General Hydroponics - FloraMicro Hardwater (5-0-1) if your tap water is over 200 ppm (or contains Calcium above 70 ppm). If your water contains 30 to 50 ppm Calcium, you can mix our original FloraMicro with FloraMicro Hardwater to create a perfect Micro blend for your plants. Provides Nitrogen, Potassium, Calcium, and trace elements.