Good for what I needed By Eric on 2/23/2015
Eric would recommend this product to a friend
This is my first auto top off and it is working fine for what I have. The size is good and the pump is running great so far. I have only been using it about a week with only one small issue. That is, I can't find a way to have the pump sit level on the bottom of my reservoir. I think it will just take some time for the hoses and cables to stretch out. Overall, good buy for me though.
Dosn't fit rimmed tanks very well By Adam on 2/19/2015
Adam would recommend this product to a friend
If you have a top rimmed tank this will still work but it will sit low in the tank, making the waterline below the rim. Contacting Tunze now to see what they are going to do about it if anything. Love their products but the mount for the float switch needs to go back to the drawing board. So as of now I either have to deal with the low water line or fabricate a custom mount. If the float switch fit better I would have given it a 5 star.
Nice auto top off By Todd on 2/8/2015
Todd would recommend this product to a friend
Easy to set up and works great. My only complaint is that it needs a suction cup or something so that is attaches to the bucket as it just lays on its side without this
Good for a few months By Casey on 12/20/2014
Casey wouldn't recommend this product to a friend
My second Ato has stopped working. When the unit works, it's great.
When the first one stopped working, I reached out to BRS and Tunze. I learned that I was basically S.O.L without sending the unit back to them. I just decided to spend the money and buy a replacement.
That was a workable plan for a few months until the second unit died on me. I've decided not to buy another. I'd rather pour the RO water in myself than purchase yet another unreliable model from BRS. I hope they find a more reliable nano ATO to promote.
Works well fills need By Thomas on 12/9/2014
Thomas would recommend this product to a friend
Bought this to top off my nano tank. Set up was easy and does a good job maintaining water level. Lot less hastle than topping of tank daily and keeps salinity more stable
Can't imagine how I lived without this thing By Sean on 12/4/2014
Sean would recommend this product to a friend
No more lugging around jugs every other day, now it's only once every couple weeks! :) This is a huge upgrade and peace of mind. I have a small tank so this is huge in helping me keep my water parameters stabilized. This is a must-have for smaller reef tanks for people serious about their corals.
Works great By Meaton on 11/19/2014
Meaton would recommend this product to a friend
Perfect for my nano cube 28G reef tank
Compact. Works well. By Joseph on 10/29/2014
Joseph would recommend this product to a friend
The unit is very compact, works well, and maintains your water level with frequent small top offs.
My only complaint is the pump doesn't have a suction or bracket so that it sticks to the bottom/side of your reservoir bucket.
Replaced Hydro-fill By peter on 10/7/2014
peter would recommend this product to a friend
I owned the IM Hydro-fill for about 6 months when the controller went out. I've only had the Tunze running for a couple of weeks but I like it better already. Triggers from slight water level drops and I like the idea of the built-in fail safe.
Only complaint is the pump is pretty loud.
14days Dead By Richard on 9/12/2014
Richard wouldn't recommend this product to a friend
problem for the controller pump not working
Great System By John on 8/13/2014
John would recommend this product to a friend
Works great with my 38 gallon
14 months dead By Jason on 7/2/2014
Jason wouldn't recommend this product to a friend
Dead after 14 months. pump is fine brain unit doesnt work anymore.
Great product very reasonably priced By Randy on 5/30/2014
Randy would recommend this product to a friend
Love this little ATO system, and it's affordable for a Tunze product! I've had it for a week and it has been absolutely reliable with no fluctuation in my water level. My sump is a 10g aquarium with a heater, skimmer, and return pump all packed in, so it is a tight fit but it works. I left the cardboard separator between the two magnets because I had read that the magnets being too close can interfere with the float valve. It works like a charm and I couldn't be happier! Best $100 I have spent on my aquarium so far!
To the Top! By Taia on 5/21/2014
Taia would recommend this product to a friend
Tunze has a great product here! It has been working flawlessly to keep my tank topped up and my levels much more stable. It's really one of the most essential pieces of equipment you can buy, it's well made, but my only gripe is the quick connect from the pump to the controller itself. I'd prefer something a bit more salt creep proof! But overall, I'll be buying another one for my next tank as well!
ATO for my nano By charles on 5/12/2014
charles would recommend this product to a friend
installed this ATO on my 28 gal.nano cube.so far it's working great.now my cheap protein skimmer works a lot better because of the constant water level.pump's a little loud so I suspended just above bottom of container and now it's quiet.doing great so far.
