I tested the system with a 9V, 1.6A supply I found. The pump is much quieter with water inside. While testing it with 12V, 1A supply I got voltage drops, enough to restart the ESP, so I would suggest 1.5 to 2A minimum.
No more tedious lifting of the watering can for me, or remembering to water the plants, or remembering I have plants. What is more soothing than listening to a robot take care of your plants anyway...
The system can be made small enough to be strategically hidden and the self-priming pump allows to have the water reserve anywhere. The pump will not pump the water backwards and holds it in the tube while not powered, so it only needs to be primed once.
I would like to have some more features, such as a water flow meter (in order to define the water quantity to be delivered instead of the pump timeout) and a reserve water level indicator (that could alert me in case water runs out), these will be integrated as I receive the parts from eBay.