Air bubbles from return

[d2mini]

If you look at the pic below, notice the last elbow on each return right before the loc-line. In the inside of the curve of the elbow (the side facing the water) I drilled a tiny hole to act as a siphon break in the even of a power loss. I drilled it underneath rather than on top so that any water leaking out of the hole would just drop into the tank. Well, the return on the left is spewing big air bubbles into the tank. If I cover the hole with a finger it stops. So it seems that as water flows through and past the hole it's picking up air. The return on the other side seems fine, no air bubbles entering the tank.
What should I do? Did I drill the siphon break hole in the wrong place? I could always plug it with a dab of silicon and drill another.

 

[ccCapt]

The hole should be below the waterline. Plug up that hole and drill a new 1 in the locline below the waterline.

 

[d2mini]

Thanks, will give it a try!

 

[SSalty]

The hole should be below the waterline. Plug up that hole and drill a new 1 in the locline below the waterline.

I could be wrong, but I don't think the hole should be below the water line. Wouldn't this cancel out the reasoning behind a siphon break? But I guess this will depend on how low the hole is, and how much room your sump has for excess water. On my manufactured all glass aquarium reef ready system, the hole is above the water line.

How big is your return pump. If the return pump is oversized, it could be the cause of microbubbles.

 

[d2mini]

Not micro bubbles... i said BIG bubbles. And it stops when i plug the hole with my finger.
I was assuming ccCapt meant just below the water line.
So ya, some would drain back to the sump but not enough to overflow it.

 

[cthegame]

I could be wrong, but I don't think the hole should be below the water line. Wouldn't this cancel out the reasoning behind a siphon break? But I guess this will depend on how low the hole is, and how much room your sump has for excess water. On my manufactured all glass aquarium reef ready system, the hole is above the water line.

Your not wrong but his suggestion was correct also. It does depend on how much room the sump has to handle the back siphon until the water level reaches the hole. So the higher the hole the safer IMO.

 

[yote]

The siphon break on my return is just above the water line.But I've seen just below too.So I think either way would be fine.