Grow More 6546 EDDHA Iron Chelate, 1-Pound Water-soluble iron supplement for fast uptake by plants EDDHA chelation means far more absorbed by plants than other iron sources Very effective by foliar feeding, also excellent by soil drench 1 teaspoon (about 2.7 grams) per gallon yields approximately 42 ppm Iron concentration General Dosage: 1 teaspoon/gallon