Starting in 2017 the EcoPur mineral cartridge system has become a standard component on all Master Spas. This innovative EcoPur cartridge allows for better water flow while charging your spa water with ions. Lasting for up to 6 months before replacements are needed, this technology is next level for Master Spas. The new system helps prevent algae growth, scale buildup and fungus from appearing in the water. These EcoPur Charge filters reduce your need for chemicals, protect your hot tubs plumbing, and helps prevent damage to your swimwear. Sanitizing your Master Spas hot tub has been taken to a whole new level of clean!