First some numbers on my fiberglass pool (8,000 gallons):
Free Chlorine: 6.8
Total Chlorine
pH: 7.4
Total Alkalinity: 71
Calcium Hardness: 154
CYA: 81
I have been having a constant battle with what I believe is metal staining. The walls of my pool are light brown and my water is crystal green. The stain removes instantly with ascorbic acid, which makes me think iron. But the crystal green my water turns after adding chlorine makes me think copper.
I have attached a photo of how my pool looks now and how it looks an hour after using Metal Out.
It seems the only permanent solution is draining and re-filling, but I read you should never drain a fiber glass pool.. any ideas are much appreciated.
Free Chlorine: 6.8
Total Chlorine
pH: 7.4
Total Alkalinity: 71
Calcium Hardness: 154
CYA: 81
I have been having a constant battle with what I believe is metal staining. The walls of my pool are light brown and my water is crystal green. The stain removes instantly with ascorbic acid, which makes me think iron. But the crystal green my water turns after adding chlorine makes me think copper.
I have attached a photo of how my pool looks now and how it looks an hour after using Metal Out.
It seems the only permanent solution is draining and re-filling, but I read you should never drain a fiber glass pool.. any ideas are much appreciated.
Unless you used a generous amount of copper algaecides in the past, it would appear that is from iron. The AA confirms it. The color hue could just be from the color of the shell that is throwing you off. Certainly the most ideal way forward would be replacing the water with non-iron water, but us FG owners must be careful. Since you would have to have fresh water trucked in, you would probably have to do it in stages which certainly is not as efficient and probably pricey. But you can lower your water level to about 12 -18 inches at a time for a truck or before a heavy rain. Below is one of my favorite iron testimonials. Take a look. You may be able to do something similar (in concept anyways) to help remove some of the iron.
