DARB

I have molds of all sorts of rock cliffs and rocks. I Use them for some waterfalls and ponds ect.. I would like to mold some for my tank. But would that mess up pH levels and the akli in conceret do any thing. Plus color stain pigments play a fackter..

Steen16

concrete xcan contain lime witch is not very nice for fishies

DARB

I plan to use stright portland and crushed seashell and no lime additive. It looks like coral. Have you ever herd of this in fish tanks. It works in live ponds and zoo tanks. But a 50 gal.....

Steen16

quite ansure myself sorry but some1 els is bound to help