For starter, thanks for reading this.
I'm close to finishing my final year project with arduino. It basically is a wireless system to monitor the surrounding of the aquarium and warn the user in case something bad happens (too hot or too cold bla2) and also data logging for their research (for biotech lab).
But then they need another added notification, in case the aeration in the aquarium stops. I've googled around, and i know aeration can be controlled directly by arduino, but in my case, it is not possible since the LAB use Central Aeration System, which cannot be modified just to fit in 1 project.
So, here's the question, without touching the aeration system directly, how can i detect if the aeration has stopped in the aquarium? (btw, the device will be floating freely on top of the water in the aquarium, half-submerged). I'm thinking along the line of IR sensor, sound detector and vibration sensor. IR would be useless once the device floats too far from the aeration bubble and sound detector, well too many irregularity needs to be considered. Vibration sensor seems close to what i want but then I doubt it would work underwater.
Any suggestion, dear arduino-ers?