Keep your aquarium clean and healthy with API Stress Zyme Aquarium Cleaning Solution in a generous 1.89L size. This potent formula contains beneficial bacteria that efficiently break down organic waste, reducing the need for manual cleaning and water changes. Its large volume provides long-lasting treatment for larger aquariums, ensuring a pristine aquatic environment for your fish and plants. Provides a large volume of beneficial bacteria for treating commercial or large aquarium setups Helps reduce maintenance and improve water quality, promoting a healthier environment for fish and plants Easy-to-use liquid formula, simply add the appropriate amount to the aquarium as directed to boost biological filtration and maintain optimal water conditions