[mdoms]

I'm building a prototype water level sensor for my 30,000 litre tanks. Ultrasonic sensor to find the water level and an embedded web server to surface it (in my case it's near enough to my house to use my home Wifi - I'm publishing it as a Prometheus scrape target, but could easily be a website). When it's a bit more polished I will ask my neighbours if they're interested (we're all on tank water). I don't plan to make a profit but it would expand my skillset.

[doanerock]

If you are just doing this for fun then have fun. If you want to commercialize it at all you most likely want it to communicate via MQTT not a scrape target. MQTT has much wider support for additional intergenerations.

[Trex_Egg]

Does the water vapours fog up the ultrasonic sensor. If not what ultrasonic sensor you are using?