Carbon Dioxide (CO2) Dosing

Carbon Dioxide (CO2) dosing offers a number of advantages over mineral acids such as sodium bisulphate and hydrochloric acid. It is becoming a more popular choice for pH control within the swimming pool. It works by being injected or diffused into the pool water. The CO2 forms a mild carbonic acid for pH control, it also forms natural bicarbonate which assists in the stabilisation of the pH level.

Under COSHH regulations a pool operator must carry out a risk assessment when selecting the chemicals to use in the pool. Firstly it is important to ascertain whether using an alternative chemical or process can eliminate the risk - CO2 does this. There is no possibility of accidental production of chlorine gas, as its not possible to mix CO2 with sodium or calcium hypochlorite (in liquid form) through spillage in bunds or operator error. Chlorine gas is a significant hazard in swimming pool installations.

• It is colourless, odorless and a non-flammable gas.
• Easy to handle and dose, it is only dangerous if released into a confined area.
• No special protective equipment is required.
• Deliveries are unlikely to result in emergencies because of spillages
• Where ventilation is good, CO2 does not require any special safety monitoring for leakages
• CO2 provides improved process control due to natural buffering action.
• Accurate control is easier as pH reduction is more gradual than with mineral acids.