When there is no pressure of ozone, and the water does not bubble much at 4" in a glass of water, it may be time to change the air pump for the Aqua-8 Ozone Generator. Use only Official A2Z Ozone parts for your Aqua-8 ozonizer. Check your power to make sure you have power. Get your technician to repair the unit. Choose your voltage for the ozonator that you need based on your electricity.