Okay, I have a problem. We have a very old (c.1930) in-ground swimming pool, which has a built-in iron ladder (built-in, as in sunk into the concrete wall) and an iron drain-fitting. When we bought the house and drained, scrubbed, and painted the pool last year, I got the surface rust off of both before painting them, and for last year, that sufficed.
But this year, the rust returned: the ladder rungs have pits and other surface irregularities with plenty of corrosion, and the drain-fitting has several places around its circumference that are rusting as well. This means I have a seemingly unavoidable--and high--iron content in the water. I've not had the water tested, but it tends toward a clear green tint and as much as I try (using metal remover and keeping the Ph on the lower side: 7.2-7.1 or so), there is always a slight greenish tinge.
This fall, I plan to drain the pool for repainting in the spring, and I suppose at that time I could simply saw off and remove the ladder. But does anyone have ideas about other possible solutions?