I've heard the word TexBlast used for a substrate? What's the who, what, where, why, when, and how of it? I live in dry Utah were everything from the earth has a 7.8 pH buffering capacity, including the gravel from local gravel yards. If you could help me find of source of gravel that doesn't buffer the pH up, my Discus would be greatly pleased. Matt VanBuskirk j.vanbuskirk at m_cc.utah.edu