Please visit our Sponsors
FAQs on Calcium Reactors, Operation By Brands, Makes & Models

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

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

Pay attention to "management" issues in picking through designs... My big pet peeve is with some models that are real trouble to take their contact chambers apart... and put back together... I REALLY hate screws here! And feel the same re O-rings that are not in external races! RMF

Calcium Reactor Upgrade, sel.      12/15/08 Hello Media Crew, <Matthew> I have been fidgeting and fussing around with my Knop C for sometime now. Its for a 200 gal sps system. <Mmm, okay> Everyday it requires readjusting of the effluent dropper, keeps getting clogged/loses consistency intraday...very time consuming and unstable for corals & constantly having to test for KH & calcium. I am convinced my Knop reactor is failing to maintain STABLE Alk and cal. levels because the sps aren't growing as fast as they could be. I'm also concerned that my reactor size now isn't big enough for the grown-in/higher demand for calcium..bigger corals, lots of coralline etc... For these reasons, I am considering upgrading to a CR2 Dual reactor with capacity for 14 lbs rather than 3.3 lbs, and also for its ability to maintain CONSISTENT effluent drop rates, my most important concern... I think the original Knop C was a "first model breakthrough" reactor at that time 1991? and we have much better more reliable models & custom makes on the market today. At the time of purchase.. 1 year ago, I had never fully and completely understood how they worked and this was my first attempt with A reactor...makes sense I guess... Since then maybe I have discovered flaws and reactor necessities as well as the essential demand for cal. and Alk. stability for sps. <Mmm, well: http://www.aquadirect.com/store/product.php?productid=21026 appears to be a substantial unit... I don't like the tops/fill-empty closure mechanism... those white screws... a pain... And I would take a read around the BBs re this unit...> Reasons for upgrade: 1) Reactor chamber too small (3.3 lbs) <Is too small for your system/application> 2) Knop C effluent dropper very inconsistent/unreliable <Likely mostly # 1) above and who knows what used as substrate (not real Korallith?)... perhaps purity of CO2...> For these reasons I am Saliferting and making adjustments to cal. Alk. EVERY OTHER DAY!!!! AGGH!! <No fun for sure> Hopefully I can test each ONCE A WEEK, right?? and not have to make major adjustments because I will hopefully have STABLE values...? <Yes> You thoughts on the matter are appreciated. Thanks for your time, Matthew <Mmm, for the sum of money et al. what's involved, I'd instead go with the AquaC unit: http://www.proteinskimmer.com/Product%20Pages/RX-1.htm Bob Fenner>

Knop C Calcium Reactor, media, reading  10/24/08 Hello, Quick Question: How do you know when to replace the reactor media?, <Mmmm, depends...> its been ~ 4 mo.s since starting it up... Has been losing efficiency as far as operation, a huge bubble forms at the top of chamber <Ahh, this is most likely due to impurities in your CO2... do make sure and get pure... other gasses are not nearly as water soluble> and has a hard time with effluent constantly getting jammed up. <Now... the question... are you using Korallith? Or some off-brand, or?> The media has turned from its original whitish color to a more dull gray color. <?> Am I supposed to wait until the media completely dissolves? or replace when media becomes a dull gray color? <Mmm, no... though even the best media choices won't "melt down" entirely, none should turn gray... I would either "shake" the media in the contact chamber, replace when it's about half the height of original, or use your effluent pH as an indicator where you're not using a meter (when it dips, time to replace)... Do read on WWM: http://wetwebmedia.com/calcreacmedia.htm and the linked files above. Bob Fenner> Thanks for your time, Matt
Re: Knop C Calcium Reactor  10/25/08
Hey Bob, <Matt> Thanks for the reply. Apparently after Servicing my Knop c reactor for the first time ever after 3-4 months, I discovered that the inefficiency in the reactor and "bubble at the top" as well as the "gray media coloration" were because of major blockage within the chamber. <Ahh!> After taking out the media and rinsing it off.... much "gray" particulate water was witnessed and the media returned to its normal white/beige color. Over the course of 3-4 months...the C02 had dissolved the media rather well also leaving behind dissolved particles which started to block up in the reactor therefore causing the Eheim pump to not be able to effectively circulate water within the reactor... causing the bubble at the top... causing blocked effluent....etc..etc.. Final conclusion on this matter: Service Calc Reactors Quarter annually for effective results. <Sounds reasonable> and yes..media is Korallith, good stuff <Ah, agreed... the best> ...I also get top quality c02 from reputable supplier, but will be aware of avoiding poor quality c02 from any other future sources. <Good> I appreciate your advice/help. Thanks, Matthew <Welcome. BobF>

