Anti Siphon Holes....

[Reefer2727]

Wondering where to drill these holes on my return lines which go over the back of my tank and into each corner? I have heard some people drill them just below the water line and some just below?

Any pics would be totally helpful. Also, what size holes?

Thanks

 

[woodiecrafts]

I drill mine a 1/4" below the water line with a 1/4" hole on each side of the pipe. That way if one side gets blocked, you still have the one on the other side to break the siphon.

 

[bassnredneck]

Drilling them just below will keep them from spraying water when the pump is running. A quarter inch hole is plenty big enough, just watch that it doesn't get stopped up with algae or etc.

 

[Reefer2727]

1/4" under the water line. Now will the tank drain that 1/4" before the siphon breaks or can this happen before the actual tank level hit the siphon height?

 

[Imzadi]

air has to go in the hole to break the siphon, like a vent.

 

[OwenInAZ]

As a secondary backup, because more than likely your holes will get clogged up at some point, it's a good idea IMO to make sure the end of the nozzle itself is sufficiently high in the water to break the siphon. Make sure your sump can hold all of the backflow, and BAM no sleepless nights (or a need for a shamwow!)

 

[Toddrtrex]

Going off of what Owen said....

I don't trust anti-siphon holes. I just make sure that the end of my return lines are high enough (( and my sump has enough room )) to break siphon before any flooding happens.

 

[jb61264]

Mine are only probably 1/8" below the water line...I drilled a 1/8" hole straight through the pipe (both sides of each return). In my case what Toddrtrex holds true as well because my sump is 55 gallons and can actually handle the additional backflow if for some reason the anti-siphons do not work...fortunately, I've never had that happen before.