I have been using "Jack's Magic Pink Stuff" as a sequestrant in my pool to fight ongoing metal stains. At almost $25 a bottle, it gets pretty expensive. Searching for an alternative online, I discovered "ProTeam Spa Metal Magic" for just $7 a bottle. http://www.hottubwarehouse.com/ProTe...3945-cs40p.htm Is it too good to be true? I tried comparing the MSDS information, but don't know how to determine the chemical concentration.