Stains on my steps

[techman65]

Hi,

I'm trying to identify some stains on my pool steps. Any guidance on what type of stains these may be and the best strategy for removing them? I have tried rubbing vitamin C on them and they only lighten very slightly. I have also tried pouring bleach directly over them and haven't seen any change.

Thanks for any insight.

 

[Mr Bruce]

That looks like algae to me. What happens if you set a puck on them for 15-30 minutes?

A full test result would be good also

 

[techman65]

Unfortunately, I don't have any pucks at the moment. I've pretty much been using bleach exclusively and don't have any left over from pre-TFP.

I'll do a full test result and post as soon as I have a chance.

 

[techman65]

I was at Walmart last night stocking up on bleach and noticed they had a single chlorine puck available for sale. Picked one up and placed on one of the black spots overnight. When I checked it this morning, the spot was clean. Moved it to another spot this morning and will check again when I get home from work.