I'm going to purchase one of these units and mount it under my canopy. I have a 72x18x26 acrylic tank I have about 4" of clearance under my canopy with 2 4" fans at each end 1 in and 1 out. I can raise the canopy another 1/2' without to much hassle. My question is will this be enough air flow under the canopy to keep things cool the light unit is 2.75' in height will this be to close to my acrylic tank top and will it melt the top of my tank?