Muddy water coming out of borewell

Dear Sir,

We had constructed a new house 11.5 years back. The bore is 120 ft. The contractor has fixed a one hp submersible pump. The construction was finished last year Feb 2020 but because of corona pandemic; we kept the house locked. After September 2021 we had let it out and the tenant was using it and water was fine. Two months back, we moved in. Now the problem started the borewell is pumping muddy water. We had checked with the plumber. He raised the motor from 80 feet to 50 feet. Still the problem continued. Last week we cleaned/flushed the borewell. A lot of mud came, but after sometime the water was clear. Suddenly the water started to become muddy. The fellow who cleaned is saying the borewell casing pipe is broken somewhere so mud is slipping inside. You can use this bore and you need to dig a new one. But we enquired in the nearby houses, one house had the same problem and they have 1.5 hp submersible pump. They had fixed water filters/purifier (the blue one) and sintex tank and now they pump water into the sintex tank and leave for one day and then pump it to the overhead tank thru the filter. Now they have no issue. Another nearby house has 120 ft borewell and using a jet pump and they have no issue. We had also installed filters and Sintex tank but with no vain. The filters are not working.The mud is very fine sand. Kindly advise can I try Jet pump or I need to dig a new borewell?