How do I get squid to work with OpenVPN clients

[22213w]

Hi,

I have all my PC connect to OpenVPN via AirVPN. All is working well.  So I decided I want to monitor the traffic on my LAN with Squid and LightSquid.  The problem I am having is all my PC is on OpenVPN with a public address from AirVPN. When I enable Squid and Allow users on interface and Transparent HTTP proxy it turns all of my PC's Back to my ISP public IP address when I do a www.whatismyipaddress.com.  Squid and LightSquid works but I loose my OpenVPN connection to my VPN provider…..

I would like to monitor traffic to watch over my kids usage and block sites they are not allow to use.  Any other solutions with OpenVPN

any help please