I'm trying to find an inexpensive (<$40) light for a low light tank. The Tetra Half Moon is 18" x 13" x 20" so it's pretty tall. All I really want to keep is some anubias, crypts and difformis. Maybe some duckweed and pennywort. Due to the weird shape of the tank it kind of has to be a clamp on. I was looking at the wavepoint 6" but I can't find any PAR data on it at all. Any ideas?