This device works with all aquarium types, including freshwater and marine tanks. Key features include Water level readings are only taken when the Seneye device is in water, with no false readings.
I'm just cycling my tank right now - future mixed reef,
Purchased the Seneye Reef mostly as a PAR meter for my LED lights, but will use it to keep track of Ph and ammonia for the 30 day life of the "slide" that comes in the package.