Hot Tub SERUM Maintenance liquid is an EPA registered bio film removal product. It is the only product in the spa industry that aids in the removal of bio-film according to the EPA. It is designed as a weekly addition to your customers sanitization regiment. The use Hot Tub SERUM Maintenance helps to destroy the bacteria that your customers current sanitizer can’t. It reaches down deep into the plumbing of the spa to help prevent the recurring buildup of sludge and bio-films that plagues every hot tub. The weekly use of Hot Tub SERUM Maintenance will also help to keep the water in the spa crystal clear, soft and clean.