Magnesium, aka Epson salt. This can be found in any big box store or drug store. I get it in 5lb. bags and it is cheap. I dilute 1 tablespoon per gallon but some folks just sprinkle it on the potting soil and water it in.
drdawg (Dr. Kenneth Ramsey)
The reason it's so hard to lose weight when you get up in age is because your body and your fat have become good friends.