it is doubtful this would take the weight of a fully filled tank, especially due to the height of the unit. any imbalance in load, or floor surface will cause the full weight to be transfered on the horizontal plane causing sheering force at joints. Best put a back and sides on the unit, although not load baring doors would allow the concealment of external pumps and fish paraphernalia. addition of central strut along the length of the top, surcured to the (3/4 ply possibily) sides will assist in taking the load.