i had installed a new tube-well at 120 ft with 60 ft filter. after running well for 5 months it suddenly started giving dirty red water.the motor is running well and the water output is also correct. according to the driller the casing pipe has developed a hairline crack and a new drilling will need to be done. is that the only solution or can one lower a 7inch casing into the 9 inch casing and rectify the fault. Please advise. Regards Sham