How to stop back flow.

[trouble93]

I'm looking for some ideas for a safety measure in case of power outage if I'm not home. Right now if I lose power my return pump start to back siphon. I use to have the pvc return pipe about 2" under the water line so as soon as air hit it it would stop the siphon. I had to add some more pvc so I don't have that as a stop gap anymore. Is there a one way valve I can add that would not let water go backwards? By the way it's all 3/4" cpvc.

 

[scopus tang]

Originally Posted by trouble93
http:///forum/post/3208268
I'm looking for some ideas for a safety measure in case of power outage if I'm not home. Right now if I lose power my return pump start to back siphon. I use to have the pvc return pipe about 2" under the water line so as soon as air hit it it would stop the siphon. I had to add some more pvc so I don't have that as a stop gap anymore. Is there a one way valve I can add that would not let water go backwards? By the way it's all 3/4" cpvc.
I believe they make what is called a "check valve" for this exact purpose.

 

[trouble93]

Originally Posted by Scopus Tang
http:///forum/post/3208290
I believe they make what is called a "check valve" for this exact purpose.
Thanks I've seen check valves for like air line tubing just didn't know if they made one for 3/4" pipe.

 

[chrisnif]

The best thing to do is drill a small (like 1/8") hole just below the water line, and then another one like 1/4" below that. I actually have mine with a series of 4 holes and it loses siphon once the first is fully in the air, but I prefer safe to flooded (never know when a snail might get on the hole, or if it clogs with coraline). A little bit of water does come out, but not much, and the near surface hole gives me good agitation and makes the water shimmer (I have MH lights).
Hope it works out for you.

 

[trouble93]

Originally Posted by Chrisnif
http:///forum/post/3208310
The best thing to do is drill a small (like 1/8") hole just below the water line, and then another one like 1/4" below that. I actually have mine with a series of 4 holes and it loses siphon once the first is fully in the air, but I prefer safe to flooded (never know when a snail might get on the hole, or if it clogs with coraline). A little bit of water does come out, but not much, and the near surface hole gives me good agitation and makes the water shimmer (I have MH lights).
Hope it works out for you.
That's a good idea but that wouldn't work for me...I have waves that rock the surface water about 2 to 2 1/2" from side to side and it wouldn't be long before those holes would be covered with coralline.