HElP, back siphoning, how to stop it?

[coryjac0b]

ok, so i setup my first system with a sump, it is a 200g oceanic tank. 84x24x25, It has 2 overflows in each corner, it is outfitted with holes that fit a 1"inch bulkhead. The plumbing for the return is a 1 inch line that tees off to 2 3/4" lines. the return hangs over the side. i have the pipe coming up to a 90 then a street ell so it makes a u shape, then another 90.


i'm using the panworld 50-px-x for a return. i plugged it in, and it seemed it was filling the tank faster than it could drain, so i unplugged
it. then some back siphoning happend.



Now i know the reason why it back siphoned so much is cuz the white 90 is so far down, but it's only there temporarily until my loc-line i ordered comes in, what can i do to successfully stop the back siphon after the loc-line is in?

 

[USC-fan]

drill a holevin the pipe just above the water line.

 

[Gundo5000]

<a href=showthread.php?s=&postid=9344650#post9344650 target=_blank>Originally posted</a> by Kb-smoker
drill a holevin the pipe just above the water line.

Exactly, but youll need a hole in each return since you have two. A small hole is fine.

 

[coryjac0b]

should this hole be cleaned often to prevent clogging? and what size like a 1/4" or smaller?

 

[USC-fan]

Yes clean it alot. The smaller the hole the more likely it will clog.

 

[Scooter12ga]

I drilled two holes on each return. The holes are about 3/16" in diam and each return has the holes staggered a bit. The first hole is about 1/16-1/8" below the water line (to prevent bubbles created from splashing) and the second hole is on the opposite side of the pipe about 1/4" lower than the first hole. - Can't have too much redundancy right?

Here's my hypothesis - The lower hole should be less likely to clog from calcium et.all... since it never has the chance to contact air. And keeping the holes on opposite sides should prevent something like a snail from covering both holes.

Let's hope my hypothsis never needs to be tested.

I tend to do my water changes from the sump and frequently unplug the return pump during this process. I hope that if there ever is a clog that I will notice it during a water change and can immediately plug in the return pump again.