The Tunze Osmolator 3 Nano is the smaller version of the Osmolator 3 Auto Top-Off Device. It’s suitable for aquariums of up to 250 liters (66 US gal.), sticks to 12mm thick glass, and can be used on either sumped or sump-less reef and freshwater aquariums.
You can’t talk about ATOs without mentioning Tunze, because company founder Norbert Tunze invented the first one way back in the 1980s, and the Osmolator brand name has been synonymous with ATOs ever since.
The new Nano shares almost all the design and build attributes of the Osmolator 3, being built in Germany and boasting a no-quibble five-year warranty. That’s fuss-free topping off until 2030!
The Osmolator 3 nano has just one level sensor, versus the second safety sensor on its bigger brother, but pretty much every other aspect is the same and this should be at the top of the list of anyone shopping for a junior-sized ATO. For a hand-made product that’s built in Germany, it’s well priced too.
I feel they have ruined this by using a white cable to the sensor. For me, it’s a negative as the sensor would need to go in the tank so I would want a black cable to make it less obvious. The full non nano version is black so not sure whey they didn’t do this one the same.