Calcium reactors (and more) 5/25/08 Hi.. <Hello!> I was considering Korallin C1502 and . It would be better if you know my current setup.  I have a 80 gallon reef aquarium with a 20 gallon sump on a Aquamedic OR1200 pump. I am using a Tunze 6060 and a MaxiJet 1200 for circulation. Protein skimmer - AquaC EV180. Lighting - 2x150w 14k Ushio Metal halides and 2x Aquamedic 10k 54w each and 4x Aquamedic actinic 54w each.  My current parameters are calcium - 350ppm, nitrate, nitrite, ammonia and phosphate - 0. My pH ranged this week from 7.9 to 8.8 (eeks).This happened as I used Kalkwasser without a ph controller. I was deciding between two reactors for my tank the Korallin C1502 and KNOP C. Firstly, is the KNOP C aqequate<adequate> for my tank if I stock it heavily with SPS corals? Secondly, which one is better? Thirdly, do you have any other recommendations? <Both reactors listed are small in size and the amount of media that can be used. These are both good units for your tank, but it has been my experience over the years that people usually upgrade as they become successful. For that reason I would recommend a GEO612 would be best. It holds more media, is easy to work on, comes with an Eheim pump, and is a very reliable unit. The GEO612 is also bigger than the KNOP HD at half the price.> I want to know what you think of my plan - get Kent marine liquid calcium to boost calcium to 440ppm and then use my calcium reactor to maintain that level. I understand that is how you are supposed to do it? Will this work? <YES. The calcium reactor can catch up on its own also.> Also I plan to buy a ph controller with my calcium reactor. How is Milwaukee SMS122? How does it compare to the pinpoint controllers from American marine? Why is there such a difference in price? <I prefer the Milwaukee units. Their customer service is bar none! They have very reliable units and their probes are also very reliable. It comes down to personal preference as both units will work, I am just a stronger supporter of Milwaukee products.> Thanks and I hope these aren't too many queries at one shot. <No problem. Also, if the GEO is out of your price range the KNOP unit is very well made.~Rich> msayani2.

Calcium Reactor Instructions, Korallin  12/25/07 I recently purchased a Korallin Calcium Reactor 1502 from a private seller on EBay. Unfortunately, no instructions were included. Can someone email me a copy or make me aware where I can find these? Michael A. Grande <Email, write or call Marine Depot (.com)... in Orange County, CA... the U.S. Distributor of their line. Bob Fenner>

Knop S-IV Air Bubbles Resolved! 5/2/07 Good morning all, <And to you, David.> Ok, so this isn't a question but an AH HA moment!  I posted my original questions here regarding gas block, and air being trapped in the reactor, and I received the right diagnosis that air was being introduced, but I didn't find the source until this weekend.  I'd chalked it up to an impure CO2 source after changing out the blue coarse filter pads and changing out the media, re-tapping all the fittings, and changing all the air lines and the CO2 tubing.  I even bought CO2 from another source, but nothing helped. Well, last week I move all my equipment and sump to the garage, and ended up plumbing the whole thing under my house which was no easy task, because it required 75 feet of both 2" plumbing for drainage and 1" for return, but that's another story.  Anyway, I ended up tapping my 1" return with a JG fitting to feed my reactor using 1/4 RO tubing, and changed the threaded fitting for the water input on the Ca reactor to a JG fitting as well.  After, 24 hours no more bubbles and it's now way more efficient!  I realized at that moment that the air was being slowly brought in from the siphon feed from the tank!  I never thought of that.. Doh! Anyway, I just wanted to share my experience just in case others are having the same issue.   You guys have helped me immensely in my success, I just wanted to give back in a small way. Thanks Wet Web Crew! <You're welcome, David, and thank you for sharing this information.  Will post for others to read.  James (Salty Dog)> -David    

Calcium Reactors, brand/sel.  4/16/07 I'm in the process of researching a calcium reactor for my 550 total volume reef tank.  This is my first calcium reactor since all my previous tanks were smaller and I never had any difficulty keeping my calcium and alkalinity up.  My setup will be a mixed reef (no surprise) with 80% softies/LPS and 20% SPS.  I have always trusted the opinions of the WWM crew so I figured I would ask a question and I did search your archives but I did not see any mention of the three calcium reactors I am looking at.  The three models are the Deltec PF601S, Schuran Jetstream 1, and the GEO 818.  What are your thoughts on these models and if you think of another model I should look at please let me know. <Mark, I'm not familiar with using these products.  I can say that Deltec has a good reputation.  You may also consider the Knop reactors which I believe work very well.  My suggestion to you would be to post this question on our chat forum under "Equipment And Dry Goods".  Here is where you will get opinions from people that are/have used these products.   Go here:   http://wetwebfotos.com/talk/> Thanks <You're welcome.  James (Salty Dog)> Mark Crist

