Make sure the Raspberry Pi's power supply is generously dimensioned. If the Aquaero power supply fails, the Aquaero draws its 5V power from the USB port of the Raspberry. If the power supply is too weak, the Raspberry Pi may become unstable.
The Raspberry Pi 1 has stability issues with the USB port, maybe due to hardware or driver problems. Once in a while, the USB connection to the Aquaero is lost, and must be re-established by restarting the
pyqdservice or by a reboot.
I don't know about the state of Rasperry Pi 2. Your feedback is welcome.
The Raspberry Pi 3 has no USB issues.