kalk reactor vs Ca reactor

[eleyan]

I noticed that a number of people on this forum stated that they replaced their Ca reactors with Kalk reactors.What are the advantages of kalk reactor vs Ca reactor. I guess the complexity is one of the main things (Ca reactors beeing more complex because of CO2 and PH control), but is there any other functional advantages?
Also, all plans I've seen for Kalk reactors work of the fresh RO/DI top off water supply, while the Ca reactor recyles the salt water from the tank through the reactor. Can the Kalk reactor be supplied from the salt water in the sump instead of freshwater, or will kalk not disolve in salt water? Can you use a small pump in the sump on a timer to push a small amount of tank water through the reactor every hour or so to mix it with more Kalk?

[Richard]

Kalkwasser needs to be mixed with RO or DI water to create a saturated solution which then goes to the tank. Mixing with saltwater would not work well. You would probably just kill your alkalinity by creating alot of calcium carbonate.

Kalk is primarily for maintaining calcium levels. One big advantage of Kalk is that it precipitates phosphate. Plus IME my tanks have done best when I have consistently dripped Kalkwasser. Very tedious without a kalk reactor though.

[Saltyintraining]

I am now running both. I had problems keeping up my PH with only a calcium reactor. With both now I have no problems. Calcium stays where I want it and so does Alk and PH.

[wkopplin]

Does Matt make kalk reactors too?

[Tim Marvin]

I run both on different systems. The kalk is much easier to use and does a much better job as far as coralline growth and overall tank health IMO. I haven't been overly impressed with the calcium reactor it does grow coralline at a slower rate and PH stays at 8.2-8.3, although it looks really cool and high tech.
Matt makes reactors and skimmers. The best in the industry, hand made to PERFECTION. I use one, Jim uses one, John M. at Arizona reef farm use one now, with more to come. If you want one, get it now before he makes a name for himself and they go on back order and the price sky rockets.

[matt]

Wow, thanks, Tim. Maybe a slight exaggeration.....

Anyhow, I have not yet made a kalkreactor, but I suspect it's only a matter of time. Salty, you're the first person I've ever heard say that he had trouble maintaining Ca and alk levels with a Ca reactor. My only guess is that either you were using not great media, did not have the reactor set for best efficiency, or had a reactor that wasn't designed well or working right. The ability to REALLY pump out high dkh and Ca levels is the best thing about a Calcium reactor. I had trouble maintaining levels, especially alk levels when dripping KW, although I did not have a kalkreactor.

There are some really good things about KW, though. Properly dosed, it does really help with ph, and does seem to stimulate coralline algae growth. My guess on this is that coralline algae must prefer a high ph environment. Coral growth, on the other hand, seems to be much better in my tank with the Ca reactor; one reason for this is the abundance of carbon dioxide for use in photosynthesis.

The idea of using both is at least theoretically strong, because the Ca reactor provides plenty of CO2 for the hydroxide ions in KW to form bicarbonate. Lack of CO2 is a common problem in KW only systems, and is probably the cause for low alk levels in some cases. Another way of dealing with that is to spike the KW with vinegar, which I used to do and it really helped. What a PITA, though, every other day mixing KW, measuring vinegar, letting it sit, filling the auto top-off. The Ca reactor maintainance consists of taking a look at the bubble counter every so often to make sure CO2 is flowing.

Phosphate removal is an issue; some people with high bioload tanks running a Ca reactor do have to deal with phosphate in other ways. I do this with a caulerpa refugium. What I've read is that KW only helps in phosphate removal if the KW is dripped into a skimmer or some very high turbulence; something about gas exchange as the KW enters the water, but i can;t remember the exact reaction. Maybe one our chemistry buffs can help.

