Spa MarvelSpa Marvel Water Treatment & Conditioner (Spa Marvel) is an environmentally friendly, enzyme based hot tub water treatment product that can reduce and eliminate the need for many of the chemicals used in traditional hot tub water treatment. Benefits of using Spa Marvel No more scum lines. No more chemical hassles. No more hot tub rash. Gentle to skin and hair. Conditions water for sensitive skin. People with eczema and psoriasis love using Spa Marvel