Should I add baking soda?

Parameters using Tetra test kit.

KH = 4

PH = 8

CA = 540, high I know - using Oceanic. Stopped Kalk dripping the other day. would like to start again to lower percieved, un-tested high Phosphates.

NACL = 1.025 / 34 PPT

NH = 0

NO2 < .3

Added Phos-Zorb 2 days ago to help fight Cyno.

Am I correct in needing to use baking soda to increase the Alkalinity? I can mathmatically work out the required amount from "Advance Aquarist Online Magazine", if I am correct

Thanks Peter K.