We purchased our house last year and it came with a stock tank cowboy pool the previous owners had built, hooked up to an Intex 633T Krystal Clear cartridge pump. Its finally pool weather, so I refilled the pool almost to the top, since it was sitting just above the return jet. We went out of town for about two weeks, and managed to lose almost a foot of water in the interim.
Two things worth noting:

Two things worth noting:
- The timer on the pump is shot so while we were gone it ran constantly. I've tried plugging it into an outdoor timer, but the timer triggers the GFCI on the pump outlet every time it turns off. I'm planning on cutting off the GFCI on the pump and replacing it with a regular 3 prong since the outlet itself already has GFCI, which will allow the pump to work off the timer and run only 4 hours a day.
- The water seems to be coming out of this little air intake (see photo) I've found other threads with people facing similar issues. Is this something I can just seal up? Its hard to tell if it's coming out of the top, or if the tiny o-ring inside has failed. You can see the water dripping down the hose attachment, but it's also on the exterior wall, which makes me wonder if the exterior side of the return jet is also leaking?
