75 Gal w 30 Gal Sump Reef(I told you guys Im back)

[bauder1986]

You know what. Screw it. Do it all. Check valve, reverse check valve, drilled hole, and make sure that the outlet is high enough that you do not flood your overflow. Proper way to be paranoid haha.

Well I did three of those things. I made sure that my overflow can handle a lot of water. And I've got the drilled hole. And lastly I change the nozzle into a 45 degree elbow that is only about an inch under water. It's actually handy that my overflow can't handle a lot of water back flowing into it. I only have maybe about 12 gallons in it and it's a 33-gallon sump. I would estimate that I get about 6 or 7 gallons flowing into the sump in the event of shutdown even if I plug the hole. Which is good because I need a bout 10 gallons of water in the sump to pump back into the tank to restart siphon on the hang on back overflow. And that's roughly what I get before the pump is sucking air into the tank.