I may damage the reactor plastic connections during service periods.  I was considering Vaseline but I have read that it actually dries out o-rings and I am sure it is no good for the tank! <Yes, use silicone lubricant on the o-rings. Do not use spray silicone, but obtain silicone grease... available at your local scuba shop. Other than that, just don't over-tighten the fittings and you should be all set.>
Thank you
-Ray
<Cheers, J -- >

Knop C
>I would like to know if Knop c calcium reactor can run in sump. Is the discharge side of the main pump tee provided with the reactor? Thanks.
Greetings,
To answer your questions, yes the Type C reactor can be run in a sump, although it would take up perhaps more space than is practical. Enough tubing is included to allow you to install the reactor elsewhere.
As for the pump T-fitting, no, there is not one included with the reactor.
I hope this helps - feel free to contact us if you have any further concerns.
Cheers,
J --

- Setting up a Type-C Calcium Reactor -
I am currently hooking up my C reactor.  I have a 180 gal. main tank with a 55 gal. I use as a refugium.  The sump is probably in the neighborhood of 20 gal.  Since the reactor is rated for a 200 gal. capacity tank on the high end; do I need a faster flow rate than normal or higher bubble count? <Hmm... best to start off in the recommended range from these and then slowly turn them up - increasing the CO2 too much will cause a large bubble of CO2 to form at the top of the reactor and prevent the outflow from the reactor from working. You will need to find the middle ground by adjusting and testing.> Also, should there be some valve at the end of the outflow line to control the flow to the tank? <Yes.>
I read the flow should be in the neighborhood of liter per hour.  If so, I don't have that piece. <Can be obtained directly from Knop.> I got my Knop about three or four years ago and am just connecting it to the tank.  I have read more and more and am persuaded to get where I want to be with a reef system; the key will be alkalinity stability and a steady calcium level. <Indeed.> I read in one place on your page where the reactor should be filled with substrate and in another place that it should be 3/4 filled.  Which is correct? <On the Type-C, you want to fill the unit to just below the Knop label on the reactor.>
Your earliest response would be greatly appreciated as I am anxious (after having the unit for years) to get going.
Manfred
<Cheers, J -- >

