To some growers its a supplement or source for the provision of magnesium whereby tap water applicable to your home is lacking. At a rate of 1tsp per gallon or so of water. Not an experiment i have or would undertake but its supported by many experienced growers.
Treats magnesium deficiency. Its only oxygen sulhor and magnesium.
As with many a debated topic!
Claims of yellowing leaves reverting to green once again? Thats if you know that magnesium defic. is the so called culprit?
More experienced growers will claim its properties are good but ofcourse experienced growers can tweak their care approach often as most other factors have been previously observed and successfully concluded. Two seperate potted plants, one with and one without!? But many experiments tests and trials are unfounded due to many contributing factors we often overlook! or forget!