I have had this pool at a rental house with the comfort that my local pool service has been keeping up with their end of our $75 per month contract. Boy was I surprised when my tenants moved out and I found that my SWCG had burnt up (but that's another story) and the service tech had been chlorinating by hand (not sure how or for how long). There was calcified material all over the spa waterfall tiles, and the bottom was filthy. After an enjoyable conversation with the pool service, I began to clean the mess.
I scraped the tiles and got them clean. Vacuumed and brushed the pool and washed the dirt out of the filter. I noticed these stains on the bottom of the pool and some on the steps. Were never there before and is the only part of the filth that I cannot clean no matter how much I brush it.
I let it run a bit then did a water test.
PH: 7.8 (or more as that is as high as my color goes)
CYA: 100 + ?
I was able to get a new SC-36 salt cell that day and got it replaced. Added 120lbs (3 bags) of salt, and 3.5 cups acid. Let it run for a few days.
FC: 5+ (highest I can test)
I am in the process of adding acid to get the PH and TA down. Has a waterfall and SWCG for aeration. Not sure of the CYA measurement so keeping the FC as high as I can for now.
Any help identifying this stain and suggestions for removal would be greatly appreciated.
[attachment=2:jsj45m3j]Pool Stain 1M.JPG[/attachment:jsj45m3j]
[attachment=1:jsj45m3j]Pool Stain 2M.JPG[/attachment:jsj45m3j]
[attachment=0:jsj45m3j]Pool Stain 3M.JPG[/attachment:jsj45m3j]