No need to drain the pool due to high cyanuric acid when you have the 4-pack of Bio-Active Cyanuric Acid Reducer Powder for Swimming Pools. This acid reducer naturally reduces your pool's acid levels up to 50-percent. Eliminate chlorine-lock due to high cyanuric acid levels, and allow sanitizers to effectively clean the pool with this acid reducer powder. The powder is non-allergenic, non-polluting, and leaves no residue, giving you peace-of-mind the pool is safe and clean. Advanced biocatalyst technology reduces acid by disintegrating it on a molecular level without a harsh smell, and causes no adverse effects on the pool.