Pool first aid combines powerful concentrated enzymes with an organic Clarifier that is ideal for big clean ups. Gets rid of scum-lines, waterline ring, cloudy water, clogged filters and chemical odors with no scrubbing. Pool First Aid will quickly free clogged filters of oils and organic build-up... in most cases no backwashing is required. Use 1 cap full per 2,000 gallons of water. Use as needed.