Common elements found in hard water: Hard water is formed when water percolates through deposits of limestone, chalk or gypsum which are largely made up of calcium and magnesium carbonates, bicarbonates and sulfates. Why do you need to descale your water heater? It is recommended to descale your tankless water heaters every 6 months as limescale builds up from hard water. Depending on the mineral content within your local water supply system, large amount of limescale buildup may deteriorate or damage your essential water heater as well as other household appliances. Tankless Water Heater Flush Kit with 1/6 HP Extra Strength Submersible Pump Tankless Water Heater Flush Kit with Quart/32 Fl Oz Descaling Solution Tankless Water Heater Flush Kit with Gallon/128 Fl Oz Descaling Solution Tankless Water Heater Descaling Solution, Quart, 32 Fl Oz Tankless Water Heater Descaling Solution, Gallon, 128 Fl Oz 1/6 HP Submersible Utility Pump Add to Cart Add to Cart Add to Cart Buying Options Add to Cart Buying Options Customer Reviews 4.3 out of 5 stars 38 4.4 out of 5 stars 34 4.6 out of 5 stars 30 4.6 out of 5 stars 17 4.8 out of 5 stars 7 4.3 out of 5 stars 19 Price $79.99$79.99 $99.99$99.99 $109.99$109.99 — no data $59.99$59.99 — no data Package Includes 5 gallon bucket + 1/6 HP Pump + 2 durable steel hoses 5 gallon bucket + 1/6 HP Pump + 2 durable steel hoses + Quart/32 fl oz descaler solution 5 gallon bucket + 1/6 HP Pump + 2 durable steel hoses + Gallon/128 fl oz descaler solution 32 Fl Oz liquid descaling solution 128 Fl Oz liquid descaling solution Submersible pump unit with 3 prong grounded cord + Adapter