I won't to build a sump out of a 60 gal plexiglas tank. It fits perfect in the cabinet of my new 100 gal. The only problem is the 60 gal is to tall. It only gives me 6 inches to the top of the cabinet. I want to cut off 5 inches off the top of the pleat tank. Does any one think that's crazy? I think it will only have 30 gal of water in it because it is my sump. Does anyone know if it is safe to cut off the top of a tank?