If you connect the Farbwerk via USB to your PC, then you can control it over the "Farbwerk"-Tab in the Aquasuite. If you add the Aquabus connection, you can control the Farbwerk with the controller Tab on the Aquaero. Then you have to set the outputs on the four Farbwerk channels to "Aquabus".
You could use an Y-splitter or you could connect the Poweradjust to the second Aquabus port on the Farbwerk,
Aquaero > Farbwerk > Poweradjust
When you control it with the Aquaero you would also have the advantage to use the different Profiles to turn the Lights completly off easily