Nutrafin Aqua Plus - Tap Water Conditioner makes tap water safe for tropical fish by neutralizing chlorine, chloramine and undesirable metals. Aqua Plus contains U.S.-patented PHE (pure herbal extract), which effectively reduces stress and prevents inflammation and other undesirable conditions that can arise from scrapes, torn fins and abrasions.Aqua Plus is a complete tap water conditioner that improves aquatic environments for tropical fish.