Clear Green Water

[Airwalk2007]

Hi,

I have a 28' round vinyl above ground pool. It was filled from a well and I knew that the water would turn brown and it did when i added the first batch of water last year. It was all fixed by adding some iron mite overnight. Now this year im having problems. I filled the pool to the normal level and started the chemicals all my levels were balanced and the water looked great. About a week after my water started turning a light green color. The pump runs 24/7 so I know it is not algae because its clear green. I have added iron mite again and it’s back to perfect levels and perfect clarity. But about 2 days after I add the iron mite the water slowly turns back to a clear green. My filter keeps needing to be backwashed about every day because the pressure builds up so much and the water doesn’t return as strong to the pool. Once i backwash the filter, the return water enter the pool is a rusty brown color for about 20 seconds. Does anyone else know how to fix this so I don’t have to just keep adding more iron mite and backwashing? Please help