I have a new tank on the way. It will be 60x18x25 so I will have a 60x18 base to hold my substrate. This will be my second tank, the first is a low tech 50 planted tank. The new tank will also be a low tech planted. I'd like black substrate and I would like a course material. My current tank has a planting mix from aquariumplants.com which is doing what it is supposed to do. But my current substrate is brown which I don't like and it is very fine and hard to keep clean.