This is the canopy that I made for my 75 gallon, with the help of a friend, to match the stand that we made a few years earlier....the front doors seen above were later replaced with wood that matched the doors of the stand...
It opens at the top to allow gravel cleaning without having to remove the whole thing, and also has lift up front doors so that my short roommate can feed them. The fish in the smaller tank on the floor are my pond fish, overwintering in the house. (Their pond freezes solid, so they come in. Since this picture was taken, they have up-graded to a 100 gallon stock tank in the basement.)