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FAQs on Calcium Reactors 1

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

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

A very nice DIY calcium reactor at Mark Trimble's house

Hi Bob, 

I've been trying to keep my levels as stable as possible using only water changes and adding liquid magnesium (as this seems to be the main parameter I struggle to keep up) I'm using D-D H20 salt and do 15% water changes of around 50 litres per week. But, I'm still finding that most weeks my kH drops by 1 (it's usually 9 after a water changes then 8 by the end of the week but sometimes drops slightly below 8) I'm reluctant to use buffers, as I know that it isn't sustainable as it could lead to my kH rising gradually.

I've been exploring balling lite but I'm still a bit perplexed by how to dose and I was never really very good at chemistry!
Would a calcium reactor help keep everything even or will it just maintain just calcium? I do add coral grower and trace elements weekly but am I doing enough to keep everything stable?

Thanks in advance
Katie Advani  

Salve Katie. Might I ask how you are adding to your Mg? Simple Epsom Salt (Magnesium Sulfate, MgSO4) addition is my fave'¦ for being inexpensive, effective and readily available. Next, the loss of KH, dKH can be due to a few circumstances'¦ most often due to livestock metabolism, uptake by biomineralizing life. In essence, overall processes in captive systems are reductive, acidic, with loss of alkalinity a common affair. And corals, calcareous algae and more can really use up a good deal of alkaline reserve (along with Calcium, Magnesium'¦), particularly in brightly lit, over-driven settings. You don't mention your livestock and/or feeding practices, but these may be an important part of the puzzle here, as might be inefficient skimming.            

            I'm a bit confused re your reluctance to utilize a commercial buffer. I definitely would read up, employ one myself'¦ Best dissolved into new/make up water for when you do your weekly maintenance. I want to help you set aside your worries here re simple chemistry. You mention the use of a 'coral grower' and some supplements; I encourage you to spend some time with your in-print works and the internet reviewing the listed active ingredients, their interactions. Again, I would be using an 'all in one' (carbonate, bicarbonate'¦) buffer if this were my system. 

            Concerning the question of use of a calcium reactor, depending on the media you're using, melting down, mostly Calcium and Carbonate will be provided. There are some products that will also generate free Magnesium. IF you have a large system (hundreds of gallons) and/or a good deal of valuable biomineralizing life (e.g. stony corals) a calcium reactor might be worth considering. However, I'd gain a basic understanding, working of the system without one first.

You know... if you need anyone to test and review that new Knop calcium reactor I just might know someone who would want to try it ;-) <Ah, will pass this on (to the boss who you'll meet, dive with in May). Bob Fenner> Cheers, J --

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

JPG Calcium Reactor new (New model reactor coming from Knop) << 1131-Cjpg.jpg >> <Very nice. Hope to see this in the U.S.A. soon. Bob Fenner>

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

(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

Calcium reactors Bob, Have been reading your page for a while and has helped me some. My questions is how to you control your ph when a calcium reactor is running?  <There are a few ways... we measure the output for pH, biomineral, alkalinity at first when setting up these units, then actually don't control the pH at all (the systems we have/had are quite large (a few hundred gallons), raising corals... pulsed only during daylight/photosynthetic heights...) I have a ph controller but don't really know what solution would be best for raising ph. <For raising...> I am assuming Kalkwasser but I wanted your feedback. <Oh... most folks set the effluent pH to something about 6.7, 6.8... with a "stock" feeder material... either "raw" (like coral sand, crushed coral/substrate...) or produced (e.g. Korallith) and rely on their controller to deliver about the right material per the ratio of carbon dioxide to melted feeder material over the duration of the use/replenishment period... Kalkwasser (calcium hydroxide) is unnecessary, possible trouble used in conjunction. Please read here: http://www.wetwebmedia.com/careacfaqs.htm Bob Fenner> Thank you - Adam Jackson

Calcium reactors << Jason C here, giving Bob a day off, so to speak. >> Bob, Have been reading your page for a while and has helped me some. My questions is how to you control your ph when a calcium reactor is running? I have a ph controller but don't really know what solution would be best for raising ph. I am assuming Kalkwasser but I wanted your feedback. Thank you - Adam Jackson << depending on the brand of pH controller, you may have the ability to turn things on and off, depending on the pH you choose. You would use this feature to slowly meter-in the effluent from the CA Reactor, then at an appropriate pH, turn off the circulation pump so that the effluent stops its flow into the tank. If your pH device is just a monitor, then perhaps it would be safest to run the CA Reactor over night, when the tank pH is naturally low already. As far as Kalkwasser goes, a CA Reactor is a high-tech source of Kalkwasser, so there is no need for you to dose it in addition to the CA Reactor. I hope that is helpful - J-- >>

Calcium reactor Dear Bob: I have a couple of quick questions I hope you can answer in your unbiased manner. 1: Are Calcium reactors as efficient as the seem in print? <Some are about all they seem to state... there is an enormous range of "cut and glue" versus scientifically engineered, well-constructed types... AND very importantly, the actual use/maintenance is an extremely large factor in actual function of many/most units... That is, if not "kept up" with replacing/shaking media, bubble count/effluent pH... the best, better reactors are no better than the worst.> Does the CO2, in addition to making the reactor carry out its primary function have any other benefits for the tank? <Many... most importantly to provide overall homeostasis chemically/physically, drive the light reaction of photosynthesis...> I dose my tank daily now and was looking an improvement. However, the cost of the average setup warrants some further research. <agreed> Any suggestion on a brand if you do advocate its use? <Knop... a paragon of excellence... Where to start here? I advocated (in person, en voce in the hobby press...) the use of foam fractionators for thirty some years (very lonely years back...), and calcium reactors for going on twenty... seeing them in use in aquaculture, in the "big" trade shows, principally the Interzoo every other year in Germany... And not the relatively toxic, expensive use of Kalkwasser... Look at the features on the seemingly simple Knop products: great pumps, solid components, direct, easy to reach controls. Their link: http://www.knop-usa.com/ Note I state, "look at their features"... an aquarist can build their own, and there are many other new models/makes by others... all worth considering> 2: I have a basic sump filter that I have placed some live rock in, I don't have any light source in or on it being that it's located under my tank stand, and of a material light won't penetrate. I was wonder if the rock can do its job and what would be the improvement if I do manufacture a new top and light it up. <Mmm, there are advantages even to unlit sumps of this sort... Or if so inclined, even "underwater" light fixtures available... I would modify the top, place a light, run it either reverse photoperiod with the main system (with a few hours overlap), or continuously> I also gather from your readings, that some tanks with refugiums in place have no mechanical filters in place. What polishes the water?  <The life in, on the rock, substrate, other surfaces> Do these types of systems work with fish in the reef tanks? <Yes> 3: How would a small sand bed do if I place it in the sump. By small, I was thinking of a 7"X9" Tupperware type container, 2" deep with live substrate placed within. I would then cover it screen of some sort to keep it contained. If that's the wrong approach, how could I improve it? <Some folks use deep sand beds, plenums, substrates in their sump/refugiums... some only live rock... depends on your esthetic desires, what you're hoping to achieve with such use... if you have a calcium reactor going you won't likely need/benefit from more biomineral, alkalinity... but if your livestock eat the sorts of organisms cultured in such material... Read through the Refugium FAQs here: http://www.wetwebmedia.com/refugium1.htm DSBs here: http://www.wetwebmedia.com/dsbfaqs.htm> 4: Final point. Why doesn't all the rock and sand in my display tank do the job of filtering and nitrate breakdown? <Can... given very little livestock, restricted feeding... but more stable, optimized to have more volume, more rock/sand... and alternating light/permanent cycle in an added sump where a lack of predators allows for other life production. It's full of the same life I see on the rock in the sump. <Ah! You have a good mind, discerning. Look into the Intel QX3 microscope: http://www.intelplay.com/products/qx3/ and consider what sorts of sampling, recording, enumeration you might do to test, see the "preponderance", abundance of life in both settings over time...> Thank you for your valuable time. You provide a fantastic service. Brett Manthe <You are welcome my friend. Thank you for asking, sharing. 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

