I was orginally running 1 36 watt turbo twist on this tank however I do not believe I am getting enough out of it for this body of water. Rather than going with a larger unit I and thinking of adding another 36 watt turbo twist running in Tandem about a foot higher than the other and upgrading the pump to about 900 gph for the both. Does anybody see any issues in doing it this way? Does doubling the UVs do the same as adding a larger one?