Re: rocks

["S. Hieber" <shieber at yahoo_com>]

Richard J. Sexton said, in part, about cement in aquaria:

> You'd need to leech it with hyrdrochloric acid
> (outdoors!) of course to
> reduece the alakalinity.

If you're talking about any of the forms of portland
cement, it is indeed alkaline and the only way to eliminate
tha akalinity is to remove the cememnt entirley.  Acid will
do that.

It's like trying to reduce the alkalinity of  Calcium
Carbonante.

An early acid soak can remove the "freer" carbonates that
might have been in the mix and which would otherwise more
rapidly leech, but portland cement will always be alkaline
and will always decay under exposure to acids.

It's one reason why the rain makes the aggregate stones
show through on the sidewalk in front of your house.

Portland Cememnt works best if sealed or used where
alkaline water is appreciated.

Scott H.

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