This spring I've been trying to tackle an staining issue in my pool. Over the last few years we noticed an orange stain starting/growing, and when I opened the pool this year I hit my breaking point. The water was no longer blue and had no shimmer. After a lot of reading I dug out my StainFree and gave it a shot.
I started by dropping my FC to ~0. pH was lowered to just below 7.2. TA was 70. I added Poly' 60 per the directions on the bottle. I added the StainFree in two different sessions and BOOM the pool was blue again with no staining at all. Even our drains, which had turned a dull brown color, had brightened back to the original glory! I followed up the treatment with two bottles of Jack's Magic Purple (Salt Solution) and figured I was on my way to a stain-free season.... until I noticed a few orange spots start to reappear.
It seems my TA dropped down to around 50 while I wasn't watching. Would this cause the metals to fall out of suspension? pH is still just below 7.2 and FC is 0. The water is still clear with no clouding.
I've just added enough baking soda to get the TA back up to 75-80. I'm hoping this will get me back on the road to clean, but figured I'd ask here to make sure I'm not missing something.
Here's a [pleasing] pic of the pool right after the StainFree treatments. The small stains I have now showed up a day or two after this photo.