Jennifer is correct on the siphon, but if you don't vent the return you will have pressure/siphon issues and tuning the skimmer will be troublesome. It will never run consistently
Second that %100
Why would you disagree when you actually just gave the same answer as to how to fix it? (see below)Gotta disagree with you on this one. It's exactly how I have mine running. My skimmer empties into the first compartment in my sump which has a constant level. Due to the constant level there is a constant syphon, creating a constant vacuum, so it's not hard to get it consistent. I did it with the vent and without.
The only difference was I had to close the gate a little more without the vent, and it was MUCH more quiet without the vent.
Anyway, from the pics I still think it's not enough air, not enough flow, both or not enough poop in the water.
Gotta disagree with you on this one. It's exactly how I have mine running. My skimmer empties into the first compartment in my sump which has a constant level. Due to the constant level there is a constant syphon, creating a constant vacuum, so it's not hard to get it consistent. I did it with the vent and without. The only difference was I had to close the gate a little more without the vent, and it was MUCH more quiet without the vent.
Anyway, from the pics I still think it's not enough air, not enough flow, both or not enough poop in the water.
Eriks; Do you have a gate valve on the outlet. If so you may not need to replumb.