[Instar]

You got it right Matt. KW only reacts in the local area where its dripped and in order to mix, degasse and dilute it so that this is not going on when that part of the water gets to the tank, it should be in a turbulent high flow area. A number of things are precipitated or gassed - phosphate, other wastes (the infamous metals), etc. However, your skimmer will remove the phosphate, so even though there is a side benefit to KW with some PO4 removal, I would not drip KW because of that. Almost evey one has learned to run a refugium at this point, so between that and the Matt Monster skimmer, PO4 removal is of little concern in dripping KW. PO4 is concentrated in the skimmate and I can test for it with good recovery. I can not recover any in my tank or other peoples tank water who run skimmers b/c its below my instrument range. There are other things that thrive on the organic waste byproducts of fish and decomposition. On one note: People with mixed populations of mushrooms, zoos and stoney corals will find that their mushrooms and zoos grow faster if not all of the organic wastes are removed. One of the purposes of a mixed population is to control those kinds of things. Some ricordias come on encrusted rocks that look like rocks but are really encrusted oysters. I let the animals do the job of soaking up some of the wastes and I very rarely drip KW, so far anyway. Things can change, so I test regularly. Its always possible I'll modify my methods, depending on consistency of test results for calcium. I've seen excellent coraline with and without KW.

As for coraline, it grows in ultra clear water (with a good calcium content) the best. One with all the amines removed (yellow and green tints). KW helps with that and so does running a good grade of activated carbon, either with a skimmer. A calcium reactor is not going to clear the water of the dyes. Either way, KW or carbon, you get clearer water and more coraline providing your calcium and alk are consistent and not depleted. Mushrooms, clams, oysters, etc., with refugiums can also clear, but, there are many variables that may be influenced by the way the support pieces of equipment are set up on a system. I use carbon and a skimmer and caulerpa and oysters/clams/mussels and others to clear water and help use things like PO4, etc. Water changes will also help clear the water when done regularly and this alone (providing skimmers are used)
can provide good coraline growth without KW.

[eleyan]

Wow, Your kong-fu very strong .. :) It sounds like its almost a tie, but more people prefer the Ca reactor. I'm trying to summarize the pros and cons for each just for my sake and anyone reading this thread:

Ca reactor:
Pros:
- better control over Ca (Kh and PH too)?
- closed loop (running of the tank water, so is not dependant on top off water)
- it sounds like it suppliments more than just Ca?
Cons:
- Need CO2 supply.
- More complicated and maybe more pricy?
- Need to control two variables, CO2 flow to control PH in reactor + water flow rate to reactor

Kalk reactor:
Pros:
- Kalk raises both KH and Ca?
- removes phosphates
- simpler design, with less variables to control (it sounds like the water flow rate is the main variable)
Cons:
- because it works off the top off supply, you can't conrol the flow rate that much (Basically, it depends on the evaporation rate in your tank). In my case, my evaporation is very low, so my top off water is only about 1G to 1.5G per week. I've been using a manuall top off container connected to a float valve, which is similar to the functionality of the reactor, but does not keep mixing the kalk that settles in the bottom, and that does not seem to maintain my Ca level. I have to suppliment with Kent A+B to maintain both Ca and KH
- you either need to hook it up to your RO/DI supply or hav another container to hold the fresh water. You cant run it in a closed loop fashion like the Ca reactor because Kalk has to desolve in fresh water and not salt water ?

Matt,

I will have to get in touch with you to see if you can hook me up with a small Ca reacor (for a 72G tank). My main constraint is that my tank is in my living room and my wife will kill me if I have any equipment sitting outside the stand, so I have to get one that will fit in there.

Thanks ,

Nadeem

[JimD]

Hey Tim, whered you get your kalk reactors from? lol

[Tim Marvin]

Top notch JimmyD's.

[matt]

Eleyen;

I think you're pretty close on the pros/cons. I would add the following;
Ca reactor:
More expensive initially
Probably better able to maintain levels in a high calcium demand tank
Once adjusted correctly, basically no maintainence
Ph issues in some tanks, especially those without skimmers and/or refugiums
Dependent on skimmer/refugium for phosphate removal

Kalk reactor:
Less expensive initially
Slightly more maintainence
Typically no ph issues, although in a small tank, I could imagine some serious ph spikes unless you have a very reliable and slow delivery set up.
Phosphate precipitated, although I have a feeling that skimmer/refugium is a much more efficient way of removing phosphate, UNLESS you can drip the kalk into a skimmer input.

