Borewell in Himachal Pradesh supplying muddy water after installation.

Query regrding muddy water from borewell dug till 310 feet.

Our borewell is drilled till 310 feet and CI pipes are put inside till 240 feet due to presence of hard rock. We have installed 1hp motor at the depth of 210 feet. After flushing the water for many days we didn’t get clear water. But after 20 days water start clearing and we stopped further flushing. However, we get clean water only for after 10 minutes but the clear water still have some traces of minute particles. The water level at our borewell is at10feet depth when full. So what we can do for clear water supply?