Little Problem

[Kayak_Guy]

So I was testing my system for a power failure, and when I kill the power to the system, my return line and pump start to siphon water from the tank into the sump!

Any ideas on how to stop this?

[1F2FRFBF]

You need a check valve. You should be able to find it anywhere plumbing supplies are sold.

[Kayak_Guy]

<a href=showthread.php?s=&postid=10323358#post10323358 target=_blank>Originally posted</a> by 1F2FRFBF
You need a check valve. You should be able to find it anywhere plumbing supplies are sold.

Is that like a one-way valve?

[1F2FRFBF]

Yep. That's exactly what it is. Water goes in, but it can't come back out. :D

[AquaReeferMan]

Yes it only allows water to go up. Once the power goes out the weight from the water coming back down pushes it a little rubber piece down not allowing any water to move back down into the sump. It looks like this.(yes I know I need to empty my skimmer cup)

http://i42.photobucket.com/albums/e349/aquareeferman/125/checkvalve.jpg

[heyfredyourhat]

Check valves do fail, so i would not recomend them. Try drilling hole in return line to act as a siphon break.

[backyardspecial]

Forget the check valve, I hear they fail sooner or later. Here is a cheap way.

Drill a hole about an inch below your water line in the return pipe. When the power fails and water starts to siphon it will stop when it reaches the hole. Called a siphon break hole. Cost $0

[1F2FRFBF]

Drill a hole in the return line below the water line... makes sense, but I'm sitting here trying to figure out how to do that with my SCWD installation. How big would the hole have to be?

[backyardspecial]

What you should do is drill holes in both your return outlets so either one can stop the siphon. Holes don't need to be big at all. 1/4 inch should be good.

haha....nice avatar 1f2f

[Kayak_Guy]

So, drill it where? just below the waterline?

[george81]

yes you would drill a hole in the return line that is inside you re display tank, just below maybe 1" below the waterline. any size hole will do it is just to allow air to be sucked into the pipe to break the back siphon. I drilled mine with 1/4" i think.

[conefree]

Make sure you drill the holes on the back side of your plumbing, so if it gets uncovered, it is spraying the back of the tank under the trim, instead of up into the air and causing salt creep and/or spray into your lights.

[NirvanaFan]

or drill the hole kind of angling downward, so it sprays kind of down when the water level goes below the hole instead of up.

Also, make sure you test it to make sure the siphon breaks. I had to keep drilling bigger holes until the siphon finally broke, then I went with a bit that was one size bigger. It is probably around 1/4" or so.

[Kayak_Guy]

Thanks, will do!

[meco65]

The water level in the display tank should stay at the same level all the time. Or at least it dose in my tank. The hole I put just below the water line. The lower the hole is in the tank the more water will drane back into the display befor the siphon is broken.

[Kayak_Guy]

<a href=showthread.php?s=&postid=10334724#post10334724 target=_blank>Originally posted</a> by meco65
The water level in the display tank should stay at the same level all the time. Or at least it dose in my tank. The hole I put just below the water line. The lower the hole is in the tank the more water will drane back into the display befor the siphon is broken.

Right, so the higher the better, just so long is it's under the waterline becuase of the spray.

[george81]

yes and drill it all the way through the pipe both sides.

[Young Frankenstein]

<a href=showthread.php?s=&postid=10323456#post10323456 target=_blank>Originally posted</a> by heyfredyourhat
Check valves do fail, so i would not recomend them. Try drilling hole in return line to act as a siphon break. I second that motion, and also a check valve will add restriction to the line.

[Kayak_Guy]

Done! drilled just below the water line and it works fine.