Re: Knop-C Technical Support Request Knop-C Technical Support Request You both may remember me.  I recently purchased (partially given) a Knop-C reactor that was down for one month while the owner switched to a higher capacity Knop reactor.  I have done extensive research on calcium reactor before I centered on Knop.  I read all the good and all the bad.  I waited two years before I found a reactor that was in excellent shape and only had a single owner. After receipt of the Knop-C, I worked with both of you to get instructions, and to replace any part that I even thought were too dirty, or unusable.  I purchased a new filter for the unit and completely dissembled & cleaned it and replaced any blue tubes that I thought even looked damaged.  I replaced the Eheim pump just because that is how particular about my reef (which I now must return to dosing).  Both Ralf and Diana were spectacular.  In my research I also went to Di’s husbands website and read all the calcium reactor FAQ’s and information found there.  I went to the Knop website and read and printed the FAQ about calcium reactors I found there. However, I am now frustrated beyond belief!! The reactor always, always runs dry! Now before you both think I am a whiner or a simpleton, after me extensive research, and after my thorough cleaning and replacement of any Knop parts with factory Knop parts I tried the following. Upon start up, I noticed a blue tube that supplies CO2 in the center of the reactor, extending about ½ way down the cylinder, and cut at an angle.  I did not replace that tube. FYI, and in case I screwed something up, here is what I replaced: media round blue filter at the bottom of the media chamber, I replace the supply and discharge lines with the silicon (4/6mm) ones supplied by Diana, I replaced the pump supply and discharge tube couplers.  I replaced the CO2 supple line with silicon tube (4/6mm).  I found an American equivalent for the pump discharge tube coupler, but the pump supply tube coupler is a little large (not metric) and Ralf is sending me the tubes (but I could not wait).  The pump supply tube is clamped with four hose clamps to keep it secure and it does not leak water when the pump is off or when the pump is on (left idle overnight).  I also replaces all the media with the correct size as supplied by Diana. (I think 1.8mm it said but I still have one unopened container is you need more information.  I replaced the two o-rings with American equivalent as advised and the unit seals well and there is no leaks.  CO2 check valve is present and yes, I cannot blow through it at all ( a test I read to see if the check valve is working).  I replaced the pump for no reason other than I wanted a new pump with a spare.  It fit on and runs fine. To start the reactor, I did the following: 1-       filled reactor chamber with Knop reactor media (leaving approximately 2” at the top as advised by factory).  I did not measure the 2” precisely just FYI. 2-       Filled reactor chamber with Reverse osmosis water to overflow. 3-       Secured the 2 unions and sealed the reactor. 4-       Bled the reactor with the effluent line using the grey/orange Knop discharge valve as kindle supplied by Diana until no more air discharge from line. 5-       Started CO2 to 18-20 bubbles per minute.  I have two bubble counters, one on the gauges and one Knop version on the reactor.  The counts I am referring to are at the Knop bubble counter. In the morning, the chamber below the media was dry and the pump was running dry.  I read a small FAQ on the Knop website that stated to a person running 60 bubbles per minute that his reactor ran dry as the bubble count was too high.  SO I reduced it to 16-18, 12-14, 10-12.  I now am finally down to 8-12 at the bubble counter on the gauge which is about 3-5 bubbles per minute at the Knop counter.  The unit runs dry in about 6-8 hours.  All FAQs tell me to run the unit with the effluent valve closed for 24 hours while the reactor media clears.  The reactor fluid is clear now. I then tried a dry run by running the Knop-C at one liter per hours to see if that was the problem. no change. reactor still ran dry.  I read a FAQ on Diana’s husband’s website that said the CO2 may not be dissolving.  So I checked my source, a welding supply that has been in business since 1950.  I was told the CO2 is food grade, and that there is a hospital grade of CO2, but they don’t carry it.  No where have I read that I need hospital grade CO2. I am ready to throw the thing through the window. Please help…I have tried every thing!  I have re-filled/re-bled the reactor so many times I had to add new water to the 100g tank.  I re-fill/re-bleed the tank through the effluent valve and the siphon tube so I know the siphon tube is doing it’s job! There must be something I am missing, but I bought the Knop for it’s simplicity…so I cant imaging what I am doing.  Attached is a pic if that will help. Any and all suggestions will be tried and are appreciated! -Ray Ray, JasonC here from the WetWebMedia crew. After reading your email, I have a couple of suggestions. For starters, when you first fill the reactor, you want to let it circulate for a day or two with no CO2 addition and the effluent valve shut. This will allow the dust to settle. Any CO2 added during this run-in period will most certainly accumulate and put you behind the eight-ball when you finally do open the effluent valve. Also, when filling the reactor for the first time, you should be using saltwater - ideally water from your tank. On that note, the reactor should be supplied with water directly from the tank either by siphon, a T-fitting from the return pump, or a dedicated powerhead. Do not use the reactor for freshwater top-off as CO2 will most certainly accumulate in the times between when the reactor is actually toping off your tank. Also, I saw no mention of the drip rate coming out of the reactor. It sounds to me like you're not letting enough water out of the reactor. Shoot for something in the range of about three drops every two seconds. I've run the Type-C reactor before and this drip rate combined with about one bubble every 15 seconds seems to work very well for this setup. If CO2 still accumulates at these numbers try increasing the effluent drip rate. Lastly, the source of the CO2 is a rare cause of troubles. Nine times out of ten, the run-dry problem you describe can be remedied entirely by adjusting the input rate of the CO2 and the output rate of the effluent. My CO2 setup is quite similar to yours and I always use the bubble counter on the CO2 regulator as the guide to the rate CO2 is being fed to the reactor. Please feel free to contact me directly if you continue to have troubles. I'm confident we can get this reactor working for you. 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 -- >>

