how do I determine the WELL POINT SCREEN SIZE

[KHB1]

First I would like to say I just found this site and I want to express what a great place to read and the knowledge offered by contributors.
I am retired, live 100 miles from a property I own 5 miles from the Atlantic Ocean. The closest house or road is over one half mile away. I have a self contained travel trailer and camp there often. My main use is for a large garden and the wife and I enjoy fresh and canned organic vegetables. Six years ago I drove a well there with no knowledge of what I was doing to a depth of 43' with a static water level of 13' the well was ok for some time but it got to the point I could not get water with the pitcher pump. I built a 36' X 36' storage building and placed open topped barrels under the eaves to catch rain water. This year has been dry and irrigation has been sparse.
I want to wash in a well there and don't want to make the same errors I did before.
I am only planing to use the water for irrigation and some sand is no concern to me
The only advertised well driller in the county is very uncooperative and will share no information.
Question #1 how do I determine the size screen point to use
If I use a 2" casing pipe with a 3/4" wash pipe in the center I should be able to sample the sand at different depths and measure (micrometer) the granules from the up flow.
Question #2 is there a collation between the gradual size and well point mesh size
Thanks in advance KHB1

 

[Speedbump]

If you wash a well in, you will be bringing up the material that is down in the aquifer your going into. If you have a good enough water flow, you will bring up small and larger pieces of material (sand mostly) so you can size the screen accordingly. The very fine material will come through for a while during development of the well, so don't get a screen for the very smallest pieces. Kind of go in the middle of the road with sand size. A slot screen will yield a lot more water than a gauze screen. The screens you see at the big box and hardware stores will yield the least.

bob...

 

[Sponsor]

 

[KHB1]

Thank you Bob for the advice I was thinking that would or should be the case. Would you recommend a reasonable supplier?
Thank s again KHB1

 

[Speedbump]

I have several 1-1/4" Stainless Steel slotted points. They are all around 3' long and differing slot sizes. I also have some 3' extensions to make them 6' long. $50.00 each plus shipping. We don't use them here, so it's a bargain.

bob...

 

[Masterpumpman]

Use a large slot size!

I'd use a large slot size (not more than .020" slot) and not over a 3' point. This will be plenty for a pitcher pump and maybe even a 1/2 hp jet pump.

Before using a 2" PVC for an outer casing check to see that the 1-1/4" drive point and couplings will fit through the 2" PVC.

I'd wash the 2" PCV pipe down to the sand as you described, Then drive the sand point into the sand as far as you can. Ideally to prevent the pump from sucking air, the top of the sand point will be at least 25' below the surface but if not try it anyway.