pH stabilizing is important to minimize fish stress. The KH (Carbonate Hardness) of your aquaponic system water should be at least 4.0. Ingredients: Potassium Bicarbonate Directions: Use our API KH and GH Test Kit to evaluate your current KH levels. Dissolve 2 1/2 teaspoons (12 mg) in system water to move 100 gallons of water 1 KH level. Repeat until desired KH is achieved. Individual results will vary. Storage: Store in a cool, dry area. Handling: Avoid breathing dust. Wash thoroughly after handling. Do not reuse containers. Caution: This product may cause burns, handle with care. Avoid contact with skin and eyes. In case of contact wash from skin or eyes with plenty of water for several minutes. If swallowed, call your physician or Poison Control Center. Proper use, storage and disposal is the responsibility of the user. Protective gloves and eye protection should be worn.