Ca reactor Any recommendations on a small (possibly a hang-on-back) calcium reactor for a 45 gal reef. If not available commercially can one be made by a somewhat handy type of guy?  <Yes to the latter. Please peruse "Oz's Reef", site of choice for pet-fish DIYelfers: http://www.ozreef.org/> Cost is a big factor as I face immanent divorce if I keep spending money on this wonderful hobby. <More than worth the monetary cost for what such activity will save you in your sense of self-worth, involvement in the real world.> Much thanks in anticipation of your reply. Raul <I am with you my friend. Bob Fenner>
Re: Ca reactor
Thank you for you reply. I agree that this hobby does a lot for my overall personal well being. <Mine, definitely> I am a computer network guy by trade and many times contemplate how much happier I would be if I could work in the reef hobby for an occupation.  <Perhaps you could do a few installs, help folks service same... An easy job (and very enjoyable... I did this for nineteen years), with generally flexible hours, decent pay... As a side job.> Planning and maintaining my reef bring me much joy and even more important is the quiet calming effect which it has on me. It seems to make our hectic lives more complete. Thanks again for your comments and I will definitely check out OzReef. <You won't be disappointed my friend. Service to you. Bob Fenner>

Calcium Reactor questions Hello Bob! Thanks for you WetWebMedia site; the information has been invaluable and I have recommended it to everyone I know who is planning or currently has an aquarium (sorry if it results in too much e-mail!) <Ah, thank you, no problem> Anyway, I have just installed a Korallin Kalkreactor on my 100 gallon tank and the media I am using is Super Calc Gold. The reactor has been running for approximately 1 week. The CO2 rate is 25 bubbles/minute, at a drip rate of 60/minute. The effluent properties are pH = 6.6 to 6.8, Ca = 440 ppm, Alkalinity = 13 meq/l. The tank water properties are temperature 80 to 82 F, pH of 8.2, alkalinity = 3.4 meq/l, but the Ca is only at 250 ppm. This is actually an improvement, as before the reactor, I was constantly fighting with additives to get the calcium above 230 ppm. <No worries... Give this program, gear time> The tank is approximately 4 months old. The invertebrate animals that I have in the tanks are three hard coral (Mycedium, Euphyllia, and Caulastrea), several soft corals (Sarcophyton, mushrooms, and yellow polyps), assorted snails/hermit crabs/Mithrax crabs, 2 abalones, a brittle star, and one Tridacna derasa clam. All the live rocks are covered with purple coralline algae, as are areas of the aragonite substrate. The back glass of the aquarium is gradually being covered with deep pink and blue coralline algae, the color depending on the depth and what light intensity the area sees. Since installing the reactor, the Euphyllia polyps appear to be opened longer and more full, whereas the Caulastrea appears, as my wife said, plumper and also fuller. All the soft corals are also looking bigger, with the mushrooms spreading out more, the Sarcophyton having small buds appear at its base, and the polyps being longer and staying open and out even when the lights go out. The Tridacna is also exposing more of his mantle. So all the invertebrate life looks very healthy. <Good> My question is will the reactor eventually raise the tank calcium level to close what the effluent is reading? <Yes, though the corallines especially are scavenging biomineral and alkalinity as it's produced...> Or will the coral and other life calcium usage exceed the amount/rate that the reactor is adding, that I should keep adding supplements to speed up the calcium increase to where the reactor can maintain the desired level?  <Not likely necessary. I wouldn't at this point> I currently add Salifert liquid Coral Calcium daily, Kent Tech-M magnesium weekly, and Seachem Reef Builder to the make-up distilled water. Also, am I focusing to much on the what the chemical testing is telling me and should pay more attention to what the tanks inhabitants are doing? <The latter, always> Thanks in advance for any recommendations or suggestions! Kevin <Chat with you soon my friend. Bob Fenner>

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

Calcium reactors and Kalkwasser Bob, My calcium reactor recently broke and I have ordered a new one. In an effort to keep the dKH/ ca rate up I have been adding Kalkwasser to my 300 gallon reef tank. So far I am adding a gallon and a half a day just to keep the dKH at 10. <I've got to start selling chemicals in the trade...> I have however noticed a huge growth spurt in my SPS corals over the last week. Here is the question... Is there any benefit to turning the calcium reactor off every quarter or so and using a Kalkwasser drip for a week or two. Or can I add Kalkwasser once a week or so while using the ca reactor. <Both... and add a bit of calcium chloride when doing this switch over addition> I have asked others and no one can give me an answer. My reef buddy from California has asked you many questions and swears by your advice. So I thought you could give me the straight scoop on Kalkwasser additions while using a reactor at the same time. <Many folks do this... especially in the "forced" culture business side> Thanks for your help and for all the interesting/helpful tips. Sincerely, Neil <Be chatting my friend. Bob Fenner>

Carefully planning the expansion of my reef Hey Bob, So you have answered all my questions about refugiums and the like directly and indirectly.... I am NOT making the same mistake I made when I got into this hobby and just jumping in with little research :) <Plenty of time now... and more than enough new mistakes, omissions to make w/o revisiting the old ones> So before I set up a sump/refugium type deal I want to make sure I am solving MOST issues at once and not limiting my solutions by taking a particular path.... I want to make this reef a little more self sufficient. Already I see that adding chemicals, such as CA and trace elements will become expensive and a burden, worst I could neglect it and that would not be fair to the residents of the reef :) So that being said, I want a Ca reactor... <Good idea> I don't know if you are not permitted to give brand name recommendations but I am asking anyway :) <Yes... it (this site) is of my creation, origination... can/do say pretty much what I think, feel... a few brands are fine, Knop, K2R... and there is sufficient help to consider DIY... see the link to Oz's Reef on the WWM links page> I only have 20 inches in the refugium/sump to fit it... <You mean within the stand? An important consideration... some will fit... or you can place the unit outside of the stand, delivering the effluent via a line that drips into the sump> I am beginning to think that I will have no room for the refugium part if I put a skimmer and a Ca Reactor in the sump side. The tank will only be say about 10 gallons of water in a 20 gallon tank. I thought that I had room for a 27 gallon but then I would not have room to put my hand INTO the tank to do stuff.... I might get a custom one built to the maximum dimensions of under my cabinet... spent too much already to skimp now :) <Or perhaps a more flexible container and through hulls fitted with flexible tubing... Like a Rubbermaid tub?> Ok, So what Ca reactor will suite my needs with the space limitations and a 108 Gallon Reef tank. <Do take a read through a recent issue of FAMA (Freshwater and Marine Aquarium Magazine) and/or the manufacturers listed on the WWM links page here. I haven't reviewed what's available in several months> Other specs: 108 Gal 173 Lbs LR 160 Lbs crushed coral 5 Powerheads 440 Watts VHO Fish and inverts and corals (Anemone, Green brain, Colt Poly, mushrooms, Bubbles, etc) SeaClone skimmer I am dropping (well want to anyway) for a AquaC or other... again space restrictions... Euro-reef would fit too... So what do I need buddy (anything else?).... I want to get it right.... I guess everyone does.. that is why we write you :) <Just the gear that goes with the unit... a carbon dioxide bottle, regulator, needle valve, controller if you really want one...> But don't worry. I have not stopped using my own head and won't rely COMPLETELY on you... or will I, hehehehahaha:) <Now you're worrying me!> Kind regards, Robert Jackson of Canada.... Fun FAQ's Yes people use chillers in Canada too :) <Be chatting. Bob Fenner> and... Ca Reactor cont'd Hey Bob, I have to leave work and was too lazy to reopen hotmail :) How about this reactor... sounds impressive... C-1502 KORALLIN KALKREAKTOR Regards, Robert Jackson <Yes, a good unit. Bob Fenner>

