Nature2’s Express (Aboveground) allows pool owners looking to reduce their chlorine consumption while still maintaining a healthy pool with an effective self-contained sanitizer. Express installs on existing pool plumbing, using silver and copper compounds to sanitize your water, dramatically lowering the amount of chlorine your pool consumes. Lasting 6 months, this sanitizer canister will last practically one whole pool season, depending on where you live, and will save you significant time and money normally devoted to chlorine maintenance.