This is a question worth answering plainly, because the usual product recommendation does not do what the question asks. A sand filter fitted in the normal domestic position sits after the pressure tank, which is downstream of the pump, so every grain of sand has already been through the pump before the filter ever sees it.
What sand does to a pump
A submersible pump running on abrasive water wears its impellers and diffusers continuously, losing output gradually long before it fails outright, and the wear accelerates as clearances open. Seals are scored by the same abrasion. Jet pumps suffer at the nozzle and venturi. Pressure tanks accumulate a layer of grit at the bottom that stirs up under heavy demand. None of that is recoverable, and none of it is prevented by anything fitted after the pump has already done the work.
What actually protects the pump
Downhole measures, which are well work rather than plumbing. A properly sized and intact well screen matched to the formation. Repositioning the pump higher in the borehole so it is not drawing from the sediment layer at the bottom. A pump shroud or flow sleeve to control where water enters. And reducing the draw rate where over pumping is pulling fines into the borehole. All of those require a well contractor and address the cause rather than the output.
What the filter does protect
Everything after it, which is not nothing. The treatment train, the plumbing, the appliances and the fixtures all benefit substantially: softener resin channels and abrades on grit, membranes foul, UV sleeves cloud and lose transmissivity, cartridge filters blind within weeks, and tap cartridges and appliance valves wear. A centrifugal separator or a backwashing media tank first in the train handles all of that continuously. It is worth fitting, just not for the reason the question implies.
Ask why there is sand at all
A well newly producing coarse sand has a cause: a failed or wrongly sized screen, a pump set too low, over pumping, or a collapsing formation. Every one of those is degrading the borehole and the pump while a filter quietly handles the output, and the eventual cost is a pump and possibly a well rather than a cartridge. Have the well assessed first, then filter what remains. Our iron filter guide covers the rest of the train downstream.
Questions people ask about sand filter for well pump
Will a sand filter protect my well pump?
No, in the usual position. It sits downstream of the pump, so sand has already passed through the pump before reaching it.
What does protect the pump?
Downhole work: an intact correctly sized screen, repositioning the pump higher in the borehole, a shroud, or reducing the draw rate.
Is the filter still worth fitting?
Yes. It protects the treatment train, plumbing, appliances and fixtures, which is substantial even though the pump is not included.
My well suddenly makes sand, what should I do?
Have it assessed. A failed screen, a pump set too low, over pumping or a collapsing formation all damage the well and the pump.