"ClownPleco" wrote in message
oups.com...
Limestone will slowly disolve in an aquarium. Test you rocks by
dripping some vinegar on them. If you see fizzing, it's best not to
add the rock.

Limestone is perfectly safe if you have fish that like hard alkaline water.
I've been using it for years. It will also help prevent PH crashes. I
haven't had that happen since I keep these rocks in my tanks as decorations.
Some of my outdoor tank/pools have heavy loads of fish and the PH tends to
go down.


--
Koi-Lo.... frugal ponding since 1995...
Aquariums since 1952
My Pond & Aquarium Pages:
http://tinyurl.com/9do58
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