There is no doubt that Kalk can be used effectively to supplement Ca/Alk. A Ca Reactor can also do this on it's own, but the combination of both methods has less impact on the tank pH than either method alone. I'm right now bringing my Kalk reactor online and I'll be able to share with everyone actual affects it has on pH.

Neal asks...
"I now have a calcium reactor up and running.
will that help with the alkalinity? or better question would be how do u control the alkalinity."

Joe Reefer has provided a good link to learning how to run your reactor. I'll just add that the reactor can be adjusted to supply more or less Ca/Alk. The only way you are going to know how much Ca/Alk your tank needs is to get Ca and Alk test kits and use them. Then you will know if your reactor is set correctly or not. WAG is no way to setup a Ca reactor!

Wag?

Kalk seems to raise Alkalinity and maintains it quite well but not so much for Calcium levels. Calcium reactors raise Calcium levels and maintains them well but do not maintain Alkalinity as well as Kalk. Run both and its the best of both worlds! :mrgreen:

Hi Neal,

Alkalinity is (IMO) one of the most important parameters to track if you want corals to grow.

Ca and Alk have a bit of a see-saw effect. You need alkalinity in order for calcification to occur. If Ca is the raw materials corals need to use up to grow, Alkalinity is how they can pay for those raw materials. Ie, if you don't got the cash all you can do in the shop is look at what is for sale.

Beyond that, as stated already, things like NO3 and PO4 need to be as low as possible as they interfere with calcification; Mg is important for maintaining Alk, and of course Ca and Alk.

You'd be surprised how quickly Ca can be used up when Alk is good. In my ritteri tank which has no SPS, the only real consumers of Ca and Alk are two clams, and if I keep my Alk at 3.5 meq/l (note - to convert from meq/l to dKH, multiply by 2.8) then the calcium draw is 10ppm per day. Ie, without adding any Ca additives every day, the Ca reading decrements by 10.

Add a few SPS into the equation and they will suck up that Ca and Alk like crazy. This is where the convenience of a calcium reactor comes in. However by no means is a reactor mandatory of course, but not much compares to the convenience factor of a dialed-in reactor.

Bear in mind though that it's a bit of art as well as a science. (Hi Wendell! I'm stealing your quote.) You can have nearly perfect parameters and not maintain SPS. (Welcome to my world, BTW.) There's a lot more than meets the eye, pests, predators, pathogens, allelopathy .. and so on and et cetera.

Actually, allelopathy is a big one that is easily overlooked. Allelopathy is the ability of one organism to impede the growth of another competing organism. And there's a LOT of it going on in the reef. Have caulerpa? Guess what, it impedes the growth of SPS. Have softeys? Anemones? Etc. etc. Basically a "mixed garden" approach (ie. a little bit of everything - soteys, LPS, SPS, .. etc.) is sure to have a lot of it going on. Short of maintaining systems that are designed to favour one thing (ie. softeys tank, SPS tank, no overlapping) there's not a whole lot I think you can do. Water changes, carbons, maybe resins .. It's not a perfectly understood phenomenon among even the more advanced aquarists (again IMO - hope I'm not insulting anyone).

Anyhow all I really intended was to say "Alkalinity is important" and it seems I branched out a bit. So I'll stop yakking for now. Anyhow, good luck. I'll tell you it sure is a great feeling having a nice SPS tank. It's been a while since I was there but I remember the good old days:
http://members.shaw.ca/hobiesailor/a...kshots/75g.jpg
(My 75g as it was in 2004 before I moved. One day I hope I'll be back there again..)

Ok, there were 2 pages of posts past the part that I was responding to. So that part where I said I'll stop talking? Yeah, um .. ok, I'll stop talking after THIS post.

A calcium reactor will add Ca and Alk in a balanced manner. Ie. for every 10 ppm Ca, you get 0.1 meq/l.

Kalk impacts Alk more directly than Ca.

Running both is, as Harvey said, really the best of both worlds. It's not just pH control, for one it helps maintain Alk, but also kalk also helps precipitate PO4. Also, I'm not sure about this 100%, but I think dripping kalk helps your skimmers skim better.

There! Now I've said my piece and I'll stop now. One thing to bear in mind that with my comments, I'm a blind man telling you what an elephant looks like. I haven't had a decent SPS tank in years. I have no idea what I'm doing wrong. So don't listen to a word I have to say!

I just giggled in class...oops...you are too funny Tony :lol:

Also recommend the books by Calfo and Borneman (and actually had them both out this morning looking into Elegance).

Had my reactor for a while now and biggest thing I can say on it is it will maintain the levels but not really raise them very well. When I first set it up tried driving my Ca up with it but just ended up raising my Alk at a higher rate, though could be was low on Mg. My pH is on the lower side (8.1) but don't think I'll be trying the kalk to compensate.

Good cost on Ca and Mg supplements from littlesilvermax.

so besides the chemicals and such...
what are people's opinions on bio loads?
would it be better to have no fish in a tank with SPS??
thanks again
Neal

I think it's beneficial to have SOME sort of bioload. It's my understanding that corals use fish waste as a food source. It's when the waste is left to accumulate, producing nitrates, etc., that it becomes a problem.

I agree with Drew. It's more about managing and balancing the nutrient intake/output rates. Sure, a smaller bioload means you have less to take out, but I wouldn't say it makes things any easier or harder either way. It just depends on the situation and equipment available and maintenance routines. Some of the nicest SPS tanks out there have a LOT of fish.