For those who run kalkreactors and calcium reactors..

[Doug]

Using kalk only will maintain add calcium and help with alk. levels but I have always found the alkalinity to drop in kalk only tanks. I and others doing the same, add a buffer once a week or so, to maintain alk.

My co2 reactor, maintained both my calcium and alk. as Brad mentioned his did. I found my alk was always on the higher side, pushing around 11.2dkh.

I think most running a co2 reactor, use a kalk reactor or drip, to help boost calcium in a heavy demand tank and also as mentioned, to help with ph levels. However I know of several co2 reactor users who dont follow this idea, as there reactors are sized large enough to provide calcium & alk, plus they also seem to maintain high enough ph levels with no kalk.

I like kalk myself, as its cheap and easy to use. I have never used a reactor though, just dripping now or mixing it in my top off tub when running my larger tanks.

I would say keep the co2 reactor running the same or back it down a bit and keep using a good kalk mix to bring calcium levels up, with perhaps a bit of Reef Advantage or whatever you use, to increase the calcium levle some.

Whats the alk. reading on the reactors output? If mine got a bit ot high, I think I decreased the co2 amount a little, which usually lower it. Cant remember for sure but think mine was running in the low to mid 20,s dkh area.

[Delphinus]

Originally Posted by reef_raf

Well, kalk will add both Ca and Alk, as will a Ca reactor. Tony, on my 150g, once I set the parameters where I wanted them using Kent A&B, my Ca reactor was able to maintain those levels all the time. I never needed both, and that was with a lot of SPS growth. If your Ca reactor is sized to your tank/bio-load, maybe just try running that AFTER you set the right levels.

Hi Brad, thanks, that is basically what I'm trying as I try to dial in the two reactors together. (Ie. using the two-parts until I get Ca=390 and Alk=3.0, then let the reactors try to maintain after that point.) It's just that over time, Ca will will fall, and Alk will rise. Which wasn't quite was I was expecting, I was expecting both values to rise (or drop) together. If I run the kalk by itself both values will drop. If I run the Ca by itself I should theoretically be able to retune to the system's draw rates but I was hoping to add kalk to the mix because it helps to precipitate out phosphate (or so I thought).

I dunno maybe I'll just give up on the kalk for now. It's not like I have any SPS left, so the draw should be fairly low anyhow, but I was hoping to maintain the levels for the benefit of the other things I have left (clams and LPS).

[untamed]

Of course, it could be something related to the Ca/Alk that your specific tank uses. It think it is fairly accurate to say that both Kalk and Ca reactors deliver both Ca/Alk in a mostly balanced way.

Holmes-Farley also says that often having one of these parameters a bit low is an indication of not enough of the balanced Kalk or Reactor...as opposed to concluding that you need to chase Ca or Alk separately.