I don't think this would bve advisable. One problem is that the lack of the security sensor is an obvious risk but their is alos a technical issue, the pump runs for about 10-15 seconds after a fill is detected, this is to minimize off and on cycling and on such a small tank that would be enough to cause an overflow. The optic sensor is about 1/2" around and 1" tall and the float is about 1" around and 1" tall.