Pickling Lime I dont get it part 2

[Skimmerking]

Lots of people in the US are using this why Can't I get it goign right.
Well I tested the pickling lime in a gal of RO/DI water and used a TSP of Pickling lime and the ALK was at 39Dkh. That doesn't seem right does it then I tried a 1/2 tsp of pickling lime in another gal of RO/DI water and the Dkh was sitting at 33Dkh. so I was thinking that using 1/4 of tsp of pickling lime
what i found was my ALk was going up to 14 with my top off I have a 20 gal tub that i was running for a top off with pickling lime and RO/DI water and now I had to take it off due to the hi ALk in my tank the cal was sitting at 450PPM. can some one shed a little light on this stuff.