CO2 - soil vs air? Any experience?

Hi all,

I've done some searching, but I've not found anything more recent than a couple years back anywhere about this.

I'm about to start a home-made CO2 addition with egg shells and vinegar to add just a little... But while looking into info on this, I found some people talking about using CO2 tablets to add it to the root system? And that doing so allows the plants to use more of it and less is able to dissipate?

Does that make sense? If so, wouldn't using soda water make sense when watering plants? Anyone have experience or hard data to back this up? So strange.

If it does seem to make sense, I'm wondering if it may help my next grow. Heck, I'm looking at this plus photoperiod manipulation to see what can be done to help increase yield per space, too. :)