m0useanswered grow question 3 years ago NO it is not ok.
baking soda is Sodium Bicarbonate. - NaHCO3 - sodium hydrogen carbon oxygenx3
PH up is Potassium Hydroxide KOH - potassium oxygen hydrogen
PH down is phosphoric Acid. H3PO4 - hydrogenx3 potassium oxygenx4
Your will add way to much sodium to your soil.
Both have the effect of raising the PH {KOH or NaHCO3}, but they have different uses in function and the products remaining after reaction.
Same as acids, battery acid is acidic but you don't put that on your french fries, you use vinegar for the exact same reasons.
Everything has a PH but everything is not interchangeable.
PS don't use vinegar to PH down, it kill the soil microbe life.
It gets even more complicated with concentrations and affinity for things.
but lets not get into that
End result, no; not ok