Another rookie mistake. Always put the tank on something designed for and dedicated to that purpose and nothing else. If you have it on a table, desk, or dresser then anything else you are doing with it (like opening and closing drawers or putting something on the table) can stress the fish. Plus, it might not be designed to hold that kind of weight for a long period of time. And whatever material it's made of could become water damaged, possibly to the point of affecting its structural integrity.