I don't use it myself, but the below info may help in dosing.Hey also wanted to throw this out there that I have been feeding the girls one tablespoon of Epsom Salt every three days. Is this enough Cal Mag for them or should I do more often? TIA folks!
Dosage for Dissolving Epsom Salts in Water
Mix one or two tablespoons of Epsom salts with a gallon of warm water and give to your plants every four to six weeks. If you are using a foliar spray, just mix one tablespoon in one gallon of water, and spray your Cannabis plants at the beginning of each cycle. Do not spray your plants during the first week of flowering, or while the lights are on. The effect of spraying will be stronger if the temperature in the room is much cooler.
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