What is the size of the air tube? If to small compared to the main pipe could be it does not suck in enough air to break the siphon. Is there any way a wasp nest could have plug the air vent? Run water threw it if you can.

61 acre water shed lake. bass, channel cat, black crappie, wiper, walleye, redear sunfish, blue catfish and bluegill. To many bullhead and common carp
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