I've recently become the owner of a 1,800 gal, 3 y.o. swimspa with I believe an acrylic surface. Around and above the waterline, the surface has a whitish colour to it. Not a thick rough/textured layer deposited on the surface, just a super thin layer that appears more as a whitish discolouration.
As a background on the pool, when I moved in to the house the pools's water parameters were:
FC - over 100
CC - 0
pH - approx 8.2 (couldn't really tell with high FC, but after bringing FC down and reducing TA it's still a bit high)
CH - 110
TA - 170
After a bit of work, it's currently at:
FC - 4
CC - 0.5
CH - 110
TA - 145
CYA - about to add some, I decided to get FC under control and the SWG tuned in a bit first.
I know chlorine can bleach some surfaces, but will it do this to acrylic? And I haven't noticed it below the water where it was constantly exposed, only above. However as it isn't real bad the water may tend to hide the effect.
Is it likely to be from the chlorine? Or could it be calcium carbonate deposited on the surface? CSI when I moved in would calculate out to 0.5 (assuming pH 8.2) which is a little high but not excessive.
What is the best way to try to clean it? Dilute acid? What strength? Or something else?
Thanks in advance,