A week ago I had green algae in my bromine hot tub. I used algaecide and non chlorine shock. I go out of town for 3 days. I come back, water is bright yellow. I try non chlorine shock again, and yellow-rid. Didn't do a thing for the yellow. I drain hot tub. Vinyl is completely stained yellow (was white). I try rubbing vitamin c on it (ascorbic acid), doesn't even touch it. I try vinyl cleaner from the pool store, no go. I refill hot tub, this time I put a crapton of metal prevent in it and chlorine shock. Let it sit for 2 days. Drain again. Vinyl still yellow. I fill it again. This time I dump two bottles of liquid vinyl cleaner in it, let it sit for a day. Drain it again. Still yellow.
Is there any way at all to get rid of the yellow staining, or do I now have to convince my friends they aren't hot tubbing in pee?
Pics here
https://imgur.com/gallery/S4409
