Quote Originally Posted by Nelsonto View Post
I have a 10K fiberglass pool that has iron stains. Although Ascorbic acid works great it makes it difficult to manage the chlorine levels (even with the Hayward SWG). I want to try the stain removal process described in the sticky on the forum but it mentions using Jacks Magic Pink Stuff. After I ordered that I noticed printed on the back of the bottle it states that for salt water pools Jacks Magic Purple Stuff should be used. Is that correct?
I've wondered the same thing. I've been using Jack's Magic Purple stuff for my salt pool (it's worked very well for me), but I wonder if using the Pink Stuff would be more economical since it's more concentrated (I can add smaller doses).

I've tried to find out what's different about the Purple Stuff (other than concentration) that makes it more suitable for salt pools, but no luck.

Interestingly, my pool passes the bucket test for metals (no discoloration whatsoever), but my steps will gradually start to stain if I don't use the Purple Stuff. Another interesting point is the stain only starts to appear when running the SWCG (I've never noticed any staining when shocking the pool in the spring using plain bleach). I was told by the company that installed my pool that the staining is from the small amount of impurities in the salt that gets released when running through the salt cell (there is a return in the steps; perhaps this is why it shows stains first?).

Perhaps next year I might try the CuLator.