Pool SERUM is a complete, easy to use and effective product that will help to remove and prevent the buildup of bacteria in your filter. It will also help to stop the build up of mold and slime in your pool especially black mold, green algae, yellow mustard algae and pink slime found in biguanide pools. Using Pool Serum as a preventative monthly application will help to keep your pool running clean and clear. It replaces the need for algaecides and clarifiers. It will also help the salt generator last longer and run more effectively. One jar added monthly treats up to a 18,000 gallon pool.