In May 2020, I had a new fiberglass pool installed, so this is the second summer of use. It uses a salt cell for chlorine and cartridge for filtration. I live in North Carolina. Water chemistry results below.
At the beginning of this second pool season, I had a lighting issue that required my pool installer to lower the water a couple feet. It was then that I noticed a white coating on the pool wall. As I looked around in more detail, it's mostly an even coat, but at some points it's a streak. See attached photos. My initial thought was calcium, but my pool is very low in calcium and the makeup water is also low in calcium. When I rub my fingers across it, the white residue does not come off. I put a drop of muriatic acid on one spot and it did not bubble or dissolve the white substance. I tried to manually remove it using gentle buffing with a Scotch-Brite Non-Scratch Scour Pad, but that did not remove it. I tried a gentle auto compound, but that does not remove it either. My pool installer put a couple bottles of calcium scale remover in the pool, but even after weeks that did not help. My pool installer said in the 20 years he has been maintaining pools, he has never seen anything like this before. So I am beginning to wonder if this is a failure of the gel coat, but wanted to enlist the opinions of someone more experienced.
FC: 2
CC: 0
TC: 2
PH: 7.4
Hardness: 75
TA: 60
CYA: 30
I appreciate your thoughts and any recommendations.
At the beginning of this second pool season, I had a lighting issue that required my pool installer to lower the water a couple feet. It was then that I noticed a white coating on the pool wall. As I looked around in more detail, it's mostly an even coat, but at some points it's a streak. See attached photos. My initial thought was calcium, but my pool is very low in calcium and the makeup water is also low in calcium. When I rub my fingers across it, the white residue does not come off. I put a drop of muriatic acid on one spot and it did not bubble or dissolve the white substance. I tried to manually remove it using gentle buffing with a Scotch-Brite Non-Scratch Scour Pad, but that did not remove it. I tried a gentle auto compound, but that does not remove it either. My pool installer put a couple bottles of calcium scale remover in the pool, but even after weeks that did not help. My pool installer said in the 20 years he has been maintaining pools, he has never seen anything like this before. So I am beginning to wonder if this is a failure of the gel coat, but wanted to enlist the opinions of someone more experienced.
FC: 2
CC: 0
TC: 2
PH: 7.4
Hardness: 75
TA: 60
CYA: 30
I appreciate your thoughts and any recommendations.