Amazon : Pure Aluminum Sulfate (1 lb.), Pure Dry Alum ...
EZ-gro Hydrangea Fertilizer - Added Aluminum Sulfate to Produce Blue Flowers - Liquid Plant Food - Garden-Growing Miracle Nutrients - 1 Qt / 32 fl oz / 946 mL 4.4 out of 5 stars 202 $18.47 $ 18 . 47