Kalkwasser

[Nemo]

what is this all about? Is or does aragonitic sand accomplish the same results?

[phistio]

not quite sure if i understand? are you saying that argonite sand establishes ongoing levels of calcium? if that's what you're asking then the answer is no...

kalkwasser (german for lime water) is a very long lived practice of adding calcium to a reef...kalkwasser (calcium hydroxide) has never been equaled for calcium addition to a reef. there are many substitutions (i.e bionics) that come close, but are often two part systems, which isomers are bond with a substance, that in the end remains in your tank after the calcium has been depleted...

the problem is (most reefers find) it requires more work, and cannot be added to a tank in a short amount of time...it must be added drip by drip over the course of hours, if not days...(i'm dosing as we speak...it will take 2-3 days to empty a half gallon solution of kalkwasser.)

[Nemo]

the calcium is for the corals right?

[phistio]

correct...coral skeletons use calcium, as well do snails, pink, purple and green calcarerous algaes all benefit from calcium...

aragonite, on the other hand, is a naturally occurring biogenic (life formed) mineral that reaches equilibrium with sea water at a pH of 8.2. It also automatically dissolves into its primary components of calcium, carbonate, and strontium when the pH falls below 8.2 (the natural pH of sea water) thereby driving the pH back towards 8.2 with a slight excess of strontium ions.

[Nemo]

If I was to add some aragonite to my tank now would I need to be cautious of how much I put in etc.

[phistio]

not in my opinion...it's not as caustic as kalkwasser...however, the calcium will deplete, and must be maintained!

[Nemo]

Would you say that it is a good idea for a reef aquarium with fish and other invertibrates to periodically add some calcium into the system?

[phistio]

fish, and some inverts don't really utilize the calcium...some invert might use the calcium for skeletal growth (i.e. hard shelled inverts, tubeworms, feather dusters, snail, etc.)...but the supplemental calcium more helps the rocks and corals. so, in answer to your question, in say a FO tank...IMO fish would not benefit much from the calcium...however in a FOWLR tank, the live rock might benefit from the kalkwasser, or calcium.

[Brad]

I have also herd from my lfs that Kaulkwasser also helps reduce the amount of algea growth is that true?

[HoopsGuru]

Instead of just adding it in case you need it, I would suggest buying a quality test for it and then dosing if you feel it is required.

I agree with Phistio's statements that in your case the Kalk probably wouldn't be a necessity and is really more of a "professional" approach for reef keepers. IMO, it could be much more of a hassle or danger than a big help.

As far as algae is concerned, I would look more for the source of the problem than adding a supplement to take it away. Algae, depending on the type, has different fuels that help it grow....perhaps you can give more info if you are having an algae problem and we can eradicate the source!