Re: Ca Reactor cont'd I have pretty much decided to get this unit after further research.... My question now has to do with he material to put into it... CaribSea ARM Ca Reactor media says that it DOES have Phosphate and Silica... but less than others.... Is there one that claims they have none? <Not as far as I know> I looked and looked but could not find a Ca monitor... <Ah... most folks settle on a pH monitor for the effluent... calcium can be calculated, adjusted by way of this measure and flow rate> I think this would save money in the long run.... I doubt this exists... I would have found it on the net.... If it is not on the net it ain't real Heheheheh... just kidding... I did find a monitor but it was not meant for this purpose and the range is too low.... only up to 10ppm and as low as about 20 ppb. Thanks as usual.... How can we... your audience say thanks? <You just have my friend> Is there something we can do? <Help others> Regards, Rob <Bob Fenner>
Re: Ca Reactor cont'd (pH and Ammonium, Calcium, Chloride, Fluoride, Nitrate and Nitrite ion electrode monitors...)
Well I found some interesting info... A meter that tests soooo much.... BUT I bet that it will cost an arm and a leg :) <Only way to tell... contact them... more sensitive than you need...> Well here is the link... maybe you are familiar with it.... I still have not found a price for it yet... <Don't know the company... look like the real thing> http://www.spectronic.co.uk/ion.htm <Will have to add in converter for power (from the UK)... maybe ask them via the Net if there are similar, even less sensitive products they know of in the US (if you're here). Bob Fenner> Catch you later, Rob

Re: Found a ton of meters Hey Bob, Found a ton of meters... including Ca :) http://www.spectronic.co.uk/ion.htm  <Ah, will add to the "Calcium, Reactors" FAQs files> I am investigating they further... regards.... <Thank you, Bob Fenner>
Re: Ca Reactor cont'd
Yup I just sent them an email asking about the lack of precision that I require and the power :) <Very well. Bob Fenner>

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

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

Calcium/Ca Reactor Hello Mr. Fenner, How are you? I am extremely glad I found you website, it is extremely helpful/insightful. I hope you can help me with my continuous struggles regarding calcium. Before describing my tribulations with calcium, I want to give you a brief background about my 90gallon reef aquarium. <Okay> I purchased a Marine Technical Concepts (MTC) calcium reactor 3 weeks ago to help combat/mend my low calcium level. Prior to MTC installation, my water parameters are as follows: calcium = 320ppm, alkalinity = 2.97meq/L or 8.3dKH, magnesium = 1320ppm, and pH = 8.2. <Actually, all good values...> Since the deployment of the MTC reactor, the water/operation parameters are: system pH = 8.22, effluent pH = 6.95, alkalinity = 5.03meq/L or 14.1dKH, system calcium = 320ppm, effluent calcium = 420ppm, bubbles/minute = 54, output effluent = 25 ml/minute, and magnesium = 1350ppm. I use Carib Sea Florida Crush Coral Geomarine Formula for the reactor (recommended by the manufacturer). <Yes> The only significant change in water parameter is dKH. My reason to purchase a Ca reactor was to increase calcium, however, it is a still a struggle and have not been rectify (yet?)! I contacted/asked the owner and designer of MTC regarding the high dKH and low calcium level, and they both informed me that the proper usage of the reactor is to measure effluent output flow and dKH, thus, my water/operation parameters are fine.  <I do agree with this> Carbonate hardness is what I should be concern with, and calcium testing is not necessary (they (MTC) do not test calcium)! I questioned their statement; I thought I purchased a Ca reactor and not a KH reactor?! <I understand both your points of view... and yes, you do "need" and want calcium, perhaps more ppm than what you're recording (320)...> This leads me to seek a second opinion. I want to hear/see your thoughts/insights/comments about my current situation. Is it true of what the folks at MTC said? Is there an imbalance of biominerals, if so, how could I correct it?  <A few possibilities... The first and foremost is to try another source of material to meltdown (look at other CaribSea products here... for consistency's sake...) and/or next... lowering the pH of the effluent to about 6.8... via slowing down the flow of water more than increasing CO2 input... and then we'll chat after this... It may well be worthwhile in your circumstances to "goose" the calcium (with calcium chloride, perhaps Kalk, perhaps just CaCO3 powder... )> Is it possible that the high dKH is precipitating calcium in my water?  <Yes!> What could I do to increase calcium? I am concern about the constant low calcium available for my corals, although they appear to be happy/healthy at this time. <Yes... read what you have written... don't be/come obsessed with mere numbers of measures... the health of your livestock is the grand arbiter of all you do with your system... and 320 is not a low number for calcium in an up and going system as yours...> Thank you in advance for your time and effort. Regards, John <And thank you for your clear, concerned expression. Bob Fenner>

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>

Calcium Reactor Hi Bob, Hope all is well. I have adjusted my Knop C calcium reactor to an effluent PH of 6.8 as you advised, and all good. I have noticed a lot of green hair algae, do you think this is from when my effluent PH was running 6.3-6.5?  <Perhaps> Also will the coralline algae still rapidly grow/spread, now running PH at 6.8? <Sure... as long as there is sufficient biomineral (mainly calcium, but about three times as much magnesium...) and sufficient alkalinity, and steady pH, a paucity of competitors, predators...> I also have been having a problem every few days with clogging on the drip regulator that Knop supplied for the effluent rate. Not sure if you have seen this, it's basically a orange screw type valve (the tighter it's screwed in the less fluid comes out and vise versa). If you know of any fixes for this or something I could purchase/make that would upgrade this valve or replace it, please share. <Do know of this design defect... my best advice is to remove it periodically and soak in white vinegar... this dilute, "slow" organic acid (acetic) will digest the alkaline clogging materials safely.> Many thanks in advance, Rob <You're welcome. Bob Fenner>

