I had an Intex pool for 2 years and filled it with very hard water, lots of iron. Here's a small trick I used to do and you could give it a try if you'd like. I lined the skimmer basket with fine window screen and then I stuffed it with fiber fill (pillow stuffing). I stuck my fill hose in there and then left the fiber fill in when I would run the filter pump. Again, this is not a cure, but I think it helped.