Re: Aquatic Plants Digest V2 #236

On Fri, 4 Oct 1996 03:39:02 -0400, Aquatic-Plants-Owner at ActWin_com

>Suppose a particular soil or clay has a lot of magnesium or calcium compounds
>such as from dolomite or limestone, is this a cause for concern as a substrate?
>Folks have often mentioned problems with rising pH due to seashells or limestone
>in their substrate. Is this really a concern for plants? or fish? Can this
>be balanced by the use of peat or other sources of humic acids?

MY guess is that this would only have an effect (if even a noticeable
one, with such a small quantity) in the very short term.  Marine and
african cichlid tank keepers who are using a substrate/rocks  entirely
composed of dolomite/coral/limstone find that these become coated and
lose their pH buffering capacity within months, and with the small
amount you're speaking of and mixed in with soil, I would imagine this
would happen even faster and have a smaller effect in the interim...
But then, someone else may have a different experience.. :)