Yes, you can connect the second PA2 to the first one which is connected to the aquaero. But before setting it up this way you have to change the aquabus ID of one PA2 controller and maybe you also have to update the firmware. To do this you connect
one of them via USB, run the
aquasuite 4.72.00 and update the firmware if the device does not have the latest version. Do this again with the second PA2 controller but this time you also change its aquabus ID from 50 to 51 in the aquasuite. Save the settings to the controller.
Only this way the aquaero can differ between both controllers.