Too much

[Holyreefer]

Why do some people dose Randy's 2 part (really 3) and Kalk if the recipes help maintain Ca & ALK?

[Randy Holmes-Farley]

Either they do not want to set up a limewater delivery system, the pH gets too high, or it cannot keep up with the demand in the tank (or they have some more esoteric reason for not wanting it, which I do not understand, like the zeovit folks being against it). Also, the two part eliminates most concerns about magnesium, where limewater does not. :)

I compare various methods here:

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

[Holyreefer]

Thanks even though i have been dealing with saltwater tanks for a while now. The chemistry is still every interested!

Its funny because i've noticed that you can get all the same results with so many different options.

[Randy Holmes-Farley]

Oops, I think I misunderstood the question. I thought you were asking one vs the other. Both together would be a good choice if limewater alone is not potent enough even when replacing all evaporated water, and the limewater has a bigger pH raising effect if that is needed. :)