I have riccia in my 10g, I replaced the stock bulbs that I got with hood with 2 10watt fluorescent bulbs. Riccia growing well. I used flat pebbles, put the riccia on it, then covered it with a nylon mesh. and tied the bottom side of the mesh with fishing line, then just spread the riccia rocks in the tank, been about 2 weeks now and only a little bit of the mesh is still visible. The mesh by the way I bought for a dollar at dollar store, was part of a laundry bag.