The degassing tower (also known as a carbon removal tower or stripping tower) is a core water treatment unit in industrial Recirculating Aquaculture Systems (RAS).
It relies on countercurrent gas-liquid contact to remove dissolved gases—such as excess carbon dioxide, nitrogen, residual ozone, and hydrogen sulfide—from the water body, stabilizing water quality and protecting aquatic life.
When CO₂ dissolves in water, it forms carbonic acid, directly lowering alkalinity and pH while accelerating water acidification. This can lead to acidosis, reduced feeding in fish and shrimp, lower immunity, stunted growth, and even severe asphyxiation or mortality. By discharging CO₂ from the water, the degassing tower stabilizes pH levels and significantly reduces the operational cost of adding pH regulators like baking soda and lime.
Typically, maintaining dissolved CO₂ levels below 5 mg/L satisfies the safety threshold required for high-density aquaculture.