Converting Fluidized Bed filter to Calcium Reactor Hello from Calgary to the Crew << Hello up there, Blundell here this afternoon. >> Your service to the hobby is incredible and you have improved my personal experience greatly.  Thanks in advance.  I have a 66 gal reef setup that is 2 months old that I inherited from a friend, it had been running for 6 months previously.  I have hence nursed most of it back to health.  A Rainbow fluidized bed filter came with it and it has been running the whole two months, from what I have seen on WWM the FBF is not necessary and potentially detrimental now that the live rock seems to be actively developing a health population of coralline algae and life in general.  If I were to replace the sand media in the FBF with media for a Calcium reactor and add the required CO2 system to the input of the FBF could the FBF be converted to a Calcium reactor. << I would search around on the internet for DIY calcium reactor plans.  Most people have used a pvc base to make them.  Your idea could work, but rather than converting the FBF over, it may be easier (and possibly cheaper) to just make one from scratch. That is what I would do. >> Hopefully I am making sense. Thanks Lonnie <<  Blundell  >>

- Knop Type-C Setup Question - I bought this reactor long times ago and was not able to use due to change of my reef to fresh water so I let my friend use it for 1 1/2 years and got it back 1 year ago and now I take it out from my storage and have a question. There is a blue tube inside of reactor is this connected to outline side or CO2 coming in side? <The CO2 coming-in side.> This is tube is loose from somewhere and could not figure out where to connect and do not have correct connector I think. <It should just press-fit into the fitting on the top of the unit.> Is there a special connector on this blue tube to Co2 or outline? <No.> Can you send me this special connector? <If you are missing the fitting on the top of the reactor, you can contact Diana at knopproducts.com and she'll be happy to provide you with any parts you might be missing.> Thanks Chris <Cheers, J -- >

- Calcium Reactor Set-up - Hi 5 days ago I hook up your Knop S IV, my reef tank is 350 gals and I have many live corals, I tried with 20 co2 bubbles and 2 drops per second and the ph value is 6.8 to 7 and when I rise to 120 bubbles per minute than I get the 6.1 value but the water at the top of the cylinder is very close to the outflow and the co2 will go in my tank ?? my questions for you is the S IV is big enough since you rated for up to 300 Gals. and is there a way to adjust it correctly, or since the guy at the aquarium center that sold me the unit I should ask him to replace it for the Knop HD-S. <Hmm... you might be better off with the HD-S. 300 gallons is indeed about the limit for the S-IV, but depending on your needs for calcium, could easily operate on 400 gallons. I run an S-IV on my 400 gallon system but I'm not keeping any corals or clams, I merely want to keep up with trace element supplements, including calcium. By running the S-IV at a reasonable rate, I manage to pull this off. If you are pushing beyond the limits, which 120 bubbles per minute would indicate, then yes, this reactor is undersized for your needs.> I would appreciate if you can give me a feed back very soon so I can clear the matter with the store here in Montreal CND, since the policy here is 10 days for exchange. thank you Sylvain Le Saux <Cheers, J -- >

- Knop Type-C Questions - hello I have bean reading thru your web site and I have learned a lot. well after reading about calcium reactors I found a good deal on a Knop model C I have read knops f a q  about the hook up I am using a tee off my main pump the problem I am having is the drip rate always slows down I have one valve to control the flow thru the reactor and that's off my tee. <Sounds like perhaps you obtained a used reactor without all the parts. Would be better off if you ran the output of your pump at full volume and then purchased a valve for the output side of the reactor... this is normally included with a new reactor.> also I notice that the water level is just above the pump is this normal I am using Knop media and when I adjust the water flow it seams like there's air in line all so can you tell me when do change the media or will it dissolve then add more one other thing is my ph is running at 8.0 in the day and 7.8 at night is this all right thanks for your help Paul <It seems to me that you may be putting too much CO2 into your reactor and you should perhaps try running your system with the CO2 turned off for a little while to make sure the pH in your tank is stable before you start running the reactor. Likewise, you should also pick up that effluent valve for the reactor as this will help you get the thing running correctly. Cheers, J -- > - Knop Type C Troubles - hello I ordered a new style bubble counter for a model c reactor  thanks got it Friday my problem is when I try to flow water the reactor from my pump its  pushing water in to the bubble counter I have put a valve on the inlet side with know valve on the out put side when I tried  running it with the valve on the out side the same thing happens so I put valve back on the input side can you give me any help thanks Paul <Sounds to me like your CO2 is not at sufficient pressure to stop water from flowing into the bubble counter. Your CO2 regulator should be set at about 10 PSI, which should be sufficient to prevent water from back-flowing into the bubble counter. Cheers, J -- >

