Hot Tub Serum Total CleanseThe Hot Tub Serum Total Cleanse is a biofilm purge product that will efficiently remove the bacterial slime from your spa's plumbing and jets. To ensure that sanitizer products do not decay faster from hidden biofilm in the plumbing, it is suggested that this product is used every 4 6 months depending on the type of spa. This is compatible with all spa sanitation systems including chlorine, bromine, salt, and biguanide.