Will this cause a Backsiphon issue?

If I run my retun pump back into the main tank from a sump below, and I use PVC pipe, and I run the return almost to the bottom of the tank behind the live rock. ......If I lose power, will all my water siphon out?
I wanted to end the return pipes down low and behind the rock to create flow where I would not be able to place and/or retrieve a power head from. Any opinions on this and whether it is a reasonable idea or not?

 

Yes it will siphon.  Drill a small hole on the inside of the PVC above the water line.  Water will dribble into your tank from the hole, but if you lose power the air will break the siphon thus averting disaster! A 1/16" drill bit will do the trick.

 

Thanks again Craig! You are quick on the draw....or should I say keyboard.. ;D
Is it a dumb idea to run the plumbing that low in the tank or does it make sense....If I do it, I will drill that hole. Hubby picked up on that one. What a disaster that could be!!!
Empty Tank, Soggy Floor! [smiley=bigcry.gif]

 

Drill the hole above the water line!

 

Hey Craig, I need some help

I have tried for an hour to drill a hole on the inside of the PVC pipe but the drill just will not fit inside that pipe. So what is the trick

You can also get a check valve

 

Get a pin and heat it up. Use it to create a pilot hole for the drill bit. You can also heat the drill bit itself, but the pilot hole worked better for me.

 

Craig that went over your head [smiley=bouncylaugh.gif] Go back and reread it, there was some humor there for you.   the** drill** won't fit **inside** the pipe  

 

Duh, too early in the AM Boomer!

 

Great! Hubby had asked about check valves for PVC pipe...so thanks Boomer...you must be psychic! :

Thanks to both of you.....!...Got it ABOVE the waterline for hole.....

 

Yup!