PoolRx contains different blends of minerals that continuously and effectively eliminates algae. These minerals immediately dissolve out of the cylinder and form a stable residual throughout the pool water for up to 6 months. The minerals eliminate the algae while freeing up low levels of chlorine to be more active and productive in the water. During the pools filtration cycle the minerals are rejuvenated every time they return and pass through the cylinder. PoolRx works synergistically with a constant low level of chlorine.