[Starry]

It's a small canister that connects to the airline going to the venturi intake. Just connect another foot or so of tubing to where the air is taken in and it shuts it right up. The css can be run HOB or in sump. Mines set up HOB for now till I get my 25 gallon sump set up. I dont like the Rio water pump in my tank, its too big and bulky. But wont matter in a sump application. I have mine running fairly dry so as not to tempt it to over flow. I think the wetter you ran it (water level higher) the more likely of a flood. I have my pump intake about 1" below the surface so if it DOES flood, Im not gonna loose alot of water.