Attached is a picture of a stain that I am trying to get off of my steps in my vinyl pool. The stain originate from the return jets by the steps and goes down the side of the steps to the step below. They were present when i took the cover off this season. Almost looks as if something oozed out of the jets and stained the wall and then sat on the step. They weren't there when the crew closed the pool. They have become lighter as the pool season progresses. Started as a darker brown/yellow and are now a lighter yellow.

I have tried the following with no success:
- Jack's Magic Stair Stuff
- Bioguard Iron Stain Remover
- Bioguard Copper Stain Remover
- pH Down in a stocking
- Vitamin C in a stocking
- high levels of shock/chlorine

The only thing that seems to do anything is chlorine tablets directly on the steps - and that seems minimal.

Pool chemistry is balanced. Bioguard chemicals are used in the pool (Smart shock, Silk sticks, and Backup algaecide).