Seriously, I don't recommend using baking soda or vinegar.
Vinegar is acetic acid, chemically it is a weak acid.
(Not many hydronium ions go into solution)
This means you have free acetic acid in solution, that's not able to alter the pH any further - to use grower's jargon, it 'lacks buffering capacity'. Bad. Acetates can be formed under such conditions and acetates are poisonous to life.
Use the correct commercial preparation, it will avoid costly errors like "argh all my plants have died"
My argument against sodium carbonate (baking soda) is that (1) you are putting sodium into solution and MJ * hates * sodium. Upsets the Na-K balance. (2) the reaction will tend to liberate CO2 which is not the gas your roots like.