Hint:

Not using 2 of 6 zones too due to yardwork. I just changed the schedule and removed the zones from the schedule. The 2 unused zones are not watered automatically temporarily.  Note: I did not remove the unused zones from the system and did not disable them. This allows me to test the zones manually by manual watering the zones on my phone on the spot. It helped me very well adjusting the new sprinkler heads without walking back and forth to the system / taps all the time. 

Not sure how to connect a separate rain gauge. I saw Nerto offers separate WiFi sensors too that measure ground humidity. My guess is that this is as good as a rainfall measurement.

Reading about your configuration maybe you can help me. I have just installed a Sprite too and I am trying to set Wunderground as provider in the app. I have an Alecto WS-5500 connected to Wunderground. When I select Wunderground as provider the app asks for my weather station ID which I have (ISTWIL10). But the app seems not to accept it as a valid ID. Do you have any suggestions?

Thanks.

Perry