My pond has two parts:
- A normal pond for plants and a few goldfish.
- A natural filter, gravel, sand and plants to filter out any nutrients and poo produced by the goldfish.
This is an excellent job for the Arduino board, pump and air will switch 220VAC and three AD ports will be used to sense the temperature.
- At the surface of the pond.
- One meter in the air.
- In the filter.
The whole program needs to be fuzzy and datacollecting just for fun and usage of the USB / Serial port.