- Osmolator Nano 3152 Auto Top Off - Tunze
The Tunze Osmolator Nano 3152 Auto Top Off is designed for smaller tanks, approximately 50 gallons and under. One of the safest ATO’s available. Utilizes a single sensor to monitor water levels and a controller that protects against overdosing.
- Magnetic holder for sensors up to 10mm or .39".
- Max Head Height: 7.0 ft
Introducing the little brother to the Tunze Osmolator, one of the industry’s most trusted automatic water top-off device and BRS Recommended. Designed specifically for smaller aquariums, roughly 50 gallons and under, the Osmolator Nano 3152 is a slimmed down version of the full sized 3155. It includes a processor-based anti-overfill system which turns the pump off if after five minutes of filling the level has still not been reached. The Osmolator Nano includes the control unit, low voltage (6V) pump, power adapter, 3m hose, magnet mount and protective cover.
Junk By Brian on 1/15/2020Brian wouldn't recommend this product to a friendFailed twice within the first 2 weeks of install. I should have taken all of the terrible reviews into consideration. It drained my reservoir dry even though the float was literally underwater. Terrible engineering.
Failed twice in 1st month By CadillacCorals on 1/4/2020CadillacCorals wouldn't recommend this product to a friendThis is my second one. I don’t know why I spent so much money on this junk. Should have 1 star across the board. Failed twice in the first month, both in the on position. Overflowed the DT, thank goodness it was only 1/2 gallon. Unfortunately it was in my 13.5gal so adding 1/2 a gallon of rodi water was no bueno. Wish I could return it.
Do not purchase this ATO! By Liam on 11/26/2019Liam wouldn't recommend this product to a friendAs previously alluded to in an earlier review of mine, this product is not safe. Failed within a few days of install in the on position. Loud. Very poor quality. Really disappointed in this product and especially at its price point. BRS please pull this from your site.
Not reliable By Chris on 8/11/2019Chris wouldn't recommend this product to a friendJust like the other reviews. Not reliable. Stop start. Now broken less than 6 months in. Not sure how ranking is too hight.
Do not purchase! By Liam on 7/1/2019Liam wouldn't recommend this product to a friendDisappointing Tunze product. Failed twice in on position. Very loud pump. Consider a different ATO—the nano is borderline dangerous. No failsafes. Single point of failure with single float switch. Really wanted to like this.
Unreliable By Brian on 6/6/2019Brian wouldn't recommend this product to a friendI bought 2 of these units a couple of months apart. The first one has been fine. The second one didn't work (float switch problem) right out of the box. BRS shipped me a new one. That one worked weill for afew weeks then became a constant source of problems. The float switch or something causes it to overfill then shut down on the 3 minute protection feature. So my salinity in a 32 gallon tank plummets then skyrockets unless I check it every day. I have tried everything. The float switch is spotless clean and will work when you test it (sometimes) but then a day or two later the same thing happens. It is far easier and better for both me and my corals that I just manually top off. Bottome line is that 67% failure rate is unacceptable. I am very dissapointed... so much for German engineering. Don't waste a hundred bucks on junk like I did.
Stops working randomly By Richard on 5/11/2019Richard wouldn't recommend this product to a friendThis is a piece of garbage. While I was on vacation It stopped working and and the water level in my 12 gal dropped low enough to burn up both of my pumps!!! I contacted Tunze after I first got it for the random working conditions. They said place a barrier between the magnet and float switch because of the thin glass. I did this and it helped the pump to work 60% of the time. Do not waste your money on this system! I have had this less than6 month and it's been nothing but trouble. I wish I could return it and buy something else.
ALWAYS STOPS WORKING! By conaway on 5/6/2019conaway wouldn't recommend this product to a friendA huge waste of money from the start of having them we had to keep unplugging them and plugging them back into work! we bought them last june and never again will we buy these ever again cause way to much headache the main reason im writing this review now is cause i just walked into my living room and low and behold the freaking thing stopped working once again this should not have to be a daily thing!
