Disconnect the tubing for the tank valve. Dump many of the water out with the tank. Then check the air force as proven over. Modify towards the proposed force. Then reinstall the tank and tubing and turn around the water. Customer support might not be equipped that may help http://travisvw4g7.yomoblog.com/580281/the-definitive-guide-to-how-to-install-a-water-system