Sump

[adampw]

I am ready to start setting up the plumbing for the sump I just built. I had a question about getting the water from the Main to the sump. I know a lot of people use overflows but there is always that little unknown in the back of your head of the event of a power failure then a flood. Could a person just use a small 300gph pump to get the water to the sump? In my mind, if you did this and there was a power failure no water woulf flood from the sump or the main display. If the pump in the sump failed the worst that would happen is that the water in the main tank would go into the sump until the water line was low enough to where the pump in the main would have no water to pump. Would this work or woul it be better to just use a overflow? If so, what overflow would you recommend? Thanks!

[reeffreak]

No,a pump will not work.There will still be a siphon going on even when the electricity goes out.Water will still continue to drain as long as the intake is still under water.

You have two options,either drilling the tank(someone else will need to help you on where and how to do it) or an overflow box.The Lifereef overflows are the best on the market,IMO.There are others that maybe good too like the CPR with the qualifter pump.

[yote]

When set up right,an overflow wont flood your floor when the electricity goes out.You will have to make sure that the return pipes either have a small hole in the bottom,or the ends right at the water surface.

[Bifferwine]

Yote and Freak are right. Using a pump will not work. You'd have to perfectly synchronize it and your return pump (which is impossible) or else you will have a flood in either the main tank or sump. Using a pump is a surefire way to get a flood.

Tons of people have sumps. We either use an overflow box or a drilled tank. If there was such a big risk of a flood from using either of these two methods, people wouldn't do it. But there isn't. I've used an overflow box from CPR on my old tank, and it worked great. I currently have a drilled tank, and no floods here either. Whichever way you decide, you can test your confidence by unplugging your equipment while you're at home and seeing first hand how it works, and it will show you that it won't flood.

The principle of an overflow box is that the lip of it is somewhat below the water level. The return pump is moving water from the sump to the main tank and pushing the water over that lip, back down to the sump. When the return pump shuts off in a power failure, the water level no longer reaches the lip, and water doesn't go down the sump anymore. The overflow box can only drain as much water as the return pump is pumping, so if the power goes out, the return pump goes off, the overflow box no longer moves water either.

Like Yote said, you either need to drill anti siphone holes in each return line to stop a reverse siphon for happening, or plumb your return line with a one way valve (which is what I did).