I remember seeing a flapper in the output line when I set this up, but nothing to stop flow through the intake back into the canister. I like the fact that this has a single quick disconnect for maintenance, but will the intake line siphon down if I use the quick release before emptying the intake line, or is there anything in the quick release that will stop the water? Since the directions don't tell you a thing I figured I could ask here before trial and error. Do owners of this canister just usually pull the intake line out of the water to drain quickly, then unplug the unit? Then use the quick release to remove both lines from the canister? I just want to do the simplest easiest way.