- Knop S-IV Problems - I set up the s-iv and was wondering if there should be bubbles on the bubble counter inside the chamber? <Yes.> I'm using the Milwaukee ma957 and the bubble counter on the regulator set at 15bps but I don't see any bubbles on the reactor chamber... does it take a while for the co2 to travel into the chamber? <It shouldn't, no... is possible you have a defective or misplaced check-valve. Do make sure that the arrow on the black, Dennerle check valve is pointing towards the bubble counter inside the reactor. You may also want to check the outgoing pressure of your CO2... it typically needs to be set at 10 PSI to crack open the check valve.> thanks for your help.... <Cheers, J -- >

- Knop C Setup Diagram - Hello.  <Hello.>  Bought a new KNOP C Calcium reactor. The Installation "manual" that came with the system is ok - but is not specific enough for my tastes - a diagram would work well. Do you have access to or knowledge of an instruction sheet and or diagram that provides one with visual setup info?  <I've never seen one.>  One dilemma that I currently have is what to do with the airline tubing with the little shut off valve. Do I divide the tubing up for use between the water output and CO2 intake - I assume the little valve is to be used on the water output side.  <Yes and no. The silicone tubing is to be split between the water input and output sides. You should use CO2 proof tubing for the CO2 supply. And yes... the valve should be on the output side of the reactor.>  Any help here is appreciated. Best Regards, Stan <Cheers, J -- >

Aqua-Medic Reactor  10/4/05 Note: forwarded message attached. oh and one more thing, the instructions for this reactor are horrible, any chance of a kick in the right direction for output water and bubble count .. the aquarium is as follows 300L 2 Perc clowns, 1 blenny, one dotty back, and one pigmy angel, with half a dozen assorted soft corals.. all rather hardy might I add.. All I am after is some figures to look for and what and where I should set my controller to and in what location.. hope this makes sense, as I am in a great hurry and am about to get killed for being late :) <Garth, I suggest contacting AquaMedic direct at this link. http://www.aqua-medic.com/ James (Salty Dog)> Garth
Re: ph probe placement - calcium reactor  10/5/05
Heya guys, directly below I have attached my question and reply that I sent to AquaMedic and sorry about the confusion, but below that again, is my original question answered by James. I hardly think it is a no brainer. Possibly for the initiated, but there are not that many of them asking questions, as far as I am aware that is the whole point of this site, to learn.. Anywho... is there any chance you could please explain a little further as to why is it better to be controlling the ph in the tank (AquaMedic recommended testing the PH out of the reactor.. so now I am totally confused), I am assuming this will indirectly control the ph in the calcium reactor (hopefully at around 6.5?) I am just a little confused about the whole subject, and now I have received all my bits, I am a little hesitant to actually get it up and running w/o actually know what to expect and how to go about it. <Garth, just to square things up, the "no brainer" was not intended to intimidate you in any way. Lets try this.  Calcium reactors help automate calcium supplements to the tank.  They are generally used in larger systems/aquariums.  The components as you know are a calcium reactor, circulation pump, CO2 delivery system, calcium media and a ph controller.  CO2 is injected into the reactor chamber filled with the calcium media.  The CO2 creates an acidic reaction that slowly dissolves the media.  This dissolved calcium is then mixed with saltwater and the solution is slowly dripped into the main aquarium.  Now, in my mind, to effectively and accurately do this we need to monitor actual ph of the tank, so.....in my opinion and if I were doing it, I'd want the probe in the sump or tank.  Ph changes here will be relatively small as compared to placing a probe in a glass or whatever.  I really cannot comment on this anymore than what I have written above.  I hope this clarifies the problem you are having.  Good luck.  James (Salty Dog)> thanks, Garth REPLY FROM AQUAMEDIC: The latter would be the way to go. Your unit will not function very well with the probe in the tank. Cheers Mike > Hello > I have recently purchased your AquaMedic calcium reactor 400 and  AquaMedic regulator valve. > my tank is 250L - reef. I also have a c02 controller with solenoid valve, but I am unable to place the electrode inside the reactor, due to it being a > different size, fitting etc. would I be better off > putting the probe in the main display tank and have the controller set to 8.3.. or is it more advisable to have the reactor output flow into a small container with the probe in it and have the controller set to 6.3 or similar? > Thank you very much > Garth REPLY FROM WWMCrew Ph controller placement Hello again, thank you for the link, please see below regarding placement of ph probe, I have asked AquaMedic about setting up, but they will not comment on probe placement due to it not being their brand (sera).. any suggestions would be greatly appreciated as to have it measuring the effluent PH or reading the tank PH.. pros and cons, cause this has me stumped. <Garth, its actually a no brainer.  You would want to measure actual tank ph and control the reactor to give you the ph selected, so therefore, place it in the sump to constantly monitor tank ph. In future queries please do a spelling/grammar check before sending as it takes more of our time to correct these before being placed in the FAQ's. James (Salty Dog)> thanks in advance, Garth Heya guys.. first and foremost.. what a great site.. I owe a great deal of thanks to you guys and gals, info from aquarium shops in Australia is some what to be desired.. and very much 'made up' in most cases. Your info and advise is worth its weight in gold! Now on to the serious stuff... I have recently purchased an AquaMedic calcium reactor (the price was way to good to go past, even if it is not 'the best') AquaMedic regulator, and today I have ordered a sera PH controller (price.. it was half the price of all the other brands + the unit incorporates a solenoid valve within the controller).. now my question.. where should I place the ph probe itself? Should I make a small container and have the water out fill this up and then have it spill into the sump and have it testing the water in the small container (and obviously have it set to 6.5 or similar), or should I just plunk it in the sump and set it to 8.2 or similar.. also have you had any experience with these products mentioned.. reactor, reg.s, controller? Thanks very much for your quick replies as always.. Garth
Re: pH probe placement - calcium reactor  10/5/05
Thank you James, I too am glad we cleared it up, as there is a high possibility I may have take it incorrectly due to stressing out with the initial set up and what not.. Thanks again, and have a good day <Believe me, I know what stress is.  Garth, PLEASE, in the future do cap your "i's" and the first letter of a new sentence.  I really don't have time to keep correcting grammar.  Thank you.  James (Salty Dog)> Garth

