Tunze osmolator 3155
 

Is this the best ATO for my nano? Or is the Tunze Nano sufficient. Im torn not by price as much as whether or not the 3155 is over kill.

Well the answer in my opinion is... it depends. There are a few factors that go into making the best choice for your particular application. The main difference that you are paying for is that the Tunze Osmolator 3155 utilizes an optical sensor for detecting changes in the water level to determine whether or not to activate the pump for refill. It is backed by a secondary float switch to prevent overflows to your aquarium. The Tunze Osmolator Nano 3152 only using a single float switch for it's primary detection method. Some individuals have experienced float switches like this becoming stuck which continues to delivery top off water which could cause a flood. The Tunze Osmolator Nano 3152 combats this by only filling up 0.75 gallons of water per top of activation. So if you require more water than this to top off that is going to be a problem. So it is recommended for aquariums no larger than 55 gallons. There are more items that I can list to compare the models. But what are your specific concerns if any and maybe I can help answer them.

One of the things I hate about the 3155, specially for a nano, anytime the power goes out it starts the pump and dumpos about a 1/3C of water into the tank. It's basically to prime the pump.



The nano I had on my biocube never did this, but I did have a float stick in the down position and dumped my entire 5G topoff container into the tank causing it to overflow.



I then checked that specific float during my weekly WC regimen.

you can change the amount of water (time) being pulled by opening up the controller case and turning a little knob for the nano. However, I hate the nano with a passion. I have had 3 of them (yeah, I know dummy me) and all of them have failed me in one way or another. They had a controller board issue last year and updated the board so there are two different versions out. The only way to tell is by the MFG date. My 3155 has never failed me in the 5 years I have owned it.

I've had very bad luck with the 3155 failing on me, honestly the TUNZE ATO systems are not the best IMO...

While I'm certainly not discounting your experience with the unit, there is a reason they are the number 1 ATO solution sold.

Most people have issues with the pump failing. However, when reaching out to tunze when my pump died, they told me that their pumps last 2-3 years before being replaced. They sent me a replacement pump for cost and also updated the software for free. Easy to deal with. I have the tunze nano ATO and it serves my 28g well

If you have the Apex controller you can change the way the 3155 works. I have mine set to not turn on in case of power failure. I think I found the rationale and programming when I did a google search and found it here on RC.

I use the Smart ATO works great and is perfect for a nano IMO. One small water line sensor that detects if your tank needs water or not. Small but powerful pump that I keep in the bottom of my cabinet that kicks on and feeds the back chamber of my AIO 25G Lagoon. I havent had it fail on me and good extra selling point is that it beeps when something is wrong or it needs to be reset or your fresh top off water is out.

I've had a positive experience with the 3155 on my 43 gallon system. I like the piece of mind of having an optical sensor for the main sensor and a float switch for the emergency cut off sensor.

Buy the classic full sized Osmolator, they are extremely reliable. Most of the problems people have are user error. I don't care for the Nano. Mine overfilled a few times for no apparent reason so I don't trust it. It's in a box I the cellar.