The two issues I see is

1) Iron. You don't want to put well water in your pool if you have a high Iton content (Uness you have or want a rusty looking pool. If you have an Iron filter that will remnove the metals and silt. For Iron Filters to work you need a PH over 6

2) The Second issue is bacteria, Now if your well water is untreated (Chlorine or UV) your pool chlorine should be able to take care of it but it may be risky.