Don't know if this is the right forum, so if not, please move this post! (Moved to Pool School)
Anyway, since pool startup in Sept. 2007, I have been fighting scale problems. The pool was never started up correctly by the the PB. Now that I've done my research, I know they did a poor job by adding only a couple of gallons of muriatic acid, no chlorine, and a quart of sequestering agent. They never performed a single test on water chemistry. The pool never really had a fighting chance to get rid of the "cream" on the plaster and I believe that was a building block for the scale to develop. Also, the PB told me that because I had a SWG, I did not need to worry about CYA because the system was constantly generating chlorine. "Why bother with CYA when you can have all the free chlorine you need?"
Boy was that poor advice. It wasn't until last week when I read the sticky "Water Balance tips for a SWG" that I finally realized what was going on. My months of fighting pH (8 - 8.2+) with gallons upon gallons of muriatic acid now made sense.
Since reading the sticky, I have boosted by CYA from 0 ppm to 60 ppm and my wild pH swings have subsided. Soon, I will be adding borax to get that protection in place as well. Now, I need to deal with the scale issue. In my situation, cost is a concern and therefore I have settled on a couple of different possible solutions:
One, Jack's Magic Stain Solution #2 Treatment (the copper & scale stuff™). I used this before with some success. Of course, I did this when I did not understand why I was having the big pH swings. (Stain Treat #2 Info). The scale came right back because I was not using enough sequestering agent (Jack's Magic Purple Stuff) to keep the silica from re-depositing itself. If the darn sequest test kit didn't cost $70 I probably would have done a better job of keeping the sequestering agent at 20 ppm.
Two, United Chemical's "No Drān Acid Wash" (No Drān Info). I have not tried this and I am not sure it is good for scale.
Unfortunately, the wind is outrageous today so getting clear pictures of the scale is not possible. I will post some as soon as possible.
Regardless, do you recommend either of these products, or is there an economical way to remove the scale (from an entire pool) with gallons of muriatic acid? I'm thinking that if I can get the pH into the sixes and TA into the 20's for a week or 2, and use my big stainless steel pool brush a couple of times a day, I would accomplish much the same as the 2 products listed above. This would be similar to this method (United States Patent 5045211) which I believe is the basis for United Chemical's product.
Thanks in advance everyone for your advice!