I am contemplating making a wall with various caves and thru tunnels to put inside my FW
tank. I know there is lime in the concrete but once cured is it safe for the fish?
The dimensions would be 3' wide x 3' tall x 1 ' deep. I realize this will be quite a bit of weight, but I am hoping to make an eye pleasing display, and much of the weight would be lost by all the tunnels and caves.
Anyone with experience in concrete it would be appreciated if you replied.