If soda ash is sodium carbonate (Google says it is) and 'kent turbo calcium' is calcium chloride, then yes, adding the two (one at a time) to your water should be the equivalent of a 'balanced' alkalinity and calcium supplement (respectively).
If soda ash is sodium carbonate (Google says it is) and 'kent turbo calcium' is calcium chloride, then yes, adding the two (one at a time) to your water should be the equivalent of a 'balanced' alkalinity and calcium supplement (respectively).
While it seems you can add both those products, I am not sure Greg is commenting on whether your ratio's are correct. In order to know the ratio, you need to understand the concentrations of each and a whole lot of chemistry. Since I know neither, I cannot say whether the two amounts are indeed equivalent to the consumption of your tank. The wonderful thing about the ubiquitous 2 part is that you add the same amount from jug 1 and jug 2, and both are consumed at the same rate. Using two separate products will fulfill the need to alk and ca, but not with the same simplicity.
Disregard that 1/4 tsp per gallon as it's meaningless (it appears that's a daily dose to be added to your top
off, although the folks at Kent have no idea how much CA your tank needs daily.)
You'll need to do some math to figure out the balanced dose. If it was me, I'd toss the "Turbo calcium" and simply buy a tub of the BRS CA and mix it using their directions. Then you'll have 2 jugs that can be dosed in equal amounts.