You want to use SODIUM FREE seltzer water if you are growing indoor or greenhouse and just as a foliar spray... I think this makes plants blow up... I have used it many times and it's a huge co2 boost that the plants love... But no sodium... SALT IS BAD..... Spray the leaves when it's hot out or in and spray untill the leaves are weighted down and sagging.. CO2 is a heavy gas that does not rise like most gases, it falls... SO not only does this give your plants a great CO2 boost, but it's a workout for them as well with all the added weight. Which in turn is acting like a fan does of sorts.. preparing your stock and stems for the much anticipated weight to come... You watch, on a hot day, your plants will drink many doses of that water and never will they hate you for it.... Do not spray when flowering unless it is a very light mist and the light will be there to help the plant drink and evaporate the excess water... You don't want to overspray and get mold gowing... Most people would say not to spray foliar at all when they are flowering, but you can... Just be careful. All that you have read is tried and full on true!