you can make a jig for the front of you tank using sone thin mdf. Trace the top of the tank and cut with a jig saw. That way you get the same radius. Then cut two more out of mdf. This now gives you a mold to bend the wood to the correct radius and to clamp to while gluing up the hood. If you have a band saw you can cut 1/8" strpis of wood and laminate the curve easier than just bending 1/2" wood. Use a plastic resin glue and the water splash won't harm the joints and cause them to releas the layers.
Message to all aquariasts!!!!!
Anyone who lives within their means suffers from a lack of imagination.