Sorry about the link - thought I had the switch in my copy buffer.
To connect the CPR to a PH use the venturi hole on the PH. So instead of the tube going to air pump - attach it to the venturi hole by the directional output flow.
In plain English
- right by where the water comes out of a PH you should see a hole (might be capped) but you can attach the hose there.
I use these PHs - if you look right by the "fan"/ output of the PH you will see the place where you need to attach it.
Hope I made myself clear -if not just holler. I'll try and explain it another way.
EDIT: if you need to buy a new PH or are concidering replacing the pumps with PHs get something around 200-250 GPH
. Should work wonders.