drill holes in return line?

[Reverend Reefer]

what do people mean when they say they drill holes in the return line to the display from the sump? they say it has to do with breaking the siphon. what does this mean? where do i drill the holes? near the return pump or at the top as it goes over into the display? if i drill holes on the pipe going back up to the DT, won't water come out of the pipe via the holes?

 

[JBrown]

Your going to want to drill a hole just above the water line so in the event of a power outage your return line does not create a siphon draining your tank in the process

 

[Jocephus]

When the power goes out, the lowest pipe in your tank is where the water will drain to. Until it sucks air, water continues down into your sump and if your sump is small, onto your floor. When people advocate drilling holes in return lines what they are trying to do is to break the natural syphon that happens when you lose power. The holes should be drilled just below the rim of the tank ON THE INSIDE. If you drill the lines before the water would spill into the tank, the water will shoot all over. Make sure the holes will only squirt water into the tank. Make sense?

Good luck!

Joe

 

[KafudaFish]

The hole is very small like 1/16" diameter so very little water flows out. Some people put two in that way if one is blocked with say a snail the other will allow air in breaking the siphon. It is just like when you put your finger over a straw end and lift out liquid. Remove the finger, air enters and liquid flows.

So how do you know if you need one? If your sump can handle all the water that returns when the power is off then no. If it would overflow then yes.

I have also seen people with them below the water line. A gallon or a few may sipon back but once the hole is exposed to the air it breaks.

 

[zoolan70]

I just drilled two 1/16" holes into the "bottom" of the elbow where the return line transitions from vertical (up through the overflow) to horizontal (Loc-line). I also have my return lines spraying right at the water's surface, just in case.

 

[Drjusc00]

Good idea!!