Mollygurl

can i use shale in my tank? i have some large/small pieces, and i wanted to put them in my tank for caves,decorations,etc.

sirdarksol

I'm not sure, but I wouldn't think so. Shale contains oil, which I would think would taint the water.

gmillar

Oil Shale has oil, yeah, but regular shale is just solidified mud. I would discourage using any sort of sedimentary rock, as it's liable to dissolve back into it's loose state in water, namely clay. Go with igneous (hardened lava) rocks like granite or basalt.