Calcium Reactors Hello Bob, How are you? Hope all is well. I just finished reading your book (The Conscientious Marine Aquarist)...great book by the way! Wondering if you will write a book specific to reef aquaria only (will definitely buy!)? <Have written most all of TCRA... waiting (and WAITING) on a/the publisher... intend to have the new alliance of Microcosm/TFH produce, distribute, but they are busy... with other projects...> I am in need of your expert opinion/knowledge regarding calcium reactors. I am having difficulty deciding between the Marine Technical Concepts (MTC) Mini-Cal reactor or the Knop C reactor. I have done primary and secondary research about the two reactors, and found pros and cons with the two. <Me too> Fortunately, there are numerous publications/personal experiences available for Knop, and I have seen both products in person. I definitely found significant differences in terms of construction/structure and ease of setup between the two reactors. The MTC reactor appeared to be vastly superior in craftsmanship/sturdiness, MTC does not require any additional plumbing...while the Knop requires a return pump and additional pumping, MTC runs on an Eheim pump...similar to the Knop, MTC have dual media cylinders...second cylinder removes free CO2, and they both are relatively similar in terms of maintenance...although MTC use a lot of nylon screws for the top cover (which require a little more work and care) vs. Knop use one screw.  <Very much agreed here... and these screws are a source of real, make that HUGE trouble... when will our interest learn of other easier, more fail-proof opening/closure mechanisms... like the pool/spa filter industries...?> Moreover, the difference in price is $50, MTC being higher. However, my concern/question is the efficacy of the MTC reactor (unable to find much information regarding this product, unlike Knop). So I decided to visit the folks at MTC and asked about their product and various biomineral parameters pertaining to their reactor. They informed me that the only parameters I should be testing is tank pH, output effluent ~ 20ml/min, and dKH ~ 12...all other biominerals are insignificant (calcium, magnesium, alkalinity, etc.)!---Is this true/accurate?  <What? Not as this is written... of course the alkaline earth materials are important (we could/would call these "dKH reactors" otherwise...). Perhaps whoever related this to you meant that "it is best to measure flow and dKH" as indicators of appropriate use?> I questioned their statement; if the sole purpose of their reactor is to build/maintain dKH, and all other biominerals are irrelevant, then why call it a calcium reactor, why not call it a dKH reactor?  <Oh, oh, we're starting to think along the same lines... what are we having for lunch today Anywho?> If dKH is consistently high, and calcium is consistently low, isn't it an imbalance of biominerals? <Possibly...> Or does a consistently high/stable dKH ultimately center/balance all other biominerals through time/use?  <Depends on a few factors... what you're melting down, what is being taken up, dropping out in the main system...> Is dKH the single most influential factor with regard to a calcium reactor (that is how the folks at MTC make it appear to be)? <IMO, no... one of a few important variables that can be measured to access the system, reactor... I would, do measure dKH AND calcium in our effluents and systems... and pH at times... and am not concerned generally with the dKH being this high, but more so with calcium dropping much below 350ppm... and staying there... in our mini-culture facility (about 4k gallons, mostly hard and soft corals)> Something is amiss, and I am at a lost. Can you please try to clarify the relevance of dKH specific to the MTC reactor? I want a second opinion before making any decision. <I'm in the same club... will gladly "chat" with MTC's rep. on the topic... "If" they have a "standard" reactant that they back with experimentation behind it, a written warranty of how this material will "behave" in all reef/marine systems based solely on dKH measures, I am satisfied (though surprised)... as "all that could go on" in different set-ups with new live rock, plenums, copious growth of mineralizing life... would/could be trouble here. In point of fact, this "linear thinking" (A to B to C) is exactly why simplistic "Kalkwasser" dripping/pouring in is such a dismal failure...> Thank you in advance. Regards, Daniel <Am very sure we'll be chatting. Bob Fenner>

Ca Reactor I finally seem to have the Ca reactor running well. The needle valve that came on the regulator apparently was damaged in shipment and I had a terrible time getting the bubble rate stabilized--it took almost 2 days.  <The needle valve is the single most important piece of gear on these units... have seen ones made overseas that sell for a couple of hundred dollars US...> I'm now running about 30-40 bubbles/min. Effluent pH in the reactor is 6.68, and it's about 6.78 at the point where it's dripping in. Ca level in the effluent is 520 ppm and dKH in the effluent is 19 (I checked these last night several hours after I got the CO2 running again--the needle valve had "shut off" by itself yesterday while I was at work so the reactor really wasn't working until last night--so these numbers will probably increase as well). It looks like the Ca level increased about 20 ppm overnight, but it's still around 310. I'm dripping about 90-100 drops of effluent per minute into the system. <Steady on> Should I supplement at this point with something that won't effect a downward pH to get the Ca level up, or just wait? (I know patience is a virtue in this hobby.) The system pH this morning was 7.92.  <Just be patient for a few days here> Yesterday morning it was 7.96 (but the CO2 wasn't running Wednesday night due to the bad needle valve). Last night the system pH was 8.06 just before lights out. Will these numbers stabilize/increase as Ca and dKH increase over the next few days?  <Should> If system pH is less than 8.06 tonight (suggesting a downward pH trend), should I decrease the effluent drip rate? <No...> Once this is all taking care of itself, it's going to be great--but still a few days to go, it seems. Thanks for your insights once again. <Have I recently suggested you seek other input as well? Am fearful that you may be not getting enough points of view... do you participate in the "reef" listservs? You would benefit and in turn help others by doing so... Bob Fenner>

Re: Ca Level I'm getting a little frustrated with the Ca problem (as I'm sure many are). I finally got the Ca reactor up last night. I checked it today--pH in effluent was 6.65--a little low, I know, but I'm waiting for a new needle valve and can't adjust the bubble rate (about 75/min) below that at the moment. This morning, effluent had Ca of 520 ppm and was 19-20 dKH. I was dripping about 100 drops of effluent/min all day today. I checked Ca level this morning, and it was around 310 or so--it seemed to have increased 20-30 ppm overnight. However, when I got home from work, Ca was at 280! I increased the effluent rate, and added some more of the Tropic-Marin (and tomorrow I need to clean the prefilters again. . .). When I got home a few hours later, the Ca was still at 280. The TM product dosage I used should have raised calc by 20-30 ppm or so, but it hasn't budged. Alk today was at 3 meq/L, down slightly from yesterday's reading of 3.5 as well. I'm thinking now, based on my reading on WWM, that I might need to "jump start" this recovery process with Kalkwasser tomorrow night, as it seems something is "eating up" the calc that's going in there and the levels aren't increasing. My LPS are clearly suffering. Is there any product that I can use to rapidly raise the Ca level without causing major pH or other problems? <Ah... wish I had the time to read through our corr. here... you are very likely actually the cause of the "diminishing returns" of getting (actually keeping) biomineral and alkalinity in your water/system... Very hard to recall what products you used to use... but your pH is not low... and won't get, stay there if you don't drop too much, too soon the effluent of the calcium reactor into it... and all should stabilize in a couple of weeks... be very careful in placing other sources of biominerals, carbonates, bicarbonates... they are negatively interacting...> The pH is a little low tonight--it was at 8.02 when I got home from work. After increasing the calc reactor effluent flow and adding the TM Bio-Calcium, it dropped to 7.92 in a matter of hours. Is Kalkwasser for a few nights, in conjunction with the calc reactor, the answer here?  <No easy, thorough way to answer this here... the overall answer is No... you will likely make alkalinity limiting...> It should help to raise pH and calc levels, and perhaps burn out whatever is keeping my calc level down, if it's being kept down by some chemical interaction in the water.  <It would be more beneficial, safer, and in the long term over-all satisfying to enact some thorough gravel vacuuming using pre-made seawater... to remove a bunch of these reactants from that area...> I'm at a loss here--the Ca level has been plummeting, and nothing seems to be helping. I may also do a partial water change tomorrow to see if that will help--I have a supply of 3-week old premixed water I can use if necessary. <Ahh, good! Now we're getting somewhere.> I will help myself if I just know what is going on here! Thanks for your kind counsel once again. <Clarity is pleasurable, and you are right on the edge of such self-discovery. Bob Fenner>

For the Record (a new, well-upcoming calcium reactor convert) Calc reactor is up and running. Current water parameters: Ca 320, Alk 3.5, pH 7.94. Ca reactor is filled with 12 lbs of CaribSea ARM, 10 CO2 bubbles/min.  <Hmm, only ten...> Recirculating system. Effluent pH is 7.15 for now--but not sure where it will stabilize over the next few days. I'm dripping about 60 drops/minute into the system. (Based on my recent experience, the livestock has been utilizing about 40 ppm/day of Ca--so hopefully these parameters will be sufficient to meet the daily demand and also build the residual level back up, while allowing pH to stabilize and rise as well. . .) <Hopefully> Also for the record--I haven't really had a good amount of coralline algae--still get diatoms and have a fair amount of green microalgae on the live rock. I'll take a "before" picture of the tank tomorrow and an "after" in a month or so and send them to you for comparison to do with as you wish. <Not surprising... given your stated biomineral and alkalinity levels...> All for now! <Be chatting. Bob Fenner>

