I've attempted to clean my boyfriend's fish tank (he is overseas) and I cannot regain suction on the canister filter he has. It is set up so that the intake is pvc piping which runs down to the canister and connects by tubing. The outtake tubing also runs to pvc from the canister which runs along the length of the tank and has holes so that it trickles down.
There is some water being drawn up the outtake as a little is trickling out the top but suction is not as it should be. The majority of the out hose is an air pocket and there is an air pocket in the intake too... Please help.. the tank looks worse than before now and i don't want to kill his fish!
i've been at this for hours and i'm going to give up soon without help.