Paydirt!!! Thanks Jecco. I called the three Memphis Pool Supplies in town; the one on Getwell doesn't carry Dowflakes (they have some other brand). But the Germantown (7605 Poplar) and Collierville (930 W. Poplar) stores do. 50 pounds for $29.95.
With going back and forth between the two part calcium/alkalinity additive and kalkwasser, I have gone through 4 pounds of Dowflakes in about 6 months (I've got a SPS heavy tank), but I think I can get by with 25 pounds for 2 - 3 years. Does anybody want to split a bag of Dowflakes? If not I'll just keep the rest for my hot tub! (hhmmm, my hot tub has calcium, alkalinity, pH balancers... I wonder if I can use that as a frag tank??? ;.)
And unless anyone knows of a local source for Magflakes, I think Buckeye Field Supply is still a great source for MagFlakes, which is magnesium chloride, and you combine MagFlakes with epsom salts (magnesium sulfate) that you can get at any Walgreens or Krogers. But magnesium consumption is probably only 10 - 20 % of calcium consumption, so an 8 pound bag of Magflakes should last me at least 2 - 3 years.
Jay