Using your pool net, skim as much leaves and debris from the pool.
Lower chlorine to 1.0 ppm
Lower your chlorine reading to less than 1.0 ppm by either using chlorine neutralizer or abstaining from adding your sanitizer for a few days.
Add Pool Stain Treat®
Add one (1) bottle of Pool Stain Treat® per 20,000 gallons of pool water.
After 5-10 minutes brush the walls of the pool. One good brush over the wall should be fine.