Knop reactor 10/18/05 Hello crew, <Harold> I just wanted to ask your advice with setting my Knop C reactor on my 70 gallon reef. I measured the effluent and it reads a CA level of 230,  <? Too low> while a DKH or 21. pH is at 6.34. I have been tinkering with effluent drops and CO2 bubbles but can get the effluent to read a higher CA. I know a reactor is the way to go, but when I used Kalkwasser my C levels were always at around 370. I know I must be doing something wrong.   <Yes> After reading your FAQs, I have lowered drip to about 3 drops every two seconds and CO2 about 60 per minute. <This isn't the trouble> Any advice would be greatly appreciate it. Oh, I am using fresh Korallith as media. <... my first guess was that "it" was the media... What does your test kit read on your main tank? It may be a reaction that is mal-affected by the low pH... I'd take a sample of the effluent and shake it, leave it exposed to the air (to rid it of the excess CO2) and see if the calcium level doesn't "come up". Bob Fenner> 
Re: Knop reactor  10/19/05
Dear Bob, <Harold> Thank you very much for your response. <Welcome> I tried what you said and after 5 minutes the CA on the effluent measured 300, although to be honest  I don't know what I should now do with that information. <Mmm, understand that there is more free calcium than you had thought... that there may be more still> I had replaced the Korallith media about two weeks ago, so I don't know if the media could be the culprit, or maybe I should try CaribSea? <The Knop media is a superior product here> Do you have any ideas or suggestions as to what I can do to improve the operation of the reactor? Thanks, Harold Chamberlain <Yes... these are posted on WWM...: http://wetwebmedia.com/calcreactors.htm and the linked FAQs files above. Cheers, Bob Fenner>

Mainly sulfur/sulfuric-based calcium reactors   4/10/06 Hello Bob - I hope that you are well. <Yes Tim, thank you> I am sorry to be asking you a question, but hope that you will not mind! <Not at all> I am considering purchasing three 'miniature reactors' - http://www.reefworks.co.uk/default.asp?section=197 I would be using one with Rowaphos. <Look like nice, though small units> The second I wanted to use as a sulphur denitrator with the output going into the third reactor that I would fill will calcium reactor media or aragonite. The thought process was that the sulphuric acid from the sulphur denitrator would dissolve the calcium / aragonite thereby improving calcium levels in the aquarium, whilst at the same time avoiding the pH problems associated with a sulphur denitrator. <Have seen some makes, models as well as home-made units of these> I have no experience whatsoever in terms of using reactors and I was wondering what your view was on this - would it work? Would it be a good idea? Thanks Bob! <Can be made to work, though H2SO4 in the publics hands and fish tanks makes me very wary > I am currently revising for my university final exams so therefore the limited input - but I have been trying to answer at least the occasional email! Have a great day and again, thank you ever so much for your help! All the best, Tim <For the meanwhile, I encourage you to use a calcium reactor based on CO2 technology... much safer and still very effective... Bob Fenner>

Knop contact  - 03/14/2005 I was advised to ask you this question.  I have a Knop HD calcium reactor but I need to replace a broken piece.  Do you have any contact info for Knop to order this. Brad <Mmm, my wife, Diana used to distribute Knop... I will cc her here with your request... Otherwise, Marine Depot/Bayside is now their contact in the U.S. Bob Fenner>

