I use two tablespoons of molasses in the last two to three weeks of flowering. I use it back to back for two weeks at least, and the third if i have to. It helps feed microorganisms in the soil, and helps create denser, and better tasting buds. Helps to use about 1/4 gallon of hot water to dissolve the molasses, then add the other 3/4 colder water and shake good to mix it up.
My plants love it and i see a giant swell on all my plants that get this flush for two weeks. They taste incredible too!