I wanted to love this. By jonathan on 3/16/2019jonathan wouldn't recommend this product to a friendI bought this back in July of 2018. Things were great until a few months ago. Unit worked flawlessly, until it didn’t. I hit the forums and tried everything the owner suggested to people having the same “failure to start” the pump issues. I thought it was the safety timer. Switched the jumper to extend the pump time. Nope. Now this ato will not work until I reset the system. I even saw on the forums that the main distributor was suggesting an “update” to the control unit in 2017 that fixed this issue. I bought mine in 2018. I have reached out to Tunze America and am awaiting a response. I really wanted to love this ato, but it’s not anything I would recommend to reefers that care about the quality of the devices they use to keep a tank thriving.
Would not recommend. By Michael on 1/22/2019Michael wouldn't recommend this product to a friendI've had this ATO for almost a year, and though it does it's job for the most part. It is also sure to malfunction monthly (seemingly always when out of town) causing either the water level to drop drastically or flooding the tank.
Failed twice within a week By David on 1/12/2019David wouldn't recommend this product to a friendHad it set up for a week and it failed twice both ways. First time the float switch got stuck in the up position and it didn’t do it’s job. Second time float switch got stuck in the down position and it overfilled but the time limit saved it from overflowing the tank, at least that worked!
Good ATO, but not well made By Joe on 1/2/2019Joe would recommend this product to a friendI started buying the more expensive European/Japanese products for my tank because I thought they would be better made/durable/reliable, but the sensor housing/shield broke while disabling. I was trying to clean the sensor and the tabs that holding the housing on snapped off with little force. The housing holds the sensor on to the magnet, so now my ATO sensor is dangling in my sump while I await a replacement part. What a hassle!
What's the main differences between the nano and the 3155? Also, would be possible to upgrade in the future without having to buy the whole thing?
The nano osmolator is just a simple float switch and that is it. The 3155 has the dual level control with the optical eye for primary control and the float switch emergency backup. The 3155 offers superior redundancy.
It would not be possible to upgrade, they are entirely different units.
What if you dont have a sump, can you put the controllers directly in the aquarium?
Will this work on a 70 gallon setup!
While it may be sufficient for a tank of that size, depending on head height the pump has to push against, it does have more limited capacity and safeties set up for small tanks, so we don't generally recommend this one for tanks over 50 gallons.
Have a great day!
Can you increase/decrease the pump flow like the 3155?
Just to be safe what are the pump dimensions.
Thank you for reaching out to us. The pump is approximately 4"x2".
Please let us know if you need anything further and take care!
Other than the reservoir, What else is needed for this kit? Also, what is the maximum head height of the pump? Thanks !
Other then the container the kit really comes with everything you need to get started. The pump has a max head height of about 7ft.
How much travel between on and off with this sensor? 1/3"/ 1/2" etc.?
The distance between the float being triggered and off is between 1/4" to 1/3" Feel free to let us know if you have any further questions!
I recently purchased one of these and think I will LOVE it but have a question. Each time I have gone to check on it, it seems the relay/sensor (whatever we call it) has shifted slightly so it is no longer sitting level. This is help on with the magnets, so am curious as to why this is happening or what I can do to stop it!
You can always try implementing a large magnet to ensure the hold is stronger. Other than that, there are some more permanent applications such as small amount of super glue. In any case your best bet will be to contact TUNZE and see if they have any tips or tricks.
Tunze – 512-833-7546 firstname.lastname@example.org
If this pump were to break could you use the Apex Neptune PMUP as a replacement for this system?
I'm going to be using the solenoid option with the 3155. Can i purchase it with out the pump it comes with? seam like a waste of money if I'm not going to be able to use it.
I was curious if this auto top off will work for my Innovative Marine NUVO 10. Would the water get too salty by the time the ATO kicks on?
That is a valid concern and if you are keeping SPS in the 10 gallon then we would suggest looking into the Osmolator 3155, however for most fish, and other corals like softies and LPS the Osmolator nano will work just fine. Since the return pump compartment is much smaller than larger tanks, when water evaporates it will move the water level pretty quickly and activate the float switch which is pretty sensitive.
Does this model have an optical sensor such as the one in the larger model?
Hey BRS - do you know if the sensor pod will fit in the back of a Coral life Biocube? Im running no hood and would like to add this since im loosing about a gallon a day due to my A/C here in sunny south florida. Reading the previous question, is the same true for the 3155?
They will both be able to fit back there.
Why can't this model be used on a larger system?
The unit is not suited to large aquariums because it has a timer based cut off so the pump will only run for a short period of time. Using it with a large tank can result in the the pump turning off before its finished replacing the evaporation.