Pump seems to be losing prime while on

[User2342]

I have a 1hp jet pump that is pumping up from a shallow well. The well is about 20ft deep and water ranges from 5-10ft down. I have a foot valve at the bottom of the suction pipe and a check valve above ground in front of the pump. Discharge side goes to irrigation system and pressure tank.

I am having an issue with the pump only pulling water for a few seconds and then it goes away. If I wait 20-30 more seconds it comes back. I made a video that can be seen here:

 

[Banjo Bud]

Looks to me like your either running out of water or else you pump is starting to fail. If you’re running out of water, is your foot valve deep enough? Can you see water in the casing above the foot valve? I don’t think it’s a prime problem.

 

[Sponsor]

 

[User2342]

The foot valve is about 16ft down (about 2ft above bottom of well) with the water line about 5ft down.

When you say running out of water, do you mean that my pump is pulling water out of the well faster than it can replace itself? If that's the case, is my best option a smaller pump?

 

[Valveman]

If you can see down the well check the water level when this is happening.

 

[User2342]

I can't, but I have a cap on the side of the casing. When I removed that I can hear it sucking air right before I lose the water so I think I must be over drawing my well. The top of the casing where the suction pipe comes out isn't air tight. If I seal that, would the low pressure that will develop in the casing help draw water out of the ground more rapidly?

I have a ball valve on the discharge side that I can choke down and get continuous water around 8-10GPM, but it has to be almost completely closed so it is hard to narrow in on. I am thinking of downgrading my pump with the thought that saving electricity from 1hp to 1/2hp will pay for itself over a couple years. The other options I'm considering would be a dole valve or a pool diverter valve that lets me more accurately chock the flow. Any thoughts on which direction I should go?

Thanks for all the help.

 

[WorthFlorida]

On first start of the pump after it has not been used for a while, does it pump water immediately or is it self priming? The well casing, is it just an open pipe at the bottom or is there a well point?