Hawaiian Isles Water undergoes a rigorous seven-stage purification process.

Stage 1: A standard practice in the industry, Hawaiian Isles water is processed through a sodium chloride water softener. This softens the water prior to filtration.

Stage 2: Hydrocarbon-based organic compounds are removed in a pressure-based, activated charcoal tower.

Stage 3: Inorganic compounds (minerals) are removed via a pressurized multi-stage reverse osmosis system.

Stage 4: The water is filtered through six successive spool and bag filters ranging in size from 15 to 0.2 microns. This constant reduction in diameter of the membranes through which the water molecules pass removes most of the compounds and bacteria and other life forms because they cannot pass through the membranes. This process yields less than one gallon of water for every two gallons processed.

Stage 5: The water is pumped through an ultraviolet light processor which kills any remaining bacteria and sterilizes the water.

Stage 6: The water is filtered again to remove any dead bacteria, and then is pumped into a sterile stainless steel ozone tank.

Stage 7: During storage in the sterile tank, an ozone generator pumps bubbles of ozone through the tank, further sterilizing the water to ensure its purity when bottled.