Coralife Calcium Reactor - 04/14/06 Good Morning! <<About 11:30 pm now (East Coast Time)...Howdy!>> I have tried searching, but I did not any information on the Calcium Reactor I am looking into. <<Okay>> Does anybody know if the Coral Life <<Coralife>> Calcium reactors are a quality product. <<Mmm, haven't seen one of these "in the flesh", but would expect it to be as expected...a lower cost, lower quality alternative>> I know Protein Skimmer are many times overrated. <<Not sure I understand, or agree, with this statement>> Is this true with Calcium Reactors? <<As in skimmers, pretty much get what you pay for.>> I have a 140 gallon tank.  It only has a few fish - a fire fish, two blue eye Dispar Anthias, and a Pacific blue hippo tang.  They have all been in the tank for a few months.  The tank cycled with 6" DSB and over 100 lbs of live rock for almost a year. <<Excellent!>> I know that is probably a little excessive, but I am taking my time and trying to but quality components as the money allows. <<Not excessive at all...quite the opposite>> I am about to start adding some SPS coral but I thought it would be good to get a Calcium reactor installed and tuned first. <<Not a necessity...but not a bad idea either>> I have a 40 gallon sump/refugium with a AquaC EV180 protein skimmer. <<A quality product>> For lighting I have two 250W metal halide pendants.  As you can see I have invested a significant amount into the tank already. <<Is a function of the hobby me thinks <G> >> I do not mind spending more for a calcium reactor. The Coralife unit looks like it is less expensive then most. <<Indeed...to be fair, I don't have any practical experience with the Coralife unit...but for my money, I would look at a Knop or Precision Marine reactor, or maybe even Korallin>> If it works well and doesn't have any major drawbacks, I figure why not?  Any suggestions would be appreciated. <<Try posting your query on one of the message boards (Reefs.org/Reef Central) and see what folks who own one have to say about it>> Thank You Tracy <<Regards, EricR>>

Calcium use on WWM, Acetic Acid/Reactor use   4/26/06 Hi Bob, <Adam> Sorry it has taken me a while to get back to you. I have made a good start on the calcium topic. So far I have edited the main article, top XX faq's and about 10 of the FAQ pages. However, there are still several FAQ's I need to summarize and then I'll need to collate all the information and re-write the top XX faq and/or the main article. <Outstanding... I'm betting you've become quite well-versed on the topic by now> I'm sorry I have not been able to do this any faster. I have just bought a house (we move in this Friday) and work is hectic. I will finish the section as soon as possible. <No worries. All improvements are welcome> I feel that I have learned a lot by reading all the subject material about calcium. However, there is one question that I have not seen asked in any of the FAQ's that I have read. With regards to calcium reactors, is it possible to use vinegar instead of CO2 to dissolve the media? <Is possible to use... is the simplest organic acid, Acetic, CH3COOH... have seen commercial and home-made units utilizing this (and "stronger" and more concentrated inorganic acids... mainly in Europe> And, if not, why? Or...perhaps that should read, vinegar (acetic acid) is an acid that will breakdown the reactor media. Why is it not used? Acetic acid is cheap and readily available. It would be a much easier and cheaper solution compared to bottled CO2 if it was suitable. Cheers, Adam Langman <Likely the "answer" lies in the CO2/Carbonic acid being easier to administer, meter... less of a liability (as in lawsuits)... and the/a "founder effect"... folks staying on a so-called bandwagon of technology due to their being familiar with only it. Cheers, Bob Fenner>

Knop C Calcium Reactor Instructions - 10/26/06 Hello- <<Howdy>> I recently purchased a used Knop C calcium reactor from EBay for my 125 gallon reef aquarium and unfortunately the seller did not have the operation manual.  Try as I might, I cannot find a copy of the manual online and I am extremely frustrated as this is my first calcium reactor and I have almost no idea how to set it up. <<Contact Marine Depot re an instruction manual...they are a U.S. distributor for Knop products and should be able to help you out>> The unit appears to be in great condition and the seller provided all the CO2 tubing and the Eheim pump.  I have a 5lb CO2 bottle and am shopping for a suitable regulator and pH monitor (any suggestions?). <<Marine Depot offers a decent regulator w/solenoid, and either the Pinpoint or Milwaukee pH monitor will serve well>> Can you please provide any information about how to properly install this unit? <<Here's a brief explanation from Jason C. who has considerable experience with the Knop reactors: "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." >> Thank you for any assistance you can give!!!! <<Quite welcome>> -Dennis <<Regards, EricR>>

