Please bear with me as I am new to this .
I recently noticed a discoloration mainly on the spa seat and floor. Not sure what it might be. Pictures are attached (disregard crosshatch pattern as it is a shadow from the pool enclosure overhead).
Pool chemistry is checked weekly at local pool store. Most recent readings on 5/31/16:
PH 8.0 (MA added to reduce it)
SALT 3,000 (salt added)
File Jun 02, 12 07 48 PM.jpgFile Jun 02, 12 08 19 PM.jpg
Sorry for the quality of the photos, but it is shooting through the water naturally. Ty.