Help with yellowing plaster in the bottome 6 inches of spa

[Randi]

Our pool and spa are less than 1 year old. The plaster is cody pebble and I recently noticed that the bottom 6 inches of the side wall in the spa is yellowish. We had an issue with an electronic valve that drained the spa briefly last week so I poured bleach along the yellow ring prior to re-filling the spa but that didn't seem to diminish the yellowing. The valve problem did diminish chlorine levels briefly but that was after I had noticed the yellowing. Any suggestions? Many Thanks from Austin

 

[Bama Rambler]

Re: Help with yellowing plaster in the bottome 6 inches of s

Welcome to TFP.

Try rubbing a vitamin C tablet on it and see if that lightens it. If it does it's metal staining. If it doesn't try holding a trichlor tablet on it.

 

[Randi]

Re: Help with yellowing plaster in the bottome 6 inches of s

Thanks, I'll get some vitiman C & give that a try this weekend. Cheers