Tunze Osmolator Universal 3155 Auto Top Off ATO

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Tunze

The TUNZE Osmolator 3155 is an automatic top off (ATO) system for marine and reef aquariums. The Osmolator – short for Osmotic Regulator – automatically adds freshwater to compensate for evaporation in your saltwater aquarium.

The high-tech German designed Osmolator uses a precision optical sensor to measure the water level. Water continuously evaporates from the aquarium, leaving the salts behind. This causes the salinity to increase. When you manually pour in water the salinity is suddenly decreased. This “salinity rollercoaster” stresses the fish and invertebrates by causing extreme fluctuations in osmotic pressure.

The Osmolator puts an end to this by continuously sensing the rate of evaporation (water level) and adding back the right amount of freshwater. This brings osmotic stability to the aquarium and keeps your sump and aquarium water at the right level.

Here’s what we really like about the Osmolator:

  • TUNZE invented the ATO and has been perfecting it for 30 years
  • Precision optical water sensor detects the slightest change in water level
  • Easy to install and adjust using the Magnetic Sensor Mount
  • Status lights display functions and sounds a warning in case of trouble
  • Built-in safety features prevent overfilling of the aquarium and shuts the system down
  • Comes ready to install – all you need is a reservoir or bucket

The Osmolator can be used on any aquarium, even freshwater tanks. It works when installed inside the aquarium on tanks without a sump. If you have a sump the sensor must be installed there since that is where the water level changes as it evaporates.

Features:

  • Complete kit with power supply, metering pump, hose and sensor mounting system.
  • The water level sensor has no moving parts to wear out and is not affected by suspended dirt, light or magnetic fields.
  • Optical sensor ignores gentle water movements caused by wave makers and circulation pumps.
  • An independent safety sensor with a separate power supply circuit and relay ensures reliable overflow protection.
  • A microprocessor monitors the water level in the reservoir and prevents the pump from running dry.
  • All functions are clearly displayed by colored LEDs and warning signals.
  • The Osmolator uses ultra-low voltage for complete safety.

For smaller aquariums, check out the Tunze Nano Osmolator 3152. If you need a container to hold your top off water, the Tunze Osmolator Storage Container 5002.25 is an ideal choice.

Specifications:

  • Metering pump flow rate based on pumping height: 3 feet:13.7gph, 5 feet:12.4gph, 6.5 feet: 7gph, Maximum pumping height: 7.22 feet
  • Magnetic Mount System: Maximum glass thickness ½ inch
  • For indoor use only
  • 2-year warranty

Product Manuals & Documentation

Tunze Osmolator Universal 3155 Auto Top Off ATO

Owner's Manual available for download in Adobe PDF file format

Manufacturer Info

Tunze
For forty-five years the name TUNZE® has been synonymous with aquariums. Many products and components which we have developed in the course of time are now standard features of aquarium technology today. This confidence in TUNZE is no coincidence. The company has remained true to its philosophy right from the beginning, researching water biotopes all over the world to develop components which enable natural water conditions in the closed environment of an aquarium. In the implementation of know-how, effectiveness and efficiency, TUNZE® takes the lead in environmental compatibility. Their motto is: quality and reliability. These values are upheld with well thought-out and precise tool making by highly qualified experts. The brand names of TUNZE® and Turbelle® meet the expectations of the seal of quality; Made in Germany. Many of the products shown in this catalogue are protected by national and international patents.


Warranty

Manufacturer`s Warranty: 2 years from date of purchase.

Ask a Question Earn 25 Points when you ask or answer a question
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9 Questions
Displaying questions 1-9
 
Q
Does anyone have this connected to a RedSea Max?
I just got into the hobby and have a RedSea Max E 260. (which I love so far) Looking for a good and reliable ATO. From research it looks like this is the best. Would I connect the sensors and water feed to the back sump or in the display tank? (I do not have the below sump upgrade - it's in the back of the tank) It's also 69 gallons and was in between this model and the nano version - any recommendations?
Asked : Feb 08, 2017
By : KF78, Saint Petersburg, FL
 
 
 
A
The Tunze Osmolator would be a great Automatic Top Off for this system. The top off line would enter the back of the tank in the filtration.
Answered : Feb 08, 2017
By : MD Tech
 
 
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Overall, others give this:

  • 4.5

112 Reviewers (93%) would recommend this

Overall Rating:

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5  Star
 79
4  Star
 21
3  Star
 6
2  Star
 2
1  Star
 4
 
5
5.0
Most recommended?
reviewerbadge
PROS
Complete adaptable solution
CONS
Let you know
REVIEW
Purchased because it was recommend by several
Talking heads on those tutorials. As a controls designer I could see the improved sensor capabilities and functionality along with the motor and all the parts to complete the project.
  • 1
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5
5.0
Could not be happier!
reviewerbadge
PROS
dual sensors w/ 10 minute fill stop in case failure
CONS
not fully a con - but runs & fills your tank for 20-30 seconds everytime you unplug/replug the device. its good to prime & test function, but may be something to fator if used in smaller tanks when doing water changes.
REVIEW
Tunze themselves were very fast to respond to questions I had. I have this set up on my 55gal reef (with a lip), and it actually keeps water above the lip line! I stickied some velcro (just to increase distance) on the glass, so my magnet could sit flush on half velcro / half plastic lip, which allo...Read More
  • 1
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5
5.0
Great product!

reviewerbadge
PROS
Quality product, reliable, consistent.
CONS
None
REVIEW
I added this along with a 5 gallon Trigger Systems crystal reservoir and it works seamlessly in my 54 gallon corner bowfront tank. Keeps my water and salinity levels consistent which keeps my tank happy.
  • 1
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2
2.0
Worked for a short while

reviewerbadge
REVIEW
When I first set this unit up, it worked great. However, one day about 2 months after I installed it I came home and my top off bucket was empty and my tank had an extra 3 gallons in it, provided by this ATO, which had malfunctioned and pumped until it could get no more RODI water and then finally ...Read More
Was this review helpful: Yes(4)No(1)
 
 
 
5
5.0
Best purchase ever

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REVIEW
i don't know why I waited so long to purchase this ATO. Super easy to install and get up and running. I have my 28G nano next to my bed and you can hear the pump kick in, but it's not that bad. But no more topping off with a jug. I do like the safety second sensor too.
  • 1
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1
1.0
3 separate tank all fail

reviewerbadge
REVIEW
This was my first ATO system. It was on my 600 gallon corner and set on my sump. Can't explain why but it unloaded 15 gallons of fresh water into my system. The optical failed as did the mechanical float. So because of the rave reviews I moved it to my 150 Q-tank. This system has a 25 gallon ATO, it...Read More
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3
3.0
Not a good design

reviewerbadge
REVIEW
Control box is very susceptible to humidity and moisture. Why would anyone design a controller that was susceptible to moisture when it is to be used around an aquarium? I've been through 2 controllers now, and now my current one is beeping failure alerts. And no, I didn't spill water on it. Als...Read More
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Overall, others give this:

  • 4.5

112 Reviewers (93%) would recommend this

Overall Rating:

download image
5  Star
 79
4  Star
 21
3  Star
 6
2  Star
 2
1  Star
 4
 

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