Mystery Fish & CaribSea ARM I've about come to the conclusion that the mystery fish IS the same species as the one I sent you the link for, Cirrhilabrus cyanopleura. I did a search on the 'net using this genus/species combination as the search query--and I came up with about 15 results. The links that had pictures all seemed to have a different picture for this species. I didn't realize it until I searched this species, but even the picture on the WWM site for this species is different from the one I found yesterday! And the LFS web pages that purport to offer it will have pictures of anything and everything associated with this species! (Calling this species a "velvet wrasse" with pictures that aren't even close to what I've got or anything else I've seen related to this species.) There seems to be lots of opinions and confusion in classifying the wrasses. . . (I think you'd wholeheartedly agree with me on that one.  <Ah, yes... and your identification...> You mention the size and diversity of the Labridae family in your book--which would seem to lead to such a conclusion.) At any rate, a close inspection of my wrasse reveals that the pink head is marbled with very light patches of blue. So maybe in a few months as he ages, the pink will turn completely blue, since lots of fishes in the Labridae family go through color metamorphoses as they age. Or maybe the picture on the link I sent you is misclassified as well. . .as it is inconsistent with the picture on your site. In the wrasses, is it common to have significant color variations within a species?  <Many times... species, sexes, juveniles to other developmental stages, yes> Structurally (and color-wise, with the sole exception of the head) my wrasse is a spitting image of the supposed Cirrhilabrus cyanopleura portrayed in the link I sent yesterday. Hmmmmm. Also, I got the CaribSea ARM in today. Calc reactor should be here tomorrow or Thursday. All of my research up to now has indicated that the CO2 and effluent flow should be adjusted to result in an effluent pH of 6.8. On the packaging of the ARM, however, the manufacturer recommends an effluent pH of 7.5, and claims that this product is easier to melt than other media, and that this will save on CO2. This doesn't seem to make sense--or am in incorrect in my understanding that in order to adequately "melt" the reactor media, the effluent must be slightly acidic? <Both are correct... try the higher effluent pH of this particular product, measure Calcium, what have you... with yes, the acidic (from the carbonic acid/CO2 in solution)/basic reaction...> Thanks for your thoughts. James A. Deets <You're quickly becoming a biologist, chemist and physicist... and honing your discrimination skills... very fortuitous. Bob Fenner>

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

Calcium Reactor Hello there Bob, I have been reading your section on calcium reactors, and notice you say to keep the effluent PH at 6.8. Although the instructions I received with my Knop calcium reactor state to keep an effluent PH between 6.3-6.5 ideally 6.5. I have a mixed reef of clams soft and hard corals with fish. What should I keep my effluent PH. Also what is the difference in benefits/outcome of keeping it at 6.3-6.5 rather than 6.8? will I still get lots of coralline? Thanks in advance, Kathy <A very good question... this preference, suggestion to keep the effluent of these types of recirculated/ing carbon dioxide infusion type reactors is a matter of "safety" as well as expediency... strictly speaking, most folks are well and far better off dealing with a higher effluent pH... enough biomineral and alkalinity make it into their systems for all intents and purposes... and have much less cost (in terms of CO2) and likelihood of problems (algae, pH fluctuations...) at this setting. Do know Daniel Knop of Germany and he is a fine person and engineer... but this is my long-standing opinion/practice. Thank you for asking. Bob Fenner>

Calcium Reactor Hello Bob, <Hi there> I am still new to running my calcium reactor, a Knop model C with an UltraLife regulator.  <A nice combo.> At this time I only use a PH monitor and I try to keep it running with PH 6.5 and an effluent at 2-3 gals per min.  <Hmm, this is a bit low... would shoot/select for an effluent pH of about 6.8...> Although I notice that during the week the regulator constantly jumps up and down @ the PSI which affects the LPM gauge on the left side, causing my effluent PH to jump or drop low leaving air pockets of CO2 in the reactor even though I have a solenoid valve on it. Is this normal for reactors or do I have a bad regulator?  <Hmm, no... more a "design defect"... that I've mentioned to Daniel (Knop) on more than one occasion...> Or is this a simple problem that can be fixed by purchasing a PH controller?  <Hmm, well... possibly... or tweaking flow rate... for now, please just try the not-so-low pH setting... > Also if I should purchase a controller which do you find to be best to work with, Accu-Max Controllers or PinPoint Controllers. As always thank you very much for your input of knowledge. <The latter...> Rob <You're welcome my friend. Bob Fenner>

Ca Reactor Hello again! I've been fighting all week trying to keep the Ca levels up, and it's been a losing battle. (The Calc/water mix I was pouring into the prefilter box clogged the prefilters, and probably somewhat has clogged the biofilter on the DAS system- <You begin to understand my disregard for such "supplementing" practices...> -on the good side of all this, when I was cleaning the prefilters last night, I found and removed a rusty razor blade that some bozo had dropped in the filter box at some point--I bought this tank used and the blade had probably had been in there from the time it was set up. . .) <Yeeikes... good find/removal... > Based on my experience of not finding a practical way to get Ca into the tank, a Ca level that drops about 30 ppm per day, and not wanting to try to become an "expert" in the hazards of dripping Kalkwasser, I WILL have a Ca Reactor by next week. <Yay and Alleleujah! You won't be disappointed... being the "detail" person you are... you will appreciate the tremendous ease, use, safety of this device> I'm not really fretting over what kind to buy, except that it will be recirculating and have an Eheim pump. I'm considering the Canreef, as it looks relatively simple to service and do media changes and has a nice capacity. Also considering K2R. <Don't know the former at all, the second is fine... and have you looked at the Knop line? Try a read through the offerings of the folks companies listed on the Links Pages/Business on the WWM site> I do have a couple of questions about accessories, however. First, solenoids. If you don't have a solenoid on the CO2 regulator, and there in fact is a power failure, what will happen when the power comes back on? <Nothing... they "fail" and "stay" off... (I guess I should say "ideally"... as these electromagnetic switches can fail as well...> What happens if there is a CO2 "overdose"? I'm just trying to find out what I really need. I've found solenoids for $45 or so--so it would either be "cheap insurance" or an unnecessary expense. <There is a wide range of "safety" margin in using these devices... not to worry you, once you establish the needle valve, flow settings there is little that does go awry> And as to the pH monitors that are recommended by you in the FAQs, how are they utilized? Just to monitor pH in the tank, or the effluent, or both? Or are they somehow rigged up to control the flow of effluent or CO2 out of and into the reactor? <Both... need to address many, MANY sections, parts of the WWM site... but these probes can be coupled with on/off valves to deliver more effluent, CO2... I don't use them myself for such... but do rig same up for other "farms", holding facilities... and do use electronic meters for "just testing" water qualities> Thanks again for helping me to sort through all this stuff--my tank inhabitants will be all the more happy once this stage of progression is completed. . . <A pleasure> P.S. RE: the dead plate coral--ammonia, nitrite and nitrate all tested "0" again by the next afternoon. Thanks for "holding my hand" on that one. . . <Ahh, good... as expected> One other question--which may fall into the "stupid question" category. . . <Assuredly, there is no such thing> I believe the biofilter is somewhat clogged, because even after cleaning the prefilters, I'm not getting as much output from the main powerhead as I was previously. Is there a safe way to clean particulate matter from the biofilter media?  <With it up and going on the system? A chemically inert rod (wood, plastic) to "stir it up" gently (half one day, the other half another)... and with the system apart? To gently rinse with white vinegar (dilute acetic acid) and rinse, drain, rinse, drain, add more calcareous media, replace on system> (My guess is that it should be completely left alone. .but more harm in not asking than in asking. . .) Can the biofilter media be "dipped" in system water without destroying or substantially impairing the nitrifying bacteria? (By "system water" I don't mean in the tank, but water that has been siphoned off during a water change.) If this is even possible, I wouldn't do it for several weeks, since the prefilters were just cleaned thoroughly with RO/DI water and any nitrifying bacteria that may have been in the prefilters "helping out" with nitrification will have been rinsed away. <Always a risk possibility... But in systems that are otherwise "cycled" and stable, there is much nitrification going on elsewhere... such that one rarely sees/detects a difference> Thanks once again for your expert and honest advice. <Anytime my friend. Bob Fenner> James A. Deets

