This customer mounted his RAIN2 (tm) scrubber on a 1" grey pvc pipe on the right side, into which he added a 1" bulkhead to attach to the RAIN2 drain. The bottom of the grey pipe has holes for water to go out. You can't see what is holding the pipe up, but it is probably an end cap cemented to a plate.
The RAIN2 is fed water by flexible tubing attached to some pvc fittings, which feed into the 1" black waterfall pipe which you can't see inside the dome lid.