Pretty OK By Benjamin on 4/10/2014
Benjamin would recommend this product to a friend
After avoiding a couple of floods when i first hooked it up, i think i finally have it dialed in. If the glass on where you are placing it, make sure to use a spacer, as the magnet affects the float. directions could be clearer about this. after I got it going correctly, i love it.
great By chuck on 3/24/2014
chuck would recommend this product to a friend
Worked great for my nano tank. was out of town 10 days and not one problem
Great Product By reefer63 on 1/29/2014
reefer63 would recommend this product to a friend
Installed in a half hour works great on my biocube 29 keeps water level constant no problem
Works like a charm! By 08TRDOFFROAD on 12/16/2013
08TRDOFFROAD would recommend this product to a friend
Installed this ATO on a Biocube 29. I had a little bit of an issue with the pump not shutting off properly after my initial install. After a short conversation with Tunze customer service we determined the switch was being interfered with by the magnet from my Tunze 9002 skimmer. I moved the switch to the other side of the return chamber away from the skimmer magnet, and it works like a charm!
Good By C on 12/13/2013
C would recommend this product to a friend
I am satisfied with the Tunze product
Best ATO purchase By Oscar on 11/26/2013
Oscar would recommend this product to a friend
I love this ATO easy to put anywhere either in sump or in your tank. I love that it had magnets not suction cups that easily fall of and can dump water into your sump. I also, love that it includes its own pump without the need to purchase one and the replacement its cheap aswell.
Ok product, but be careful By Nano Pete on 11/26/2013
Nano Pete would recommend this product to a friend
After almost flooding my basement twice and contacting Bulk reef supply; I was contacted by Tunze technician and he worked with me to fix my problems. When attaching switch with magnet onto sump glass the maget affects the switch if the glass is too thin. I needed to shim between the two magnets for the switch to work properly. Also, be aware of creating a siphon from reservior to were your supplying ATO water. As far as quality; You get what you pay for...
Pros- works as advertised.
Cons- doesnt come with clear instructions
Excellent ATO By Michael on 11/25/2013
Michael would recommend this product to a friend
I just installed this in a Nuvo 24 and it's working excellent to keep my water level exactly where I want it. The pump can fit right into a 5 gallon polyurethane jug without modification, which is really nice if you don't have a special RO Reservoir. It was easy to assemble and install and the pump is quiet enough to not bother my wife.
My only two complaints of this system: I wish the control box had tabs to mount with screws to the interior of my stand and I would love for the control box to have some kind of LED that either indicates the unit is powered or that the pump is on. I feel like for the price a single LED in the control box isn't a crazy expectation. Other than that it's an excellent product.
Great product By Bobo on 11/23/2013
Bobo would recommend this product to a friend
We'll built . It got to me very speedy with great shipping and packaged well. Works like a charm I will deff be getting another
Great product from Tunze, no surprise there. By Andrew on 11/2/2013
Andrew would recommend this product to a friend
works flawlessly. Only regret is not getting the bigger model with two sensors. the 5 second time out feature is great piece of mind however.
Perfect for my Nano tank By MICKEY on 10/7/2013
MICKEY would recommend this product to a friend
No issues so far. I installed this in an 8-gallon tank so I am especially happy for the auto-cutoff. Seems pretty solid!
upgrade By Red Fish on 10/4/2013
Red Fish wouldn't recommend this product to a friend
I purchased this nano because I was so happy with the 3155. May of this year.
It never really worked like it should, it had an electrical problem right away but I thought I could live with it until just stopped a few days ago. My hubby checked the electrical current and it did not have one.
So I am now purchasing the 3155 to replace this one. If you are trying to decide which one to go with. I HIGHLY recommend the 3155 even though it is more expensive. I wish I had.
Nano ATO jury still out By RikerBear on 9/26/2013
RikerBear would recommend this product to a friend
I bought two of these for my nano reef and for my FOWLR. The one for the nano works great...thenone on the FOWLR sticks and won't always activate (pump not float sensor).
I ordered a replacement pump, so we shall see how it works
Simple and easy set up. By Barbra on 9/7/2013
Barbra would recommend this product to a friend
I purchased this to complete my nano set up. I have a 24 gallon Nuvo by IM and this ATO compliments it well. I installed last night in about 15 minutes. Worked well when I tested it. It fits great in the back chamber.
One of the best additions to my tank! By Paul on 8/8/2013
Paul would recommend this product to a friend
Definitely one of the best additions to my tank so far. It was easy to set up, and I haven't had any issues with it yet. Throw the pump in a container with RO/DI, set the float where you want it, plug it in, and away you go. Water level is staying constant and salinity is stable. It's great! Going to eventually upgrade to the 3155 and use this for my QT/HT.
