If you have iron staining the first thing I would try is dropping your pH to 7.2 and adding a double dose of sequsterant (Pink stuff or purple stuff if you have a SWG....I personally like ProTeams Metal Magic over the Jack's Magic line. You will need to add a maintenance dose of sequesterant monthly to keep the stains away (even though the bottles say add it weekly I have not found it to be necessary to add it that often). Also, don't let your pH go above 7.6 since high pH is one of the factors of stains returning! Run your pump for 14-48 hours after dropping the pH and adding the sequesterant and this might take care of the stains. Be aware that your water might get cloudy....this is normal. If it doesn't remove the stains you will need to treat with ascorbic acid. Mbar (Marie) is the forum's expert on that!
The most important thing is to try and figure out where the iron is coming from. Having your pool water and fill water tested for iron is a good idea.
If this doesn't get rid of the stains start a new thread about the staining and you will get all the help you need with the ascorbic acid treatment.