Re: CaCO3 problem

John Taylor [The Banshee] (s883351@minyos.xx.rmit.OZ.AU)
Fri, 15 Nov 91 13:02:43 +1100

>... Why not run an experiment: grow two sets of pings in pure perlite,
>water one set with distilled H20 (tends to be slightly acid), water the
>other with alkaline water. Unfortunately, alkaline tap water (like we
>have in AZ) may not be the best source of alkaline H20, as our water
>has pleanty of other stuff in it besides excess OH- ions! Still, it
>would be a great experiment to try, just to see if tap water could be
>used out here. I am not yet convinced that all Mex. pings like it
>alky, and I have too few of 'em to risk it myself!
MJC

What are the properties of Vermiculite? I know that it is spongy and formed
from the heat treatment of mica (?), but what about free ions, pH, etc. If
my memory's correct, I seem to remember that mica-like minerals can ion
exchange or something. Maybe it's not Ca 2+ at all, but something else it
replaces in the vermic. Mike's experiment idea is a good one, but I don't
have enough plants either, let alone any spare ones. You could also explore
pH effects using OH- and H+, as well as different substrates - how about
something more inert like agar or polystyrene foam beads/etc. to cut down the
number of variables a bit?