FeliciaLynn
Guest
I was thinking of drilling a hole in the return as well. Figured I might as well have multiple safety mechanisms in case one of them fails. The check valve is best because it allows no back siphon, but then in case that fails a siphon break hole would only let a couple gallons of water go down into the sump before the hole was exposed and the siphon breaks.How do you plan on setting up your return? You can possibly do without the check valve if you use Loc-Line and then drill a really small hole on the underside of one of the connecting pieces, typically closest to the glass so that when the return pump is turned off, some water will back siphon but not enough to be a problem. It really depends on the height of the return line in comparison to the water line based on the positioning of your overflow.
The return is going to be a single 3/4" lockline with a flared nozzle. I positioned the bulkhead as close to the top of the tank as possible because I want the return to be close to the surface for surface agitation.