Biodegradable Organic Concentrated Formula: Contains 1 Gallon descaling solution, Mix the appropriate ratio of water. For Descaling tankless water heaters, pour 1 quart (1/4 gal) descaler into a bucket containing 1 gal water. Works with most tankless water heaters such as Rinnai, Bosch, Noritz, Rheem, Takagi, Tempra, Navien, Ecosmart, Stiebel, Eccotemp, Atmor, Trutankless, Marey Power, and others. Our cleaning solution removes scale deposits from tankless water heaters, which helps improve its efficiency and lifespan. Its citric acid based, and solvent free formula is safe for use with most metals, PVC, Rubber and ABS plastic hoses and materials. It's also non corrosive and safe for potable water systems. Step by Step Tutorials: Follow along with other DIY-ers and clear instructions on our Drainx Youtube Channel - featuring a step by step guide on how to descale your tankless water heater at home using Drainx products. To ensure that a water heater continues to work at an optimum level, it is necessary to descale the appliance. This will mean removing the deposits that can build up from the use of hard water. Hard water is water that has high mineral content. 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. Tankless Water Heater Descaling Solution helps maintain and extend the lifespan of your tankless water heater.