Epsom salt. Used to raise the sugar content in cantaloupes and watermelons. Foliar apply weekly for 2-6 weeks before and
during harvest at the rate of up to 4 lbs/acre.
A $ 13.65 flat rate box holds 4-5# bags and ships anywhere in the US
The recipe for use in a hydroponic system is 12 grams Masterblend 12 grams calcium nitrate 6 grams magnesium per 5 Gallons