Originally Posted by eviltrain

the inlet of the overflow covered with sponge lor. then the outlet of the overflow to the bottom. oh ya, 1 thing to take note is your canister must be able to pump water from bottom tank to top tank without problem. that is to say, the 2nd tank water height must be higher than the canister itself. the canister should have headMAX of at least 1.8metres to provide enough strength.