Some feedback/pictures –
First, thanks very much for your support (I needed a part and it arrived very quickly), and your manual is excellent.
I installed one unit on the apartment to raise the PH – Results were immediate, just need to do some fine adjustment.
The second unit was installed in the house water system after the filter. Note the flash water heater – We had to replace the (expensive) heat exchanger as it corroded in only 8 years due to low PH (not surprising! There’s a lesson here).
I used Flexogen ½” garden hose for the drain hose, along with a couple of ½” brass fittings, worked out great.