OK I HAVE A 30g SUMP THE WATER ON MY RETURN PUMP CHAMBER IS EVAPORATING TOO QUICKLY I NEED TO ADD WATER EVERY COUPLE OF HOURS I JUST CHANGED FROM A 20g SUMP TO A 30 I DID NOT ADJUST THE VALVE THATS RIGHT OVER THE RETURN PUMP COULD IT BE THAT I SHOULD CLOSE THE VALVE A LITTLE MAYBE SLOW TO RATE OF THE WATER GOING IN THE TANK...IDK ITS JUST A GUESS...