python or python like device like footballfan posted is best. it can drain and fill the tank.
Someone else set up my tank as a gift for my 5 year old. Is there a device I can buy to pull the old water out easily. My tank is a 37 gallon.
like petluvr said. its part of the filtration system. both ends of the tank there is a square box with slits. as water is pumped into the tank it fills