Sledgehammer is a rinsing agent that grabs on to the nutrient/salts so it takes a lot less water to perform a flush. I slowly pour in the water with sledgehammer and let it sit 30min to an hour. Then follow up with plain ph’d water (usually 2 gallons) until my ppm’s are close to the water Ppm’s that’s being put into the soil. Once the Ppm’s are right, go back with a gallon of your nutrient solution