There are tons of threads here on the forum about iron control, staining, filtering, and removal. In the end though, it boils-down to a few basic concepts:
- The higher the iron content the more susceptible the pool is to discoloration and staining
- FC cannot be much higher than necessary to maintain algae control; see
FC/CYA Levels
- PH should be controlled carefully, in some cases maintained on the lower-mid 7s based on pool equipment and potential for corrosion
- If refilling from a well, try to pre-filter new water to remove iron particles. Once in the pool, filtering is generally more productive when the iron is precipitating-out; some find filtering with polyfill, towels, or other material in the skimmer useful.
- Use a good sequestrant. ProTeam's Metal Magic and Jack's Magic the Pink Stuff (regular), the Blue Stuff (fresh plaster), and the Purple Stuff (SWG) are some of the top sequestrants. You can also find other brands with similar products, some of which are noticeably less expensive. Sequestrants based on HEDP, phosphonic acid, or phosphonic acid derivatives are the most effective.
- Most ideal scenario .... get fresh water trucked-in
As for existing stains, local spot treatments can be done with Vitamin C tablets. Larger pool staining could require an Ascorbic Acid treatment.