Could you add an elbow or two to the top to give you a place to hang a bag? Or do the gate valve mod, you don't have to buy the ASM kit you can get the parts yourself at somewhere like Western Pump.
http://www.asmskimmer.com/mod1.htm
Like they say the PVC gate valve is the hardest to find but I'm using a slice gate valve on my CS8-3 and it's working fine.
