Hello,
I have a Lelit Mara X Coffee Maschine which I made smart with a simple smart socket. I now wanna measure the level in the water tank and get notified when it’s almost empty.
Does someone know a good sensor for this which is able to connect to home assistant easily?
Max
You could use one of these, attach cables to the screws in the back and have those cables down the water tank. Empty tank = dry sensor. Water Leak Sensor - Aqara
I think there is not enough space to fit the sensor. I have to take out the tank from time to time.
I had this sensor inside the water. But after a while the battery leaked. I guess it was too warm for the sensor. It should be water resistant normally.
You don’t need the sensor inside the tank, just the cables.
As I said. Where should I put it, when I have to take out the tank occasionally?
I would not know, that is for you to figure out 
You probably don’t get much more placement-friendly devices than that though.
In my experience it’s very difficult to get right. If you have the wires close to each other or close to the side of the tank, water droplets tend to stick to the wire due to surface tension and the sensor doesn’t trigger.
I now use a float sensor (stuck against the side of the tank towards the bottom) which works very reliably.
You can stick a sensor on the inside of the tank, although that would mean you cannot fully fill it to prevent the sensor from being submerged and triggering when the tank is full.
My Alex Duetto has a stupid low water cutoff that powers the whole machine down !!
My low water alarm is not smart but uses the existing floating magnet in the tank to close a reed relay that is stuck to the outside of the tank a bit before the factory circuit kicks in and that is connected to a coin cell and piezo buzzer.
Yeah you probably right.
I’ll try that. 
@robertklep How did you fixate the sensor in your tank? Just using gaffer?
