I’m going to be setting up a 40breeder 36” long and 18” wide. Wanting to get an ATI fixture for this. Being I’ve never ran t5’s before do I get a 36” long and 17” wide fixture or could I get away with using a 24” long fixture. I’ve seen pics of the fixture covering the whole tank and some not. What would you guys suggest?? Thanks just trying to do my research!