Hi all,
The walls of my 3-year-old fiberglass pool have a texture under the waterline compared to the smooth texture above the waterline. It's not like sandpaper grit or chalkiness but there's a definite texture that doesn't belong there and wasn't there for the first couple years. There is no change after vigorous brushing and scrubbing so not sure if it's a residue/scale that has built up or if it's some kind of erosion or pitting of the gel coat. I have been brushing ~weekly.
Here is my chemistry:
visual: clear water
FC: 7.5 (currently a little high as I've recently been battling some persistent haziness; on the way down to my target of 5)
CC: 0.5
pH: 7.6
Alk: 100
CYA: 70
CH: 250
Temp: 82F
Sat index: +0.1
I needed to SLAM twice this year to control cloudy water. For that I used cal-hypo but otherwise I use my SWG as my chlorine source. It's not clear to me whether the cloudy water issue is somehow connected to the wall texture issue, as I'm currently thinking the cloudy water was due at least in part to an aging and dirty filter since the cloudiness went away without SLAMing once I replaced the CC200 filter.
I've read though some of the other threads here relating to fiberglass pool shell problems but haven't found anything that sounds specifically like my problem. I don't see any visible sign of what I feel and I can't scrape off any residue. That said, I gather the most likely explanation is some kind of scale, but how do I test for scale below the water line? Are there any other tests I can do to investigate the cause?
Thanks
The walls of my 3-year-old fiberglass pool have a texture under the waterline compared to the smooth texture above the waterline. It's not like sandpaper grit or chalkiness but there's a definite texture that doesn't belong there and wasn't there for the first couple years. There is no change after vigorous brushing and scrubbing so not sure if it's a residue/scale that has built up or if it's some kind of erosion or pitting of the gel coat. I have been brushing ~weekly.
Here is my chemistry:
visual: clear water
FC: 7.5 (currently a little high as I've recently been battling some persistent haziness; on the way down to my target of 5)
CC: 0.5
pH: 7.6
Alk: 100
CYA: 70
CH: 250
Temp: 82F
Sat index: +0.1
I needed to SLAM twice this year to control cloudy water. For that I used cal-hypo but otherwise I use my SWG as my chlorine source. It's not clear to me whether the cloudy water issue is somehow connected to the wall texture issue, as I'm currently thinking the cloudy water was due at least in part to an aging and dirty filter since the cloudiness went away without SLAMing once I replaced the CC200 filter.
I've read though some of the other threads here relating to fiberglass pool shell problems but haven't found anything that sounds specifically like my problem. I don't see any visible sign of what I feel and I can't scrape off any residue. That said, I gather the most likely explanation is some kind of scale, but how do I test for scale below the water line? Are there any other tests I can do to investigate the cause?
Thanks