First of all, thank you for taking the time to provide assistance I appreciate it. This question is in regards to having a re-occurring off-white/beige metal stain that forms at the water line and down to the floor of the pool.
Last year was the first year in which we had the pool and after having it opened, we noticed that after a month or so, we were having this beige/off-white stain on the walls of our fiberglass pool. Since I keep track of my pool readings, I was able to trace it back to the consistent shocking of the pool every other week, and not having any sequestrate in the pool and that it was most likely a copper metal precipitating on the walls during high levels of FC. After a lot of back and forth, and a lot of learning on this forum, I found out that since I was using the 3 inch pucks that my CYA was well over 100. My PH was always low, around 7.2 and my CYA was high, and because of this, my 2-3 PPM of FC was never effective of keeping my pool clear and not cloudy. (Hence the shocking). After learning about this, I did an Ascorbic Acid treatment and then roughly drained half of my pool and refilled. This lowered my CYA down to around 50, and with the use of "No Mor Problems", and switching to bleach as my source of chlorine, was reduce the shocking of my pool to maybe once over the remaining 2-3 months of the season.. The stains eventually returned, but they weren't as dark and it took much much longer... At that point I simply did another ascorbic acid treatment, and they cleared up for another month.
In addition, I came across the "Hamilton Index" on the United Chemical website and switched over to this balancing, which I am hoping, aided in the reduction of staining. (I kept my CH around 200, my TA around 95 and my PH around 7.8).
After much research, I made the switch to a SWG. When I opened the pool the pool was green and dirty, but absolutely no stains. After clearing the water, my PH was around 8.4, in which case I adjusted down to my 7.8 and brought my TA up to the 95 range. My pool stayed clear (with the cooler weather) and absolutely no staining. I was consistently using "No Mor Problems" weekly, which as you know, made it absolutely difficult to determine what my FC level was. When I started the season I had my SWG set at a 12 Hour Cycle at roughly 40%. This worked well, but the pool water was in the 60-70 degree range. After I got back from vacation, the weather warmed up considerably and we started heating the pool to around 82 degrees. Since I was still unable to get a FC reading with the No Mor Problems, I wanted to systematically determine what the FC levels were that I was adding to the pool daily.
After doing some research, I found that my Hayward Aquarite was able to produce around .60 Lbs of Chlorine Gas per day on a 24 hour, 100% max output. After knowing this, I found that with my 12 Hour cycle I should have had my output set at 100% (adding roughly 3 PPM FC per day). During this time, I took my pool water to the pool store, and the guy (who sounded knowledgeable) said that I should have kept my PH around 7.4, TA at 80, and I needed to raise my CH to 250-300. After this discussion, I added in CH to bring it to 300 PPM and then started maintaining my PH at 7.4.
After all of these adjustments, within 4 days I started seeing the stains coming back. I am not sure if it was the FC going too high (the 3PPM being added daily building up), or if was the lower PH, or if it was the higher CH, but the stains started coming back. Eventually the light beige stain around the walls turns the water from a nice blue to an off-blue/green, and when you move the water around you are able to see the stains on the wall.
With that being said, I am moving back to the Index I used last year which produced the best results, but I wanted to get buy-in since it deviates slightly from what TFP says is ideal.
The "Hamilton Index" How to Balance United Chemical Corp worked well for me, and I'd like to adjust and maintain my levels at:
FC: 1.0 PPM
SWG T-Cell 3: 50% at 12 Hours
In addition, I intend to figure out exactly what my FC is at a 50% setting and then adjust for 1.0 FC and then continue to use the "No Mor Problems" weekly.
I am also adding a weekly maintenance dose of "ProTeam Metal Magic" as a sequestrate (even though I've never been able to get a positive metal reading in my pool).
I am also going to try and prevent having to shock my pool at all.
If anyone has had this issue before, or can weigh in on it, or can validate or invalidate my approach, I'd greatly appreciate it. It has been unbelievable frustrating for me as a pool owner. Especially since we only can really use the pool June, July, and August in NE PA.
Again, thanks for your time, I really appreciate it!