I have an odd stain problem I have been unable to rectify. I'm not even sure if "stain" in the correct terminology as this seems to be more of a deposit. I have small, the size of a head of a pin, reddish-brown spots on the vinyl liner and fiberglass stairs of my pool. In many cases I can pick them off with my thumb nail but not always. I have tried Jack's Magic Stain ID kit with no substantial positive results. I have tried citric acid in a sock as well as vitamin C tabs with some, very minor improvement. A chlorine puck does nothing. PH Down (dry acid) does seem to help, especially on the fiberglass stairs.
Here are my numbers from last season
PH 7.5
Alkalinity 90
Chlorine 4.0
CYA 55
Any ideas?
George
Here are my numbers from last season
PH 7.5
Alkalinity 90
Chlorine 4.0
CYA 55
Any ideas?
George