I've come to the realization that I'm not going to have enough time to DIY a canopy and lights. So I'm settling for T5 fixtures that I can lay flat on top of the glass lids of my 6ft long 180gal tank. The tank has 2 braces. If I get a pair of 36" long fixtures will the braces get in the way? Are three 24" fixtures a better way to go even though it will cost a little more? My general goals for this tank are to support low light plants, a big school of something yet to be determined, and very low maintenance.