The TETRApHix® advanced CO2 pH adjustment system is ideal for use in drinking water applications requiring CO2 addition for lime softening or recarbonization or the control of pH. The TETRApHix system uses a hollow fiber membrane to disperse carbon dioxide gas at the near molecular level into a side stream of water. The TETRApHix system uses industry standard horizontal or vertical bulk storage tanks with capacities ranging from 6 to 60 tons of onsite CO2. For smaller flows, dewars or a mini-bulk program with a local CO2 supplier are recommended. Each standard membrane unit is capable of dosing 22lbs/hr (200scfh). Multiple membrane units can be placed in parallel on a skid system for water treatment facilities with capacities greater than 40 mgd. This advanced system offers increased gas efficiency, low maintenance, reduced operational costs and a smaller footprint compared to conventional carbon dioxide pH adjustment systems. The unique feature contributing to the efficiency of TETRApHix is the gas delivery system and the gas-to-water interface. For more than six years, TETRApHix has proven to be a rugged carbon dioxide dosing system for drinking water facilities.