shale

[swank]

I think its called slate rock, its black, fairly thin 1/2 inch, smooth, all black, comes in different pieces and easy to break with hammer. Has anyone used this before in a discus tank? Does this type of rock raise the ph? thanks

[Jhhnn]

I think you mean "slate", which is metamorphosed shale. It's widely used in aquariums, also as flooring and roofing. Composition will vary depending on the origin, so it's best to put some in a large bucket of water for a few days, then test the water to see what's what...

[underwaterforest]

Good thing it is slate not shale, if my high school geology serves me, shale is basically just highly compressed mud. You need the heat of fusing the grains of sand from metamorphosis to keep it from breaking up in your tank. I have used local slate in my plant tank and haven't noticed any pH change.

[swank]

Its been long week ..Just couldnt think of the word slate..LOL
shale geeez Im such a dork..