Germans have been inventing and developing high-end, high-quality aquarium equipment for decades. Tunze is one of Germany’s leading aquarium product manufacturers, with 54 years of experience creating and producing aquarium solutions that are now standard in many hobbyists’ tanks.

The first-rate design, dependability and reputation of Tunze are why I decided to outfit my aquarium with a Tunze auto top off device.

The Tunze Nano Osmolator 3152 was a perfect fit for my Innovative Marine 38 Gallon Mini Nuvo Aquarium, so I wanted to share my feelings about this ATO system in the event you’ve been considering one for your own tank.

Unlike some other auto top-off systems on the market, the Tunze Nano ATO includes everything you need to get up-and-running right out of the box. Here’s a quick rundown of what’s included:

  • The control unit
  • A float valve with protective cover
  • A magnetic mount
  • 3 mm flexible tubing
  • Mounting clips
  • A 6 volt pump
  • Power adapter
  • Instructions (in 6 different languages)

Installing the Tunze Nano ATO is simple thanks to easy, step-by-step instructions. Since my aquarium is larger than 26 gallons, I switched the jumper on the controller so the pump will automatically stop after three 3 minutes instead of 1.8 minutes. This switch is in the controller casing and can be adjusted by moving a plastic piece to a different metal prong.

To set up the auto top-off system, slide the protective cover over the float valve and attach the float to one of the magnetic mounts. This prevents livestock, like snails, from altering the float valve. After sticking the protective rubber feet to the magnets, place the float valve as high in the pump chamber as you wish. I have mine approximately 3” below where the water overflows into my pump column to prevent micro bubbles from reaching my pump.

Next, plug the pump wires into the controller using the terminals by sliding the wire into the plastic hole, clamping down and squeezing it. I taped the controller to the inside side of my stand so that its motherboard will always stay dry.

Insert the hose into the pump. Then attach the hose to your aquarium using the mounting clip so the water will pour into your tank. Last but not least, place the pump into a bucket of fresh top-off water. You are now ready to plug the power cord into the outlet and have a working auto top-off system!

The system has been running great. However, I did experience one instance where it did not work properly. I arrived home after a weekend out of town to discover the pump almost running dry. I had plenty of water in my reservoir bucket, so I tried pushing the float valve up and down. It did not turn on, so I unplugged the system from the wall outlet, plugged it back in and it kicked back on.

I decided to contact Tunze for advice. They theorized that because my tank glass isn’t very thick (8 mm), the magnetic field from the mount might be messing with the sensor in the float valve. I cut a square out of a koozie (a mouse pad would also work) and placed it between the glass and the magnet on the back. I haven’t had a problem since and it’s been 2 months since the mishap.

Tunze’s customer support team is amazing! They will help you troubleshoot or even repair/replace equipment if you need it.

The Tunze Nano Osmolator is another amazing Tunze product and I would recommend it to anyone with a nano-sized aquarium. If you are shopping for a high-end auto top-off system that is reliable and backed by world-class customer support, look no further than the Tunze Nano Osmolator 3152.