I use a ProMax 80-20 bounce by Lumiquest. It velcros onto your flash all around the end. It has a storage wallet, difuser screen, white, gold, and silver reflector and the normal 20% forward bounce. When I use it I normally use the white insert with no difuser facing directly behind me so the flash bounces off the wall behind me and back into the tank. If the walls are a non-white however this can tint the color. I normally point it directly forward with the difuser attached and no insert so that only 20% bounces forward. 80 will bounce off ceiling and iluminate around the tank so that around the tank is the proper lighting as well as 20% getting into the tank that does not cause a glare. I will also use a polarizer filter at the same time to reduce the size of the glare to a clear sharp single spot rather than a large fuzzy area. It also has the benefit of darkening browns and greens in the tank. Vein structure will also be enhanced as well normally for extreme closeups.