Does what it needs to do! By Brett on 8/5/2013
Brett would recommend this product to a friend
Installation was simple and easy to understand. Strong little pump. Has no problem pushing the water from the bottom of my stand to the top of the tank (JBJ 28 Gallon Nano Cube w/stand).
Working great. The magnetic mounting system is fantastic. By Arabo on 7/24/2013
Arabo would recommend this product to a friend
I bought this system to pump some distilled water from a 5 gallon water tank to a container that is about 10ft above. The pump was a bit too large to fit into the 5 gallon tank and I had to use a smaller submersible pump but the magnetic mounting system for the float valve alone was worth buying it.
BulkReefSupply offers great customer service and support.
Easy and high quality By Chris on 6/6/2013
Chris would recommend this product to a friend
Although pricey, this system includes everything you need to safely and easily automate top offs, minus a reservoir. The builtin safety features keep your tank from overflowing or constantly running the pump in an empty reservoir.
Very nice little nano ATO By tim on 6/3/2013
tim would recommend this product to a friend
Small...perfect for nanos. Not all the bells a whistles as the full version, but for a nano, you can't beat it. Solid product, very strong magnets.
Great for a 45 gallon tank with 15 gallon sump By Butters17 on 5/24/2013
Butters17 would recommend this product to a friend
Ive been using this product for about 6 months now. Has not failed me yet. This is a must have for saltwater tanks, keeps water levels/salinity the same. my only regret is not getting this sooner..
When i eventually get a larger tank ill get the bigger tunze osmolator for sure.
awesome By ReefDVMs on 5/13/2013
ReefDVMs would recommend this product to a friend
Typical tunze product well built and works like a charm, recommend this to everyone with ATO system
Budget Friendly By Victor D on 4/30/2013
Victor D would recommend this product to a friend
More than enough for my 29g Biocube
Easy to set up (Except the tube for the pump)
Only runs for 1.8 seconds but can be boosted up for bigger tanks. (No fear of flooding)
Float has to be Installed PERFECTLY Vertical. Mine got stuck on the first day. Luckily I was in front of the tank. I knocked the sensor and it stopped pumping.
No alarms. The motor will just pulse every 10 secs. You wont hear it unless the room is silent.
Does what its suppose to. If you're on a budget its a good buy. In hindsight wish I would have held out to buy the reg Osmolator with the alarms and laser eye!
Great Product By Justin on 3/24/2013
Justin would recommend this product to a friend
This is a great solution, especially for a nano reef. The magnet mounts are strong, and I am confident they will hold in place. The unit itself is tiny, and pretty inconspicuous, even if going into a display tank rather than a sump. The only drawback I see is it is a bit noisy when compared to my other tank, which I use an aqualifter on for the ATO.. but it is not obnoxiously loud.
1 bit of info that might be useful to include in the product description is the diameter of the pump. This could be important depending on the top off container that is used. For my purposes, I used a small potable water container designed for a boat or RV. The biggest opening was 1.75 inches, which I thought would be ok for the pump. Turns out the pump diameter is 1/8" larger, so I had to cut a new hole in the tank using a hole saw. No big deal, but would have been nice to know the size before ordering.
Perfect for smaller tanks By Ronald on 3/24/2013
Ronald would recommend this product to a friend
Bought this top off for our 29g tank. Set up took about 5 minutes. Very easy. I really like the back up timer of not letting the pump run for more than 2 minutes. Really assures that im not going to over fill my tank.
does and donts By daniel on 3/10/2013
daniel would recommend this product to a friend
ok i got this ato for to do 2 things add kalk and add top off water at same time. i put it on my redsea max 250 that i upgraded with a refugium because the filter and skimmer just dont cut it on this tank so i built a custom sump for it. after i put the tunze top off in the sump i set it up where when it tops off water right where it poors over the last chamber witch caused current to let me know it was keeping it at same lvl. if theres a little water current it will kok the float bobber some what and wont let it drop freely so make sure if you get this to make sure it tops off enough to make less water current are add something to keep current away from float bobber. other then that i found no issues so far with this product plus it has a run time that if it runs to long it wont run no more and wont until you unplug it and back in to reset it. plus the little pump that comes with it works awsome cant complain.
great!! By geranie on 2/26/2013
geranie would recommend this product to a friend
working great in my 5.5 aio, no problems at all, much better than my jbj ato.
tunze nano top off By pat on 2/23/2013
pat would recommend this product to a friend
product works great easy hook up run tihs on my 40 breeder with 20 gallon sumop no problem keeping the water level thanks brs
previous reviewer, READ YOUR MANUAL By gary on 2/21/2013
gary would recommend this product to a friend
The Nano time-out can be overridden. READ YOUR DOCUMENTATION, as the step-by-step procedure is listed in plain text on pages 27-29 of the manual.
