> Most people you talk to recommend shell grit to supply calcium to young fry.
> What are your (anybody) thoughts on using another source, like kalkwasser.
> I have some left over from my reef endeavors and thought I might be able to
> put it to use. I'm wondering if the calcium in the CaOH would even be
> available at the pH at which we raise rainbows. I"m interested to hear
> comments, as well as other suggestions.
Mike there is a major problem with Kalwasser as a calcium addition in
this case. It is a sparinlgy soluble form of Calcium hydroxide and would
raise the pH of your water rather considerably.
It would be possible to add gypsum, which is predominantly CaSO4 for
simple calcium addition. Mail order you may be able to get the chloride
form from a hydroponics shop.
However we still have not really sorted out whether or not it is the
Calcium that is important or whether is it the additional buffering
supplied by the Carbonate. Shell grit is pretty easy to get a hold of and
not so hard to use and so it is probably just as easy to get some of that
and use it.
Peter Hughes