is a disposable pouch that makes metal removal and stain prevention easy and convenient. CuLator works in your fresh or salt water spa to eliminate metals and prevent stains for up to 6 months. Metal particles bind to the polymers in the pouch and cannot escape so your spa stays crystal clear and stain free. Leave the SpaPak in your reservoir continually, or use it when you fill your spa (let it work for a day or two then just rinse, dry, and reuse). Each SpaPak comes with a CuLator GatorEgg protector.