Re: Ca Reactor http://www.canreef.com/careactors.htm  FYI--Here's a link to the Canreef Calc Reactor page. I actually found out about this model by reading the FAQs on Calc Reactors on your site. You commented that you didn't like the thumb screws/o-ring closure. <Ah, yes... still don't like these traits> But it seems like a pretty simple setup that's practical--i.e., self-filling bubble chamber, no feed pump needed, about $50 more than the lowest price I've found for the Knop C but much less than others. (I read on some web page selling the Knop that the Knop C requires a separate feed pump--although that doesn't make sense and has to be incorrect, as a siphon (or pressure differential in the recirculation plumbing created by the action of the recirculating pump) should allow system water to feed into it. . .) <Yes, though folks do use a separate pump to good advantage> I'm sure I'll have plenty of questions as I get this all going. . . Talk soon. <Be chatting then. Bob Fenner>

Re: Depleting Alkalinity & Calcium (a new reactor proponent) Hi Bob, <Hello there> Thank you for your suggestion regarding the consideration to procure a calcium reactor. After intense research via internet, LFS, publications, and others (i.e., Bob Fenner), I brought the Knop calcium reactor Model acan.A  The entire package cost $552 (Knop calcium reactor, media, CO2 regulator, CO2 canister, Pinpoint pH monitor, Rio 800, and shipping).  <A better purchase, perhaps never better made.> However, during my research, a couple of sources indicated that the water parameters (pH, calcium, alkalinity) should be ideal reef water quality parameters before initiating the calcium reactor. A Otherwise the system will be continuously off kilter (i.e., extremely high alkalinity but low calcium initially....will continue to have high alkalinity and low calcium post reactor). A Is this true? <Only to a degree... with a few weeks time/use, the system will center itself with the reactors help> A What is the best course of action since my system is not balance, as stated in my previous correspondence (alkalinity = 2.8meg/L and calcium = 320ppm)? Should I artificially increase the alkalinity and calcium prior to initiation? A Or perform a significant water change (25%-30%) without adding supplements and allow the calcium reactor to balance and stabilize itself through time? Or a combination of both water change and adding supplements/buffers to reef conditions? Thank you, Dan <If it were me, I'd simply rig the new system up and fire it over... You will see. No problems/worries. Bob Fenner>

Media for my Calcium reactor I am getting ready to start my Calcium reactor. Please tell me what you feel, or if there have been any studies, what is the best media for my Calcium reactor. Also, I can't seen to do a search on WETWEB any more please help:) Thanks, Brad:) <Many routes to go here with the media question... not just "pure" or easy to dissolve "Aragonitic" materials... You want, need other alkaline earth compounds... I suggest a bit of experimenting with some "standard products" like CaribSea's fine offerings... Try "a bag" of various size/grades of their types and tell me (please) what calcium, strontium, magnesium, alkalinity, pH values you come up with in your particular circumstances (type of reactor, pH of effluent, time in use, amount of reactant...). Please do record your findings in a bound, permanent notebook, in ink. On the "search question", I am sending your msg. to Mike.K my cohort on functionality and looks for WWM (it's only us two...). Miguel, what say you? Bob Fenner, who maybe should private label...>

Opinion? (DIY Calcium Reactor) Hi Bob, What is your opinion of: http://homestead.com/geosreef/reactor.html Thanks, Marty <Looks like a nice, inexpensive home-made unit... with some good concepts (like single pass) and a cheapy "ramp clamp"... Would like to see some plastic clamps on those polyethylene tubing to PVC fittings... and a large funnel for loading the feeder stock in those columns... worth a try. Bob Fenner>

Re: Search for a Reactor, oneself Hi Bob, Well okay. Maybe I need to think some more. I DO want to do what is best for my animals, it's just a question of return on investment. I have checked into the following manufacturers of reactors: Precision Marine, ADV K2R, KNOP, Marine Life Aquatic, Aquamedic, Korallin, Reef Concepts, Canreef. <Quite a review!> While I can find some positive feedback for almost all of the above reactors (I wonder how much was written with a vested interest) <Assuredly, most all...> I have also heard and read that they all perform their task equally well and I should go with the least expensive. I have also read that the CO2 regulator is more critical than the actual reactor in terms of advantages of one brand over another. Your thoughts? Marty <Function the same? Not agreed here... do look for features like the size of the reactant canister, ease/mechanism of getting into it, changing media... needle valve quality, pump quality (get/use an Eheim...)... and finally, just like Dale Carnegie used to write, set a date for deciding (as in nothing is decided till it's done) and buy the better of whatever make/model you find superior... No need to agonize here... keep this issue in perspective... If you were buying a major appliance, like a refrigerator, you would/should give the question the same consideration... features available, utility, cost of acquisition, operation... about, say a thousand dollars worth... More consideration for a car let's say, even more for a home purchase... Affairs of the heart, let's not get started... My point, I sense you are sublimating here... settle on a good choice and be satisfied my friend. Bob Fenner>

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

In Search of Enlightenment re Calcium Reactors Hi Bob, Sorry - for forgetting to include those numbers in the first email. Bob my head now hurts. I've been trying to read as much as I can to make an intelligent choice on a calcium reactor. Then I happened on: http://www.marine-monsters.com/front/products/kalkreaktor.html <Great folks here> Now there are certain things I have held hard and fast to. One is not using any brass in a reef tank for brass is an alloy containing copper. Why then does this unit have a "brass check valve"? <Not to worry... it won't come in contact with the water... you'll see soon enough> Maybe you could just end my agony and say "Marty, buy a ______"
Re: A Search of Enlightenment re Calcium Reactors
Hi Bob, I really must thank you for motivating me to do more research. I have now visited many e-tailers sites (more than I'd care to admit), and read everything I can find (in english) on the web and in NG's. I have come to the conclusion that while there is a lot of pro calcium reactor sentiment out there, the big cost savings seems to be mis-information. Buying consumables for a calcium reactor instead of additives will only save me about $10-20 per year. In contrast, purchasing a calcium reactor, regulator, media, CO2, will cost me between $400-600 depending on brand/e-tailer. I understand that I could DIY for less, but getting all the pieces just right could be a nightmare. This does not seem to me to be a good investment. BTW, I did find out why a brass check valve. <Hmm, would like to see this analysis... counting health/vitality of your livestock? Check valves don't need to be of brass construction...> Thanks for your time and guidance, Marty <Many paths, many roads, many destinations. Which will you choose? Bob Fenner>

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

Calcium Reactors <Thanks again, Bob. Do you have any preferences on a particular manufacturer of calcium reactors? <Not much... DIY ones are about as good as the makes/models that one can buy off the shelf... Knop and K2R are the big winners currently in the U.S.... they will be supplanted soon. Bob Fenner>

