So I have already replaced the faucet thing for a new one and it's still not siphoning. The aqueon that isIf your Aqueon has quit siphoning check to make sure it hasn't sucked up some debris and the pump is clogged.
You can unscrew the valve part at the bottom of the pump from the venturi at the top and get a look inside. Also remove the tubing and look in from that angle to.
For the Lee's changer that the OP is having problems with. There is a small black rubber O ring between the venturi needle and the main housing. It may be broken or missing. If you look down from the top you will see a hexagonal shaped indent in the top of the pump. Stick your thumb or something that fits the shape in there and turn that part counter clockwise while holding the pump body still to separate them. Once you separate the venturi funnel from the pump the O ring should be on the needle part. If you replace that needle O ring it should stop your leaking.
To stop the leak at the tubing, remove the tubing and cut the expanded flared end of the tubing off and then reattach. As the tubing stretches and ages it will develop a "memory" shape and it may leak.
Andy
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