Been thinking about rocks a lot lately. When I searched hypertufa, I found this old bit. Has anyone been trying it that can give us firm answers?? With the craze for holey rock, it seems a workable manmade rock would be a winner. I've done the hypertufa bit for a number of garden items but never put them in a tank. Changing hobbies and changing"needs" you know. Seems on the surface that one could work out a recipe that would fit the bill. As mentioned peat isn't required. Any concrete is just a mix of cement, small aggregate( sand) and large aggregate (rock) to do provide whatever strength is needed. If one built hypertufa in a block and placed styro blocks to later form tunnels through the rock, could he not make a quite nice holey rock? Seems to be quite a lot quicker and easier than hunting cheap holey. At least if you are doing it on the back patio, you know where to find it. Cement, sand, and ground up white beadboard should give enough strength without too much weight.
You try it, guys. I'll be over here watching. :zz: