What caused turbidity in artesian well water?

We installed a Lindsay EcoWater multi-purpose filter in April 2011, ETF2100PF. We have had problems with rust/iron and turbidity in all of our toilets, sinks, and bath tubs. The unit was replaced last month with a Series 3500R30. We are still having problems and have to clean everything in the baths and kitchen daily to rid the rust. After Lindsay has continued to test the water, they say has turbidity in the water. They have been very helpful in answering our calls concerning the rust problems. However, we are very frustrated at this point. The original EcoWater system replaced an existing Culligan system in 2011. Same problems with the older filter - rust. We replaced the artesian well in June 2011. The old artesian well had been infused with road salt due to a crack in the casing and was not useable.
Any suggestions as to what is causing the turbidity? Do you know of any remedy available? Thank you.
Pat Fisher