Regarding you alkalinity reading....This is from memory but I think its right...

Your test reads as mg/l which, for the layman is ppm

to convert to the more familiar dKH or meq/L....

50 ppm=1meq/L=2.8 dkh....

So your reading of 140mg/l or ppm is 2.8 meq/L or 7.84dKH

Check my math....