The use of the metal trap filters helps get rid of iron in the pool water. A product like the Liquid MetalTrap which works with a wide variety of pH will be able to get rid of the iron in the pool water.
Try one of those Mr. Clean magic eraser sponges. Just dip it in the pool water and wipe everything down. I used it on my pool steps and they look like new. It is very non-abrasive. Let me know what you think. The brown to yellowish stains can re removed with acid.