I have a breeding pair of RTMs in a 90 and I use pool filter sand 50lbs $9.00 mixed with a 5lb bag of black sand. I also use a black background. For lighting I have a 30" double fixture with one atnic and one 50/50 bulb. Decorations are a tangel of driftwood on one side with a flat rock underneath they spawn on. They will move things around to suit their needs. It's a very cool look.