Luckily I’m just water testing though it went bad the first time my overflow keeps flushing, it fills up and then drains causing a loud gurgling and I’m not sure how to fix it. My main siphon is currently just a bulkhead hole that the water goes down but I’m not sure how to fix this. I’ve tried filling the tank up a lot but that just fills my sump up to much, I’ve increased and decreased my return pump flow, I’ve also slowly closed the main siphon with a valve to see if that helps but it’s still doing it. Is there a special plumbing I’m supposed to use? Would love any ideas and fixes!