FWIW, I'm not convinced that there is any problem with runnng a low ph (7.9-8.2) as long as it's stable. In fact, if you have bioload issues, nitrogen compunds, especially ammonia, are much more toxic at a high ph. My reactors have a footprint of about 8" by 11", minimum height of about 18". It's possible to make the footprint 7" by 7", and plumb the pump remotely if needed. I have stand space limitations, too, so i built a small stand for my reactor, and put stuff underneath it. In fact, you could put the pump underneath, keeping the footprint really small, but raising the minimum height about 6".

[dan]

sure is nice to get all this info. thanks guys!!

[GaryP]

I've never run either, but I would think there is a greater potential for something going seriously wrong with a kalk reactor due to the potential for overdosing with Kalk and getting a high pH spike. Am I wrong here? I'm thinking from a pure chemistry standpoint. Kalk is a strong base whereas CO2 (carbonic acid) is a weak acid.

Gary

[Jimnorris]

Just me but I like kalkreactors way better than calcium reactors. I currently have two JIMDs and one PM. Here are pictures of both up and running. The first is JimDs and the second is PM (wife just brought it for me--birthday)

[Jimnorris]

PM unit

[Tim Marvin]

I'm a kalk reactor guy myself.

[Richard]

Well I'm planning on setting up my 215 with a kalk reactor and no Ca Reator. So I guess I'm a kalk reactor guy also. Just what this hobby needed...another debate.

[Tim Marvin]

LOL.... More than one way to skin a cat.

[JimD]

Jimbo!, That PM looks sweet! Is it a PITA to recharge? All I get from my wife on my birthday is a big ole knot on the head. lol

[Jimnorris]

Jimbo,
Actaully it takes about the same amount of time to recharge it as yours does. On the very top of the unit it has a plastic screw about 2 inches in size with a rubber o-ring. I never shut the unit off. It runs 24/7. The mixing pump I have on a timer to come on 4 times aday for about 15 minutes long. It is design to drip even while mixing??? I have test the PH of the drip on several different times. All read 12.2 to 12.4. It takes about 2 to 3 CUPS of kalk to charge it!!!!!!
Jim

[eleyan]

OK, I was almost sold on Ca reactors. Now I'm back on the fence. I belive the scor now is:

Kalkies: (3)
Richard
JimD
Jimnorris

Calcies: (3)
joshua
Instar
Matt

Both: (2)
Saltyintraining
TimMarvin

Undecided: (3)
dan?
GaryP
my self

I have a question for all of you Kalkeis, The Kalkwasser mixing instructions say to use a max of 2 spoonfuls per Gallon of RO/DI watter. I'm guessing that any more Kalk above that will not disolve and just end up at the bottom of the container. I'm asking because Like I mentioned above, I have a setup with a float valve and a small container to dose Kalk, and my evaporation rate is only 1G-2G per week, so at the 2spoonfull rate, I was not getting enough Ca. Will a Kalk reactor be able to saturate the water with more Kalk? or will it be the same results but automated better?

[matt]

It depends on your calcium demand. What I'd like to know is how you're getting only 1-2 gallons evaporation per week on a 72 gallon tank. On my old 45, i was evaporating more than that in a day, replacing all water with vinegar spiked KW, and still could not keep up with my calcium demand, especially carbonate. Typically, if you have a lot of stony corals, coralline algae, and very bright lights, you'll have a high calcium demand, as this demand is directly related to the amount of photosynthesis ocurring in your tank. I'm having trouble envisioning a brightly lit 72 gal tank with good gas exchange and water movement that only evaporates 1.5 gallons a week.