Calcium Reactor without CO2? - 12/14/06 Hello crew! <<Howdy!>> Long time reader, first time writer. <<Welcome>> My main question is, is it possible to operate a calcium reactor without CO2 injection? <<Strictly speaking, sure...but it would be of little use/benefit to your system if operated in this manner>> This occurred to me after measuring pH of my RO/DI water and it was 6.5. <<...?  Are you thinking of flowing pure RO/DI water through your calcium reactor?>> Does the carbon dioxide itself add alkalinity/provide a balanced calcium supplement or is the balance already present in the media that is used? <<The purpose of the CO2 is to lower the pH of the tank water/saltwater used to feed the reactor to a level low enough to dissolve/render in to solution the media in the reactor>> My thoughts were to dose some of my top-off water(6.5 pH) into a reactor via a peristaltic pump and back to tank. <<Mmm, I think I'm getting the picture now...maybe...  If you are planning to do this to condition/buffer the "top-off" water on its way to the display this would be fine>> Would this dissolve the media or is CO2 a necessary component? <<The low pH of the RO/DI water will dissolve "some" media...but not like that in a "conventional" reactor setup with CO2 present to "keep" the pH of the water depressed>> I currently use one teaspoon Tropic Marin Bio Calcium daily and dose Kalkwasser using a peristaltic pump for all top-off water and was hoping to add a balanced calcium method that does not carry with it the high pH of Kalkwasser or daily routine. <<The calcium reactor fed RO/DI water will take the place of the Kalkwasser for "top-off" only, yes?  I don't really think this will give you what you're seeking...but is worth the experimentation to see for yourself>> With Kalkwasser dosing (as much as 1 gallon in 24 hrs.), <<Is all relative...how big is your system?  I dose 4-5 gallons per day through a Kalkwasser reactor>> I often experience pH levels of 8.5, although no lower than 8.4, even at night; so very stable, but high(?). <<Some authors (Anthony Calfo for example) would call this "perfect">> The possible too high pH and daily routine are the only things that really concern me about my present methods. <<I don't consider you pH a problem...and the "daily routine" could be lessened by using the peristaltic pump to dose the Kalkwasser through a Kalk reactor>> I should say that the tank is a 50 gallon that inhabits SPS species and Tridacna clams and typically calcium is 380- 405ppm and alkalinity is 3.20-3.50 mEq/L. <<This is fine>> I am simply trying to eliminate part of the initial cost of a calcium reactor. <<Perhaps a Kalkwasser reactor is a better purchase for you then>> Thank you in advance for your reply. <<Quite welcome.  Eric Russell>>
Re: Calcium Reactor without CO2? - 12/15/06
Yes, was thinking I would continue adding perhaps 80% the amount of Kalkwasser top-off that I currently dose and dripping the remaining 20% or so calcium reactor effluent (made with RO/DI water) also. <<Honestly mate...this seems like more trouble for any benefit you think you might gain from this.  I would simply use the Kalkwasser reactor and calcium reactor (in the manner originally intended for this equipment) in conjunction with each other>> I have seen that it is common practice for one to do both Kalkwasser and calcium reactor nowadays, <<...is what I do>> however I'm guessing that a particular ratio of Kalkwasser/reactor effluent would be trial and error to achieve the desired results. <<Hmm...the Kalkwasser reactor would produce based on the evaporation rate of your system...the calcium reactor (fed water from the display and employing CO2) would be "tuned" for optimum performance.  Whether or not your system needs/could utilize both depends greatly on the size/stocking density of calcifying organisms>> I assumed that the reason one would do this, is to have the low pH reactor effluent and high pH Kalkwasser balance each other out. <<No...the reason for running both reactors would be to utilize the particular benefits of each and/or provide for heavy calcium demands beyond what either can accommodate alone.  In addition to the calcium/alkaline buffers provided by both systems...Kalkwasser provides for precipitation of phosphate/heavy metals, saponificaton to assist skimming, and pH support by tempering organic acids (due to its caustic nature)...a calcium reactor contributes essential earth elements (depending on quality of media) to include strontium, magnesium, some major and minor trace elements, etc. absent in calcium hydroxide (Kalkwasser).  Arguably on an "average" system, both methodologies can be replaced with frequent partial water changes>> I have also heard some freshwater tanks use calcium carbonate shells to increase hardness because they dissolve at the lower pH (?)/freshwater(?). <<Many Cichlid systems incorporate carbonaceous material to boost/bolster pH, yes>> This also made me wonder if CO2 may not be needed in a reactor to dissolve the media. <<For the reactor to function efficiently as designed it will require addition of CO2.  What you are proposing for buffering you top-off water could be just as easily; and likely more efficiently, done by adding the reactor media to the RO/DI storage container...in my opinion>> I hope I am being clear about my goal (?). <<I think I understand, yes>> I wasn't thinking of stopping Kalkwasser additions, just adding a bit of reactor effluent to knock down the pH a little bit and eliminate the daily routine of Bio-calcium additions. <<Mmm...better done by employing the calcium reactor in a "standard" configuration with tank water and CO2...IMO/E>> I trust your crew's advice, as I have lost all faith in the advice I get from my LFS. <<A shame>> I have often read the info on your site for hours on end. <<Me too! [grin]>> I had mentioned to one of them that I do a lot of reading to learn about this hobby and his recommendation was to stop reading and that most of the info out there is wrong. <<Ack!  Really?>> I strongly disagree with his ignorance! <<bravo>> Enough said.  Please let me know if you need more info and if I am sending my questions to you in the proper way. <<In the future, do leave the "entire" previous message intact (don't delete the replies) so we can see who responded to you>> I only learned how to e-mail about two weeks ago! <<The age (art?) of technology is upon us...>> Thank you! Gary Wallace <<Happy to assist.  Eric Russell>>

