My school is working on a multi year project to create a water condition monitor with remote access, this would be used in a marine environment when diving or monitoring water life.
So far we have built Raspberry Pi’s to store temperature using a Waterproof DS18B20 Digital temperature sensor. We then convert the MySQL data to a JSON web file and then can access the data remotely. I even made an iOS app to display the temperatures collected.
Our next step would be to connect all our aquariums (23) to as few Pi’s as we can and collect the data. I have been informed that we can have 75 of the sensors in 1-wire communication but we may have issues with distances etc. This seems to be going fine.
Also we would like to collect pH and Salinity. Does anyone have suggestions as to the best sensors that would allow us to collect readings easily with Raspberry Pi’s.