Product was successfully added to your shopping cart.

Call us now Toll free : (888) 840-1146
0 $ 0.00

You have no items in your shopping cart.


Tunze Universal Osmolator Automatic Water Top-Off - 3155

Tunze Universal Osmolator Automatic Water Top-Off - 3155


Convenient automatic replacement of evaporated water - with a safety mechanism.


Availability: In stock

$ 259.95

Product Questions

Is there a warrentee on this unit?
Product Description


    TUNZE Aquarientechnik has developed a new generation of osmotic regulators with static and compact sensors in IR technology for constant water level regulation in freshwater and saltwater aquariums. It ensures osmotic stability in freshwater and saltwater aquariums by precisely and regularly compensating the evaporated water.

    The precise water level is ensured by a non-wearing optical sensor and a transistor switch without any moving parts. This sensor is insensitive to soiling, light or magnetic fields. Its "automatic eye" recognises the water level precisely, even small waves or level variations cannot irritate the unit.

    An independent safety sensor with a separate power supply circuit and relay control ensures reliable overflow protection.

    An electronic time controller and current limiter for the pump connected result in a higher operational safety. This unit protects the metering pump against running dry and reports an empty storage container.

    All functions are clearly displayed by LEDs; safety messages are also indicated by acoustic signals.

    Comes ready for mounting. The sensors can be stuck to glass surfaces or can be fitted directly to the edge of the tank.

    Warranty: 24 months.

Additional Information

    Additional Information

    Display request for quote No
    1. Great Product Review by Cano

      After 2 smart aqua micro ato sensor failures I felt all sensor style ato were crap. I needed an ato quick and decided to give this a try. What a great ato!! Was out of town for a week and came home to no water overflow mess. Have this on my 32biocube in the return chamber. It keeps my Tunze 9001 skimmer working great. Highly recommend this ato! (Posted on 3/2/2018)

    2. Great ATO with triple safety Review by Vincent

      I've used the Nano Osmolator from Tunze for years but the unit eventually failed in the "on" position, creating a small flood on the floor. I purchased this to replace it after seeing many good reviews. It's a bit pricey but it's worth it. I tested all three safety measures and they work great. The audible alarm when either of the secondary safety controls engages is very helpful (and would have saved me from the flooding). I love how small the mounting bracket is. It fit perfectly in the back of my RSM 130D. (Posted on 11/25/2017)

    3. Why did I wait so long! Review by Adam

      Great product. I don't know why I waited to long to get this ATO. No more hauling partial buckets of water every day to top up the sump.

      My order was mailed out and I received it in short order. It was super easy to set up, and I had it working in no time.

      It keeps my water level right where I want it. It is super easy to adjust the water level.

      The price may deter some people, but TRUST ME, you will be thankful that you spent the money to buy this awesome quality product!

      Adam from Alberta (Posted on 10/30/2017)

    4. Great Product Review by Michael

      Noticed that this guy hasn't been reviewed yet, which is crazy because it's a great product.

      Initially I cheaped out on a home-made style auto top off with a float valve and and small pump, big mistake. It had no safeties built in and well, kind of put me in a "position for disaster"

      I then got this one and swapped out the other about 4 years ago. I've been using the same unit for the 4 years non-stop with minimal maintenance. It works flawlessly, has alarms, and a backup float valve to prevent flooding.

      4 years on and I'll be buying another for a second system. The only issue I've had after 4 years is the pump is starting to make a whirring noise.

      If you need and ATO, this is the one. (Posted on 1/4/2017)

    Write Your Own Review

    Only registered users can write reviews. Please, log in or register


    No Available Download Links