@Mick yes this is about my pool. We have a leak through a power box (dangerous!) and we tested it to see if it came from our pool. In this case it did and my Dad was wondering how to remove the Fe ions from the water that has leaked into the boxes we have put there. In total it has filled 20 foam boxes!!!!’
Probably still require more info, as you allude to Peter. You might be able to rely on oxidation and precipitation of iron, which happens best at a pH above neutral. Adjust with sodium carbonate to get an alkaline pH if necessary. The water could then be decanted off. How will this water be disposed of? You might not need to go to elaborate lengths. You could rely in evaporation, then basically combine the boxes into one and continue the evaporation. Then throw that one box away.