As for securing your waterline properly, a bracket has been included for rimmed and rimless tanks. Again, read your documentation. If the included bracket is not sufficient, then you should think about using an airline mag holder or suction cup. But do ensure you do NOT submerge the tubing below the waterline.
Onto my review:
I own 4 of these units for a variety of tank types, from a picotope 3 gallon to my 46 BF. I have had only one small problem with a snail hitting the float and starting the pump prematurely. Fortunately, the float activates at a level the snail could not reach once filled with water. Aside from needing a little bit better of a pest filter, I love these things. I have the JBJ ATO as well, and it doesn't perform as well. I love the fact that I can buy a switched outlet for the tunze so that I can use my own pump. I have yet to do this, as the included pump is more than sufficient.
I've found this system not only to be one of the best ATO's on the market, but also the most affordable for the benefits! This thing is VERY small as well, the postage stamp sized controller is awesome! I really cant say enough about the quality of this product.
Ive found for the best performance, submerge the entire float assembly below the water line, and gradually raise it till the float switch activates, then raise the mount about 1/16". This will make the float very sensitive to level fluctuations. (FYI my float activates when it reaches just below the halfway mark of the plastic mount)
For those of you installing this in an AIO, you'll find it a much quieter installation if you have the water fill line aimed against one of your inner chambers, or onto the media rack. (No waterfill noise)
In sump/AIO only By nanofreak on 2/20/2013
nanofreak would recommend this product to a friend
I was a little disapointed to find it only uses one float and a snail guard. I'm using in a AIO tank which gives plenty of room to adjust the float/snail guard inside the chamber. It also has no electronic eye or backup float, as well as no warning lights or audible alarms. Does the job, although not as nice as my regular tunze osmolater.
Great little ATO By BioCuber on 2/20/2013
BioCuber would recommend this product to a friend
I have always used the JBJ ATO's for my previous reef set ups, i wanted to try something different, and Tunze has always been one of my favorite and more solid brands in the industry. This ATO tops of more constantly to compensate for any evaporation with a nice safety feature of shutting the pump off after 3-5 minutes if for some reason float got stuck or your evaporation was excessive.
this type os ATO is for sump only, as the previous reviewer stated, so if you don't have a rear filtration from an all in one tank or a sump for your tank, it may be very difficult to set up as you do need an area where evaporation is visible for the float to be in and activate once water is low enough.
Overall, this is a great unit, i am pleased with it as well as BRK's fast shipping and deals.
Perfect ATO for my BioCube! By peequin on 2/17/2013
peequin would recommend this product to a friend
Just installed this last week on my 29G BioCube. This unit is simple, yet very effective. The quality of this ATO is above average. I was deciding between this ATO and the JBJ ATO. I like the fact that this is a complete package with the return pump.
It works flawlessly! I don't really have to worry about snails/critters touching the float valve because it is contained securely in Chamber 3. I also have a fish saver that prevents any animals from getting into the back. I would be concerned if the float valve was in the main display tank, since there is no "backup" float valve.
The magnets are really strong, and easy to adjust your water level. I don't have any concern about the magnets gettting mistakenly moved, they are very strong.
I also like the fact that the ATO has a automatic failsafe built in... turning off after a minute and a half....that turns out to be about 3/4 of a gallon of water. Highly unlikely that you will dump your entire resovoir of water into your tank.
I can hear the pump kick on every now and then. Probably not as accurate as the optical valve...but it works great. It keeps my water level consistent. I am getting better skimmate from my skimmer. I don't have to monitor the tank as much now either. My salinity levels are now more consistent.
I have an SPS dominant systems with large Acro Colonies. My tank has been up for the past 8 years. Everything is thriving. The Osmolator Nano is a really nice unit, not too expensive or overkill. It works perfectly, as advertised.
Not good for anything above a 10g.. By Ian on 2/2/2013
Ian wouldn't recommend this product to a friend
I bought this for my 20g long tank, and it says it can handle up to around 50.. For one, they should really say that this is for SUMP only.. If you plan on adding this to your display (like a lot of us nano-reefers) then make sure your tank is rimless. If you have a rim, you wil never get this adjusted correctly.
The biggest complaint besides that would be it doesn't run long enough to top the tank off. When you have a 20g, it should top it off, but it will run for a bit, and then do it's auto shut off and the tank isn't topped and the sensor is still open. I'm very upset with this purchase, and will most likely be re-selling.