Use a straight-cut bit. Clamp a straight-edge to the tank (a large aluminum level works well, but a straight board would be fine). Take your time and carefully reposition the straight-edge for each cut.Unless I buy a CNC soon, I think a router and guides the most accurate tool I can use
From the picture the acrylic does not appear to be an inch thick. An inch sounds a bit heavy even for a tank 72" long and 24" high. If it were me, I would use a circular saw with a blade for cutting plastics. Just tape off the area where you want to cut, clamp a rail in place to keep everything nice and straight and cut away. You can pick up the blades at Lowe's for about $8.
I thought the same thing, are you sure it is 1"? Most tanks that size are made out of 1/2", my 96x24x30 is made out of 3/4", but it is thicker than a lot of similar-sized tanks.From the picture the acrylic does not appear to be an inch thick. An inch sounds a bit heavy even for a tank 72" long and 24" high. If it were me, I would use a circular saw with a blade for cutting plastics. Just tape off the area where you want to cut, clamp a rail in place to keep everything nice and straight and cut away. You can pick up the blades at Lowe's for about $8.