Is this normal? Knop Reactor...  1/5/07 Happy New Year WetWebCrew!  David here, and I need some help with figuring out if what I'm observing with my Knop S-IV Ca reactor is normal. When I adjust the drip rate it effects my CO2 bubble rate. <Mmm... a little maybe... there might be a pressure differential in the contact chamber that might allow this... but not much>   I siphon from the top of the tank to the reactor sitting on the floor, and it fills just fine so no impediments there.  I start the CO2, and I only have a few frags, and about 175 lbs of LR in a 150 gal tank, and my bubble rate is already 130/BPM for an effluent of 6.7-6.8 <pH> with a drip rate of 3 drops/sec.  This gives me roughly 8 DKH and 400 Ca and an overall PH of 8.0 - 8.15. <Sounds about right> But, if I adjust the drip rate lower it changes my CO2 rate lower.  My leather coral use to thrive when I was keeping my PH around 8.3 with Seachem additives, but has slowly shriveled up, and I'm assuming it is because of the lowered PH.  My effluent is 35-36 DKH, and my Ca is 500-520. <Mmm... too high all the way around> Maybe I have a bad solenoid or check valve? <No... just a bad adjustment...> I suspect there's some pressure in these units, but I didn't expect that it would do this.   <Mmm, there is a simple means of limiting the pressure to about right... using the stock tubing provided...> I've had the reactor for roughly 10 months, and this is the first time I've noticed it. <Umm... likely something else going on here... either the concentration/purity of your CO2 and/or the media you're trying to melt down... You're using Korallith I take it...> Also, can't maintain the same DKH and Ca values I once did with less CO2. <Mmm, see the above>   For example, I used to be able to keep the above values with 30 BPM, and a drip rate of 2 drop/3 sec's.  My bio load hasn't changed, so I'm wondering if the blue coarse filter pads at either end might cause a decline in efficiency over time if CO2 is only passing through parts of the blue pad even when properly rinsed? <Not these pads... they last forever... ostensibly... Don't need replacing... just rinsing with the periodic refreshing/re-newing of the media> I've tried different types of Korallith media, and tried 2 different CO2 bottles to find any particular source of inconsistency. <Oh! Good> Is there another type of media that is as good as Korallith media IYO? <Nope, not with this brand, type of reactors> My hope is (like everyone who has a Ca reactor) to be able to keep a PH of 8.2 to 8.3.  If I turn off my reactor at night, I would have an even harder time maintaining my current values, <Mmm, I would arrange a timer, not run the reactor during dark hours here> and I don't want to drip Kalk at night, because I tend to make mistakes with it. <You and most everyone else>   I don't have room for a refugium, and I can't use reverse lighting at this point. What can I use to boost my PH without working against what's already happening with a Ca reactor?   <Mmm, the simplest, safest way would/will be to add a commercial alkalinity booster... a part 2 of two part component product... something with sufficient carbonate... In/with your water change regimen. Bob Fenner> Thank you, -David Brown    

Knop Calcium Reactor Instructions - 02/06/07 I need to find out how to get instructions for a Knop s iv calcium reactor. Does anyone know how to contact Knop or have the instruction. <Try writing to: Knop Products, 8586 Menkar Rd., San Diego, CA  92126 <<Actually, contact Marine Depot (.com) re... the U.S. distributor. RMF>> or if you need some basic instruction, try a search here on WWM. this is a popular product, and there have been questions as to it's tuning and adjustment. -GrahamT> Thanks

- 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 -- >

Anemones 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 Anemone and a pair of clowns that have been in my tank for a few years now. The Anemone itself is about the size of a dinner plate. <Do you mean a Heteractis magnifica? There's no such thing as an Ocellaris Anemone, 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 Anemone and the clowns would get along with another Anemone of the same species but double the size and that has a pair of ocellaris clowns with it. Would the anemones get along together, and how about the clowns? If the two anemones touch is that a no, no? <I'd say maybe to the anemones, 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 anemones touching, I'd say no.> Are there circulation pumps on the market that are for sale that do not allow wandering anemones, 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.
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 -- >>

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 -- >

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>

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,

Become a Sponsor Features:
Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day New On WWM
Helpful Links Hobbyist Forum Calendars Admin Index Cover Images
Featured Sponsors: