Athena StackOverview Stack is a natural plant nutrient made from kelp extract. The nutrients in Stack encourage healthy growth and flowering. Stack gives the plant tools to reach its full genetic potential. When used as a foliar or root drench, Stack helps correct minor potassium deficiencies. Benefits Stack helps correct minor potassium deficiencies.; Encourage healthy growth and flowering; Works with any dosing system: Dosatron, Netaflex, Rhythm; Safe for use