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 -- >>

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 -- >>

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>

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 --

- 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 -- >

[SDMAS] Calcium Reactor Workshop Signup (Southern California)<Old>
<Thanks much John. Will post on WWM. Hope to see you soon. Bob Fenner>
CALCIUM REACTOR WORKSHOP
Now is the time!! Please sign up for the workshop if you plan on building a reactor!
On July 20 at John Foster's house in the Hollywood Hills, MASLAC and SCMAS will host a calcium reactor building workshop followed by a BBQ. You do not need to build a reactor to attend. You can feel free to be an observer or just come for the BBQ! One word of caution: If you do plan on building a reactor someday, DO IT NOW. We are getting great prices, there will be many people there to help those that want it, and we will have all the pieces cut and purchased for you. To do this on your own "someday" will likely be harder and cost more!! If you can't make the workshop but would like to make a reactor, sign up and pay so I can buy your parts and we will work out assembly at another time. I will only be buying the parts once.
The Complete reactor (everything except CO2 tank and reg) will cost $110 (there maybe a slight refund if parts come in cheaper) (clear water filter cylinder $22, Mag 3 pump $40, misc. plumbing and supplies $48)
Plus for those who need it:
A special deal on the CO2 tank, regulator, solenoid and needle valve $154 (5lb tank $69, Regulator Combo $85)
If you get both you have a complete setup ready to turn on when you get home!! Operating instructions will be included.
To sign up:
1. E-mail me now drjohnf@att.net stating what you are buying, or that you will be an observer only.
2. By June 28th send me a check for the amount of your purchase. Send to:
John Foster
2801 Pelham Place
Los Angeles, CA 90068
Attn: Calcium Reactor
Thanks, a map to my house is attached and a schematic of the completed reactor is attached.
If you are using mapquest, it will show you the correct location but give you a terrible route from Beachwood Drive. Use my map from Beachwood to my house.
John Foster

Reactors.
I am a hobbyist in the UK and found your site to be a very good source of reference. Could you please answer these queries for me:
<I will try>
1) I am considering a calcium reactor. My stockist sells Aquamedic range, both open and closed units. He suggests the closed unit is difficult to regulate, is this true? Are there any other considerations?
<These (German) products are very worthy of your consideration... I do like the open units much more as well... they are much easier to adjust>
2) I already own an ozone reactor setup but haven't used it for some time. Is ozone use recommended anymore? Everyone's quick to remind me how it burns up all my trace elements amongst other things. What is your view on ozone in a reef setup?
<Yes. Am a big fan of ozone... very useful as an adjunct to otherwise well-filtered and maintained systems... Don't "burn up" minerals, very much in the way of vitamins...>
3) I could use the ozone reactor as a simple oxygen reactor, but does anyone bother with that these days? Does keeping the water at super-saturation give problems with low CO2 levels i.e. will my algae, anemone & corals suffer?
<No problems of practical consequence... though it is better to locate the ozone dumping into a protein skimmer, then into a sump, otherwise distal from the Carbonic acid discharge of your calcium reactor>
4) And finally, with a calcium reactor I guess it is high rather than low CO2 levels that are a potential problem. Would it be beneficial to run both calcium and oxygen reactor together?
<Not together as I state, but in/for the same system... just at "opposite ends" on their discharges>
Many thanks for your help.
Dave.
<You're welcome my friend. Cheers. Bob Fenner>

Yeast Calcium Reactor
Hi Bob,
I was still dreaming about my future calcium reactor when I stumbled across the idea of yeast as a C02 source. Do you have any experience with this kind of calcium reactor setup? 
<Yes... actually a great deal...>
I checked on a couple of the DIY sites, and it seems simple enough. However, some of the sites also posted horror stories of the yeast bottles exploding and turning homes into breweries!
<Explosions are exceedingly rare... easy though to make, transfer alcohols>
What do you think? If this is relatively safe and effective, I figure I could put together a DIY reactor for less than $150. Thanks in advance for the advice.
<Worth experimenting with, but really, a bottled carbon dioxide system is what almost everyone wants, needs... much easier to control, use. Bob Fenner>
Khoi

(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

Review (paperwork Americanization for new Knop Lime/Calcium Reactor)
Robert,
Thanks a lot for reviewing and Americanizing :-)
<A pleasure and honor my friend. Very glad to help make your line more accessible, usable to the market here>
NOTE: I would list the O-ring And the Gray/Grey Cover, Blue Tubing… as Replacement parts and as part Of the unit. They are mentioned In the Installation instructions.
Thanks, makes sense
<Yes>
NOTE2: The instructions call for fittings to remove and return water to/from the aquarium (or sump more often in the U.S.). Are these included? “U”’s, intake strainer… Is there a “Parts List” included with each Kalkreactor? And a list of what’s not included? (e.g. Outflow Valve…)
The unit comes complete for operation including all the material mentioned, except Korallith filling. But its a good idea to include a list of the contents, so the customer can assure that he is complete.
Maybe we should even make a simple diagram of all parts to show how it will be assembled.
<Ah, good to here it is complete as a unit (sans the feeder stock)... many Americans don't have ready access to fittings. A "Parts List" is a useful guide to laying out all components before assembly. Looking forward to the new calcium reactor's release, distribution here. Danke shoen, Bob Fenner>
Best regards,
Daniel