Yellow stain on steps from chlorine tablets

[waterbear]

If the steps are plastic the stains might be permanent (much like the yellowing chlorine bleach will cause to nylon fabric in the wash). If they are fiberglass then I would like to see your water test results and would like to know how they were done (strips, test kit and brand, pools store and how they tested, etc.) because there might be a way to remove them since they very possibly are not directly from the chlorine by might be a metal stain that the high chlorine level at the site of contact caused.

[PoolDoc]

Put some Vitamin C tabs on the steps, to rule out iron. If Vit. C clears the area around the tab, it IS an iron stain. If not, it may be chlorine oxidation, which is probably permanent.