Well pumping sand

I live in MN with a well approx 90' deep and close to 20 yrs old. As soon as the ground begins to thaw the filters in my house begin to plug up with sand. I have a small sedement filter and then a carbon filter. The sand it too fine for the first filter w/100 mesh and totally clogs up the carbon filter. I contacted a local plumber and he suggested either having them check the well screen and lining (roughly $2000) or buying a much larger sand seperator to take out the fine sand ($700).

I have read that in some cases of large amounts of sand in the well can represent that the well walls are beginning to fail. Is that correct? Am I safe with purchasing the sand seperator? and is that the going price?

The $700 is way over priced for a separator. I have a sand trap 'filter' for about half that including shipping.

Sand does not mean that the well is collapsing. The sand may not be able to be stopped without drilling a new well.

Does this sand problem happen only after the thaw, or does it get worse after a thaw? The thawing of the ground should not affect the well screen if the well was constructed correctly.

I have seen wells that make some small sand, and they put an old water heater in line as a sand trap. On a water heater, the water comes in the top and out the top, while the sand settles to the bottom. Where the drain is on the water heater, they put a gate or ball valve to clean the sand out every so often. They claim it works.

Travis