Ready to jump from halogens to LEDs. I could use some objective advice. Tank is FOWLR, 5 feet deep, 10 feet long 4'front to back(1500 g). Concerned about getting decent light to bottom. Stores that carry these brands assure me they will do the trick. Don't entirely trust their motives. How many would I need to give the tanks proper lighting given above dimensions? Would love to hear from anyone with experience with these brands. Thanks...