[eleyan]

Matt,

Actually, my lighting is not that hot (220W PC) . Most of my stock is soft corals and corals that do not demand high lighting. Also, I have the top covered with glass, so all evaporation is taking place in the sump. My tempreture is about 79-81, so I haven't had the need to open the top, I have a sleeper goby, and I don't want him to jump. I have about 1300GPH flow in the tank, so I don't think its a gas exchange issue. My old tank (110G) I didn't have the top on, and evaporation used to be much more (5G-6G a week). I was able to keep my Ca up with the float valve method back then.
In my new tank however, I haven't been able to keep up with Ca demand with the top off Kalk water only, so I've been supplmenting it with Kent A/B and Ca Buffer daily. That's why I'm looking for a way to automate it better (Kalk reactor or Ca reactor)

[Richard]

With only that much water loss, kalkwasser is probably a bad choice. I lose about a gallon/day on a 30 gallon tank and was losing 2.5-3 gallons per day on my 140. Actually, I lose more than that on a covered 30 long that doesn't even have a sump.

It doesn't really matter how much kalk you mix with the water. Saturated is saturated. I think the instructions of 2 tspns per gallon is just marketing at work...use more kalk, buy more kalk. When dripping kalk manually I use just enough that will dissolve completely, about 3/4 tspn per gallon. It's easier to avoid adding undissolved kalk that way.

Matt, I tried the vinegar method for awhile and did not get the the same results as when using just straight kalkwasser. I even ordered some lab grade calcium acetate (what you are creating with calcium hydroxide and vinegar) and got the same poor results. Do you think the vinegar could have been contributing to the loss of carbonates?

[eleyan]

I guess this rules out Kalk reactors for me based on my current evaporation rate (unless I add MH or open the top).

Matt,

Thanks for the info on the sizes of your reactors. I'll have to measure the area under the tank to see if I can fit it in there. The bowfront tank looks good, but the area in the stand is very inefficent because of all the curves.

[matt]

Richard;

I found that adding vinegar helped, because it did a couple of things. One, it increased the amount of KW I could safely add to the tank by lowering the ph of the KW. Two, by providing a source of carbon for the hydroxide ions to form carbonate, it raised the dkh. I found about a 15% increase in both Ca and dkh with vinegar spiked KW; I used about 20ml/gal of water. Any more than that and I didn't get any further improvement and my ph started to head south.

The problem was as my corals grew, the calcium demand in my tank increased. Eventually KW just could not keep up, and I had to supplement with calcium chloride and sodium bicarbonate. When I got the reactor, for a while I was using the reactor and dosing KW. I gradually decreased the KW and increased the effluent flow on the reactor until I was just using R.O. water for evaporation replacement. If I had a convenient way of adding a little KW to my system, I'd probably do it; it really does seem to stimulate coralline algae growth. But, on my new system, I'm fnding coraline spreading pretty rapidly over my new rocks and on the glass. Until recently, I had 2 urchins in the tank that were primarily coralline grazers. Now I have only a diadema urchin, which is a GREAT general algae grazer and seems to prefer filamentous algae, and is not interested in the coralline. Due to the light, though, it's mostly green coralline algae, which is fine by me.

[Richard]

I've been using Anthony Calfo's Slurry Method with no problem. About 1/16 tspn Kalk in a cup of RO/DI water, then just pour it in the tank. Although I use about a quart of water just to be safe. The amount of kalk & water can be adjusted based on water volume. Best to have a ph monitor to determine the right amount - ph increase no greater than .2. You also need to make sure that all of the kalk dissolves so your not adding solid calcium hydroxide to the tank.

[AlienAnchovies]

question, do they make kalk reactors from smaller tanks say in the 20 to 55 gallon range or are they just meant for the huge monster systems

[malofish]

Just found this!!! I'm setting up a 50 to 55 gallon clam tank, I will be buying it's own RO/DI unit, that's why I'm thinking about a kalk reactor. Does anyone know why I shouldn't be using one O'these on a calm tank??? If so please tell me now, cause I think that I'm convinced that kalk reactors are the way to go for clams.

[eleyan]

I don't see why you can't use a kalk reactor for a clam tank.

[Tim Marvin]

put me on the kalk wagon.