I generally like to get it at Sun Pools on rt 22 in Greenbrook. National Pools also used to sell it, but the rt 22 store east of Sun Pools closed and if there are others, I don't know, as has Branch Brook (Napco). Pelican Pools on Rt 10 in Randolph(?) and other places sells, I think, 2 1/2 gallon jugs--costs a bit more that way. Search by phone. I like Sun Pools best because when I test their 12% it always comes up at 14%--they turn over a HUGE amount each season. Branch Brook's "12%" tested at around 9-10% making it a poor deal and meant it sat too long. Rix Pools in East Hanover on Ridgedale sells the 2 1/2 gals--I think.