Purified water grows healthier plants. Purify tap water with an Osmosis filter, which removes harmful minerals, chlorine, & stabilizes ph. Using an osmosis filter in hydroponics system is ideal for healthy, lush, and high yield plants. If you are using beneficial biology in your system, you must remove the chlorine. Chlorine will kill you beneficial biology. A large filter for your home will also benefit your landscape plants & turf. Also, with the harmful mineral removed your pH level will stay buffered, and not swing base or acidic. Remember hydroponics systems need a pH at 5.5-6, and soil gardens at 6.5-7.