The Tunze Osmolator Nano 3152 is the smaller version of the larger Osmolator 3155 from the German company released at Interzoo last week. This version is made specifically for smaller aquariums, around 50 gallons or less, providing what Tunze describes as “processor-based anti-overfill system.” What is nice about these water top off devices is that the Osmolator Nano will shut off after five minutes if the set water level has not been reached. Having a handy backup like this ensures that you don’t add to a problem by pumping in your entire top off reservoir.  The Osmolator Nano includes the control unit, low voltage (6V) pump, power adapter and magnet mount. It’s a ready to use out of the box, giving you a plug-and-play ATO for around $95 USD (€74.60 is the list price). Images after the break.