Dr. Tim's Aquatics NP-Active Pearls for Nutrient Reduction All Aquarium 15.21 fl. oz

A 100% biodegradable natural polymer that is pure with no fillers or chemicals. Pearls are a food source for beneficial bacteria that will remove nitrate and phosphate from the water as they grow keeping these nutrients away from algae. Helps keep away algae and cyanobacteria by removing excess nutrients resulting in better water quality and a clean aquarium.