I have a 2 x 39w T5HO (36") light above my tank. I seems a little dim at the substrate level as the tank is 21" deep. I would like to add one additional single 36" HO fixture along side my exsisting one. Does anyone know where I can find such a light? I could just purchase another double fixture like I have, but I don't want to end up with too much light.
First a few of quick questions, is you light suspended above the tank or level with the top rim? What spectrum (K) are the bulbs? When was the last time the bulbs were changed?
In theory, two T5HO bulbs with good reflectors over a 21" tall tank should be medium/high light.