The 20 gal long has just about the right size panels for lids on a host of tank sizes, provided you glue new lid guides into the center brace to size these panels so they can fit anything from 210 to 50 gallon tanks. Here are some pics of the basic procedure and end result. You'll notice the use of a feeler gauge to cut between the tight (almost no gap) side panels once you have a razor cut started into the ends. Because these tanks use trim that serve as jig-frames they are very ridged and cutting the corners really helps, followed by a heat gun to soften makes peeling them off easy. Without the frame you have a rimless tank or needed glass panel lids normally costing more than twice as much as the tank so it well worth it to me, last pic shows a side to side sliding lid configuration and the new guide glued onto the center brace. 8^D
