Central overflow question

[jgruvey]

I’ve got a herbie style overflow with an elbow on the main drain for sound. It’s about 6 inches below my emergency standpipe in the drilled overflow. My issue is that I’m getting air bubbles in my siphon so my apex auto feed setup is running my return pump dry when it restarts when I feed. Do I need to lower the main drain standpipe lower to add more water volume and force the siphon to push through the air bubble or does anyone have any other suggestions?

 

[lapin]

If the drain pipe has a 90 somehwere in the middle it can cause air to be trapped
If the drain pipe is too far below the surface in the sump it can trap air

 

[jgruvey]

If the drain pipe has a 90 somehwere in the middle it can cause air to be trapped
If the drain pipe is too far below the surface in the sump it can trap air

Drain Pipe is a hose, I would say that it moves laterally and is not fully downhill the entire time but not by a lot.
It's halfway down in the sump. Should I cut it shorter?
Any other suggestions? I've been tinkering with it for a while. Cutting the standpipe got me to where it restarts the siphon most of the time but not 100% of the time which is what I'm hoping for if that's even possible lol.

 

[lapin]

1/2 inch under water is what I do. My pipe is a straight shot down to the sump thru a gate valve

 

[jgruvey]

1/2 inch under water is what I do. My pipe is a straight shot down to the sump thru a gate valve

That doesn't create a bunch of splash noise only putting it 1/2 inch under water?

 

[jgruvey]

I'll cut it if I need to but it's all glued so I can't go back after I do so it makes me nervous.

 

[jgruvey]

You were right thank you. Siphon is starting every time now with no issues. Appreciate your help! I will now have to dial in flow again but that helped a ton been fighting with it for days.