Stains on steps and vinyl liner

[Grayman43]

Any ideas on what the stains might be. I tried vitamin C test and it did not lighten. Just completed a slam last week.
FC 8
Cc 0
Ph 7.4
Ta 70
Cya 40
To be honest I have not always kept water balance and have rusting on pool ladder. This is picture of pool steps but it’s also on liner .
Thanks

 

[Texas Splash]

Since Vitamin C didn't do anything, try some dry acid in a thin sock if you have any. Those are some pretty dark spots which might be copper. Used any copper algaecides or products with the word "Blue" in them lately?

 

[Grayman43]

Not lately . But those spots have been there for a while and seem to be getting worse. Any idea on rust on ladder. Thinking about replacing it as the steps are coming apart .thanks

 

[Texas Splash]

A rusty ladder sure is trouble, but that should lift with Vitamin C unless the ladder is made from something unusual.

 

[Grayman43]

A really stupid question incoming . I have some PH down (sodium bisulfate) is that ok to put in sock?

 

[Texas Splash]

I have some PH down (sodium bisulfate) is that ok to put in sock?

Yep! That's it.

 

[Grayman43]

Thanks. So do I do it the same way as I do the vitamin C test. Leave the socks on the staying for 3 to 5 minute?