Return plumbing preventing a reverse siphon

[serpentine5]

ok, How do i keep my return from my sump from doing a reverse siphon in a power outage? I am plumbed with 3/4 PVC and pumped by a Mag 9.5. There is a ball valve after the Mag and before the display. Also, my current overflow is sitting deep in my display and it has extra holes drilled into it to allow enough flow into it to stop the system from sucking air. How can I prevent it from draining half my display in a power outage? I hope I dont have a power outage or a pump failure anytime soon! Thanks all.

[RicksReefs]

for your return pipe, just drill a small hole in it at
the water level.when power goes out, the hole will
suck air, breaking siphon.
just be sure to check it on occasion for blockage.
HTH

[krish]

Hi,
I am just back after messing with my
tank.
I have a Iwaki 40RLT plumbed via
1.5" pipes. The Pipes split to 2 returns
via a "Y" union. Now here is what i
saw.
I had 2 returns submerged. The back
siphon happened right after the pump
was powered down.

I had one return submerged, while the
other open in the air. The return
that was submerged was the straight
and shorter part of the "Y" piping.
Even though the longer circuit was open
to the air, the siphon action still happened with the one return.

Now the solution is
a) Drill multiple holes just above the water line and also below the water
line on both returns.
Coraline growth and salt creep will
definitely clog the holes.
b) Definitely add a check valve. It is
a requirement. At least i feel so.

-krish

[clamster]

You could push an air tube into that hole... just make sure the other end of the air tube is fastened to the inside of a canopy away from water surface.

[krish]

True,
Thought about that as well. Will try that out.
I am going to have the holes drilled and in addition, will stick in
the tube.

tnx
krish

[serpentine5]

How do you keep it from spitting out water from the hole I drill? The water pressure is pretty high in the pipe, if I poke a hole in the pipe it would just squirt out.

[krish]

It will squirt water.
I plan on drilling the hole at an angle just a little above the water
level and facing the back wall of the tank. Also a couple of holes under the water level.

I also plan on inserting the airline tubing.

If the water squirting is an issue, then the airline tubing and
a check valve would be the viable options.

-krish

[Wind]

looking for pics of return.. thanks..

[krish]

Alright,
I will try to get some pics up.
I did mess with the holes a couple of days ago.
I made the holes bigger. I stuck in an airline tubing. The
airline tubing will help to make sure that the hole will not
get clogged. You could move it a bit and loosen stuff. But
in reality, the airline tubing is introducing air bubbles into
my return due to the venturi effect.
But the holes are working great in my setup. I drilled about
4 holes on each of my 1.5" return.

-krish