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

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

Placing a Calcium Reactor, no problem Hi Bob. This calcium reactor is a bit confusing. I will read more about it, I read about the home made ones in your FAQ, but still a bit over my head. Where would I put such a thing. I have a sump under my tank with a 15 watt UV sterilizer and a protein skimmer. Not much room to put something else under there. <Can be easily remoted, placed wherever a flexible tubing line can be run in/out... Take a look at the Knop) site, link on the pages of the same name: www.wetwebmedia.com> You didn't respond to my question about the nitrites n nitrates not showing up as a color on the chart. Is the Marine Lab testing kit I have no good? Thanks again Steve <Hmm, didn't see this msg. as I recall... Marine Lab's kits aren't great... I would check the checker against another brand.> Sincerely, Steve Rubin <Bob Fenner>

Calcium Reactor Mr. Fenner: Last month you suggest a DIY Calcium Reactor in your answers about my questions involving Calcium Chloride and Carbonate. In the net, OZ Reef, I found a "Recirculating Calcium Reactor" made by Chris Paris for Reef Aquarium Information Depot. It seems good to me, but I wish to know your opinion about the mentioned device. Thanks in advance for your help Fl?io Ribeiro <I am a very big fan of calcium reactors and this design is very workable... definitely the better route to go to assure alkaline reserve, pH stabilization, biomineral availability... Kalkwasser, other additive systems don't even come close in terms of efficacy and safety. Bob Fenner>

Starting a New Calcium Reactor Mr. Fenner I've installed a home made calcium reactor in my system. It has a 2 litres capacity of aragonite, a small Eheim circulation pump (300 l/h), and a plastic needle valve to control the effluent water to the sump. The Co2 is food grade, in a 6 litres appropriated tank, with a pressure regulator and a small needle valve. <Sounds very nice> Initially I tuned the CR like this: - CO2 - 40 bubbles/min. - Effluent - 40 ml/min. <Did you measure the effluents pH? The size of bubbles of course is important with the "count", the outflow sounds a bit high...> Tank initial data, before the CR starts working: - PH - 8.1 and 8.5 at night - dKH - 6 - Calcium - 340 mg/l After 2 days: In the tank: - PH - 8.1 and 8.4 at night - DKH - 8 - Calcium - 360 In the effluent: - PH - 7.3 <This should, could be a bit lower... less flow and a lower pH... right about 6.5 would be ideal> - dKH - 30 With this values I add 40cc. Calcium Chloride in order to balance the ratio between calcium and alkalinity. <One possibility... I wouldn't do the calcium chloride adding as a regular routine though... should be unnecessary with an established routine of melting the aragonite... with which I would experiment as to source/type, size of material... variable in composition, solubility, overall utility> Also I tuned the reactor for 80 CO2 bubbles in order to achieve the recommended PH value less than 7.0 : <And/or slow down the rate of flow/effluent...> In the tank: - PH - 8.1 and 8.3 at night - dKH - 15 !!!  <No worries here> - Ca - 400 In the effluent: - PH - 6.8 <Ah, now that's better> - dKH - 50 - Ca - 600 The corals and the fishes are greater than ever. I don't see signs of stress. ( seven days) <Yes, well done> Because the amount of "alkalinity" is so high I reduced the CO2 rate for 20 bubbles and the effluent flow rate for 20 ml/min., and the result is now: PH - 7.4, Ca - 400 and KH - 15 in the effluent. In the tank the PH is 8.2 and 8.5 at night, Calcium - 450 and dKH 13. I am worried about the KH. <Don't be> Mr. Fenner, what do you think about this values? The hardness is too high . I would expect some raising but not so suddenly. How could I decrease the high hardiness slowly? <Allow the system to re-center itself... this hardness is not too high... a great deal of the mineral can/will be "used" by photosynthates... not a worry> Could you give me some "soft starting approximated values". <Hmm, you've already stated them yourself here... Bob Fenner> Thank you for your attention and precious advice Fl?io Ribeiro PS : I notice today, that the calcium value inside the reactor was 400 mg/l and in the tank was 450. Is there a reason for that?  <Likely the soluble portion of your reactant is decreasing... time to switch it out for some new Aragonitic matter... though there are solids in your contact chamber, their solubility is too low for practical use now.> The amount of bubbling CO2 was intentionally very low ( 10 bubbles) and the effluent about 30 ml/min. Obrigado. <You're welcome my friend. Life to you. Bob Fenner>

Calcium Reactor Mr. Fenner: First thing, I want to thank you for your answer about my new (DIY) calcium reactor. Secondly, tell you that, with your advice, the reactor is functioning much better: <Ah, good> Effluent : ( flow rate - 1.2 litres/hour and 130 CO2 small bubbles/min) PH - 6.8 dKH - 45 Calcium - 700 mg/l Tank: PH - min. 8.2, max. 8.3 dKH - 15 Calcium - 480 mg/l (too high?) <A tad, but no problem... keep it under 500ppm> The problem was my ignorance about the KH expected values. I thought that 12 is the maximum level tolerated. I will continue testing the tank and effluent KH and PH just to find the best tuning. <Yes, a sound plan> Finally, ask you for a comment about my system. All the animals are great. Sometimes I must deal with some microalgae in excess, mainly over the non-sand bottom and on the rocks that aren't yet covered with coralline algae. <Very typical, and not really a problem... just a nuisance> - Volume - 420 Litres (diluted marine natural water). DI from a TWPurifier. Salinity 1024. - 2 Aqua Medic protein skimmers (airstone) Weekly dark liquid production : about 200 cm3 - About 1/3 of the aquarium volume with live rock - About ? of the bottom with calcareous fine sand (1 cm) The other part is covered with coral gravel (1 cm) - Mechanical filtration with medium and fine foam. - Activated Carbon monthly? when I remember.... and only during 24 hours. HW U.V sterilizer - Sump with 60 litres - Eheim 1060 pump - Lighting - 5 full spectrum fluorescent. 1 actinic. 15 litres Refugium with little pieces of live rock, calcareous white sand (10 cm) and a growing fast but yet small Caulerpa taxifolia (not for sure). Little organisms are growing there, copepods and tiny red-brown worms. This refugia is "working" about 3 weeks ago. One 15 watts full spectrum fluorescent is on 24 hours. The water - flow is about 18 litres per hour <Would be nice to have a larger sump...> - DIY Calcium reactor. - Livestock: 1 Zebrasoma flavescens, 1 Zebrasoma xanthurus, 1 Zebrasoma veliferum, 1 Mandarin 1 clarkii, 1 Centropyge acanthops, 1 Centropyge loriculus, 1 Gramma loreto, 2 Tridacna crocea, around 40 small Hermit crabs (Calcinus spp. collected here in the island coast) , and 2 big ones (Clibanarius spp.) , 2 Lysmata amboinensis, 1 red local "Atlantic" seastar? (similar to Linckia), 1 Tubipora musica, 1 Catalaphyllia jardinei, 1 Clavularia viridis, 2 Turbinaria sp., 2 Palythoa sp., 1 Sarcophyton sp., 1 Tubastrea faulkneri, Several Actinodiscus. Mr. Fenner, I admire very much your work. You are doing a great job for this marvelous hobby and for the nature protection. Your web site is full of precious information about what we must not do or buy. Your explanations are clear and simple, an exclusive attribute of people who have good knowledge. I hope that your care lasts for long ! Happy New Year Fl?io Ribeiro <Thank you for your kind, encouraging words... mean much to me. Bob Fenner>

