I think Randy used Coralife salt mix on his driveway.
I picked up a bucket from my LFS last week end. I still haven't opened it. The RC from June from Foster/Smith tested out to:
Cal: 420ppm-salifert
430ppm-lamott
Alk: 12.8DKH-salifert
Mag: 1320-salifert
I will open the "new" bucket tomorrow and mix some up to see what I get. FWIW I dump half a new bucket into another bucket and shake it. Shake the remaining salt in first bucket and mix them back together and shake it again. Not all grains are the same size and I'm sure some has to settle to the bottom. Could affect the readings but might not at the same time.