Raising Ca & alk -- can I add something other than kalk?

[ACBlinky]

I'm hoping someone can enlighten me. I drip kalk on my 90g daily (about 1g/day, with 2tsp kalk powder). Today I measured levels (for the first time in a long time) and was not pleased with what I saw:
Ca 300ppm
KH 2.4meq/L
pH 7.9 (2h after lights-on)

I need to raise these, but don't want to hurt anything. The only things using up Ca in my tank are a single small fox coral, a 6" patch of Halimeda macroalgae and 3 cerith snails, but they seem to be taking it up faster than I can supply it via kalk.

My question is this: can I use CaCl to raise Ca, and Kent Superbuffer (carbonate, bicarbonate and borate salts) to raise KH? I'm afraid that adding either of these will cause a snowstorm and plummet Ca levels down to nothing, since I've been adding kalk for so long. I was thinking of adding them on separate days, and obviously not on the same day I drip kalk -- will this work, or is it asking for serious trouble?

If there's nothing else safe to use, is it safe to start dripping more kalk, say double or triple the amount I'm using? The tank typically evaporates about 2.5-3g daily, right now I'm only replacing 1g of this with kalk, the rest with plain water.

Thanks!

[bertoni]

Those products should be fine for raising calcium and alkalinity. They can be added on the same day, but you'd need to be sure the first supplement was mixed well into the water before adding the second.

If the tank's pH permits it, more kalk should be fine.

[ACBlinky]

Great, thanks! I read/heard somewhere that it's not a good idea to use something like CaCl once you're using kalk regularly, as it reacts somehow and causes Ca to precipitate out of the water column. I trust your advice and I'm glad to hear I can use these two things as I've already got them in the cupboard. Once Ca and alk are back where they should be, I'll continue to drip kalk to keep them up.

Thanks again! :)

[bertoni]

Hmm, I use calcium chloride and kalk together regularly. :)

You're welcome!

[Billybeau1]

Yes, I'm not sure where you heard that but many of us use Kalk and Calcium chloride regularly.

I vote for increasing the kalk addition for awhile since you have the evaporation rate you have.

This adds a balanced calcium/alkalinity value to your aquarium and may be the best option at this point. :)

[Randy Holmes-Farley]

These articles may help:

How to Select a Calcium and Alkalinity Supplementation Scheme
http://www.advancedaquarist.com/issues/feb2003/chem.htm

Solving Calcium and Alkalinity Problems
http://www.advancedaquarist.com/issues/nov2002/chem.htm

The “How To” Guide to Reef Aquarium Chemistry for Beginners, Part 2: What Chemicals Must be Supplemented
http://reefkeeping.com/issues/2007-04/rhf/index.php

[ACBlinky]

Thank you all! I just wanted to post and say I was wrong (rather, whatever I read/was told was wrong or I remembered it incorrectly). I added CaCl one day, buffer the next, and have upped my kalk additions to finish raising and then maintain levels.

The only thing I can think of that's eating up the Ca this fast is the Halimeda macroalgae - it grows like crazy, and next to the fox coral it's the only really Ca-hungry thing in my tank (there aren't even many snails).

Thanks again to you all! :)

[bertoni]

Halimeda can consume enormous amounts of calcium and alkalinity, in my experience with it.

[Sk8r]

Also check your magnesium. It depletes more slowly, but once alk and cal fall during kalk dosing, that is often the problem. Get it up, dose to achieve the level you want for alk and cal, and the kalk will sustain it at that level.