Calcium Reactor (when to implement) Bob, I have purchased a Calcium Reactor for a new reef tank that I'm setup up. Being that I don't have facilities to cure my live rock I will be curing it in the tank for a week or so then doing a 80%+ water change adding live sand and starting the cycling of the tank. When would be the best time for the implementation of the Reactor, should I have it up and running during the curing of the rock, wait until after the rock has cured and the cycling starts, or wait completely until the cycle has completed and livestock is begun to be introduced. Thanks, Jason >> If it were mine... right now. As soon as possible... ahead and during the live rock cure... Bob Fenner

Not cycling a calcium reactor Hi bob, i hope you enjoyed your trip...i ordered the Knop calcium reactor which should be here any day, how long till the tanks water conditions are stable, do these reactors need to cycle like regular filters?...will the cycle kill what i have in the tank now?...when i finally buys corals, do they need to be acclimated like fish do? >> No cycling involved... more like a chemical feeder... Acclimating some of what the trade calls corals is a good idea... to ascertain whether the specimens are healthy/going to make it... and possibly to isolate unwanted "hitchhikers" that may inadvertently be traveling with them. Bob Fenner

Calcium Reactors Bob, do you know of any articles and/or literature about calcium reactors. I really want to get one but before I spend $500 I'd like to do as much research on its advantages/disadvantages. are these things really that good? i heard they maintain your reef water perfectly, aside from water changes, of course. any websites that you know of that has literature on these things? oh, and could you recommend any particular calcium reactor or are they all they same? >> There are numerous (hundreds in my files) of articles, promotional materials pieces on Calcium Reactors... I would take a look at the last year's worth of hobby magazines in all the languages you understand... And use the Internet to look at the manufacturer's input... and hobbyist opinions on their respective features, utility. Bob Fenner, who has seen the near future of easy reef keeping... and it is in large part these devices.
Re: Calcium Reactors
Hey bob, i have yet another question regarding my investigation on purchasing a calcium reactor...the Knop calcium reactor people said i need a sump to drip the reactor into. can i make a sump just using a 10 gallon tank, with a powerhead in the tank and a pump of similar size in the sump?. or do you recommend using an overflow into the 10 gallon tank and a pump in the sump?... <Yes... I believe in gravity> also, could i put substrate/rock/or anything else you think would be good in the sump for a better system?... <Certainly... good place for a continuously lit Caulerpa, live rock sump...> finally, i don't know if you know anything about the Knop reactor but i have just seen a picture of it and it doesn't look like it pumps water from my system, through the chamber, and back into my system,. it just looks like it holds a certain amount of water, which would need to be replaced every so often, is this true?... <No... there is a pumping mechanism for moving water into the reactor... and slowly back out of it to the main system... or a sump attached to it...> is there any advantages or disadvantages of this type of reactor with any others...thanks again....Jeff  <Many things to say here... what do you think? What are the advantages of a double-loop recirculation arrangement? Use of the carbon dioxide? Control via the valving of effluent pH? Calcium, alkalinity tuning...? Bob Fenner
Re: Calcium Reactors
Hello again bob...i talked to the sales rep at the Knop calcium reactor place. he told me that i would need a sump to drip the calc reactor into, <Hmm? Nah... can be dripped into main systems...> or, which i suggested, to put the system on a shelf higher than the tank and drip it into the tank, which he said would work as well...my question is what's the difference in dripping in a Kalkwasser solution compared to the reactor solution... <the Kalk's relatively toxic and insoluble... the calcium reactor material not only has biomineral (calcium, magnesium, barium, strontium...) but alkaline reserve (carbonates) as well... compared with Calcium hydroxide (aka Kalk, more akin to oven cleaner...) which only has calcium and hydroxyl ions...> I'm sure with some experimentation and practice, i could get the art of adding Kalkwasser to my tank down to a science to keep my calcium level at a constant. why then would i spend all of that money on a calcium reactor?... <Pls see our site re this issue: Home Page > s the only difference between the two, besides a huge price difference, is the convenience of not having to mix the Kalk solution and measuring it all the time??.. <Far from it... the reactor adds most everything biomineral AND alkalinity wise a captive system needs/uses... the Kalkwasser habit see-saws a system back and forth, rendering depletion of alkalinity, other biominerals... poisoning, to a degree selectively biomineralizing life... w/o live/dead rock and other calcareous substrate, Kalkwasser would kill off everything in such systems...> i apologize for asking you all the time but i sincerely trust your opinion and value it before i would spend all that money on a reactor, i just want to be sure my investment is a worthy one...thanks again >> <And I appreciate your interest and trust... Read, study, converse with others till you've made up your own mind on which way(s) to go. Bob Fenner>

Calc reactor for 120g Reef I am torn between the Knop model C reactor and the Korallin Kalkreactor model C1501.The Knop is about $100.cheaper if that means anything. Korallin says that a PH controller is not required as there is no chance for the non- dissolvable excessive CO2 to escape in the system unlike ALL other brands and is the most maintenance free setup in the world! Do all other reactors need a PH monitor.  <It's a very good idea> I would appreciate your comments on what Korallin states and your recommendation. <Have seen both, know the Knop product... and know it to be reliable> Also i plan on have mixed animals in my 120g reef ,soft, hard coral, and clams. metal halide /power compact. I have been told that I will need MH250watt/10,000K w/PC 7100k.What do you recommend and is there a brand preference? Thanks >> This lighting mix is fine... no brand/manufacture preference... the actual components are made by very few companies... most everyone has learned how to "put them together", do the sales, distribution.. . Bob Fenner

Expense of a Ca Reactor... compared with...? I have a 55 gallon with 2 Fluval 403, a Biowheel, protein skimmer, and UV sterilizer. I'm interested in getting some corals generally polyps, hammer, leather, and some clams). i investigated calcium reactors with CO2 units, which sound great, but are very expensive. I read that just adding limewater with a drip dosing system and an electronic pH monitor is just as good and a hell of a lot cheaper. <Can be just as serviceable... given knowledge, testing... diligence... In the long run, not less expensive... as you'll come to find out> it said to just drip this limewater to top off any evaporated water will work just fine. any comments on this?  <Yes, it's wrong> Also, what about Reef Solutions calcium chloride liquid concentrate over making Kalkwasser limewater?  <IMO both calcium chloride and Kalkwasser (calcium hydroxide) can/should be used in tandem... to render what which has sufficient biomineral content, yet allows alkaline reserve as well... both are necessary for the care, growth of biomineralizing organisms> does it just sound easier but not as effective?  <Not as effective... does nothing to add other biominerals other than calcium... for instance> do i also need to add a trace element liquid in addition to everything? >> <Possibly... depending on the types of life you keep, your set-up, feeding... how much you're going to "boost" the system with intense light, high temperature... Bob Fenner, who asks that you read the pieces on these topics, here: Home Page 

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

Calcium reactors, etc. hello, I have just finished reading your book, for the third time! Excellent reading; I keep going back to it for reference constantly. <Wowzah> In my quest to round up all of the equipment for my reef tank I think I will have a calcium reactor running from the start. I have seen some simple DIY reactors that I feel I could make easily. My question is, do you have a preference to the style: single pass, multiple pass or recirculating? <Recirc. is best> Should it be ran by a controller or timer? <Controller is best...> Does this negate the use of Kalk in the make-up water? <Nope, but you will find the Kalkwasser superfluous in short time> I'm jumping way ahead of myself now, but when I purchase the first fish for this I was leaning towards the Yellow Tang. In your book you state many good reasons for choosing this fish. Will other fish from this family be a proper replacement instead? <Sure, other Zebrasoma, some of the similar appearing, and "resource partitioning" Acanthurus> Something like the Sohal, Kole, or Scopas? If the Yellow  is a better choice, then Yellow it is. <Hmm different animals, but the last two about the same purpose, temperament> Thank you for your time, it is appreciated! Greg Lindstrom
You're welcome, Bob Fenner 

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