I'd give it 6 starts if I could By Dariush on 3/19/2014
Dariush would recommend this product to a friend
All I can say is WOW. This thing is great. Setup was about as easy as it gets (Reader's Digest version below):
1. Mount sensors on bracket
2. Mount bracket to tank
3. Mount controller to stand
4. Connect tubing to pump and tank/sump
5. Connect pump to controller.
On my 20 gallon nano reef, this thing keeps the water level dead on accurate, and the default pump setting works just fine, although it is adjustable via a variable pot inside the controller.
The pump makes a slight hum while it is running, but it is hardly noticeable, and since it isn't running all the time, odds are you will never hear it.
flawless By angelo on 3/17/2014
angelo would recommend this product to a friend
works perfectly since i got it over a year ago. never an issue
Great Product By TEM on 3/17/2014
TEM would recommend this product to a friend
Best auto top off I know of. This is the second one I've purchased-for a second tank. Reliable and dependable.
Very reliable product By Nil on 3/14/2014
Nil would recommend this product to a friend
This is the most reliable aquarium products that I have ever owned. Works really well. I installed it in my sump. Maintains the level just as it promises to do. No mechanical parts in the sensor, which is great. The pump ran dry on couple of occasions due to my mistakes, I thought I killed it but it still runs. Great product.
Like a Charm By Bradley on 3/12/2014
Bradley would recommend this product to a friend
I have the smaller ato for my biocube and it works great, so I had no issues with trying this ATO for my new 90. Just set up the tank about 6 weeks ago and this thing works like a charm. Constant water levels is a foundation for keeping other levels in check.
Awesome!!! By Nick on 3/9/2014
Nick would recommend this product to a friend
I bought this ato when it was on sale for black friday and let me tell you dont waste your money on anything else. This is well worth the money and I would buy it again ovre and over. Tunze knows how to make equipment. Happy Reefing!!!
Nice ato By Ryan on 3/6/2014
Ryan would recommend this product to a friend
I've had this top off running on my tank for about 6 months now, i can say it works great but has a couple of flaws. The electronic eye can slime over somewhat easily if you don't watch it. Secondly, if the water level in your top off reservoir is higher than the outlet of the pump tube it will create a syphon and drain the whole reservoir into your sump. I've had it almost overflow twice, now i use a 5 gallon bucket on the floor which lasts about a day :( . Overall a great product, a little $$ though.
Best ato By Bryce on 2/24/2014
Bryce would recommend this product to a friend
This ato is the best one i've ever owned. Never failed!worth the extra cost!
Great Product By Jesse on 2/21/2014
Jesse would recommend this product to a friend
Easy to set up and works great
Best ATO ever By Jonathan on 2/4/2014
Jonathan would recommend this product to a friend
I was a bit put off by the price of the Tunze Osmolator ATO, but when it went on sale at Thanksgiving I went ahead and took the plunge, and I have rarely been so pleased by a piece of equipment! The instruction manual if very helpful, without much useful info lost in translation. Setup was easy, and after on minor overfill due to me not having the two sensors far enough apart, my sump level stays within about a half inch of the same point at all times. I strongly recommend that anyone considering an ATO buy this system. You get what you pay for, and in this case its the best ATO on the market.
Plays well with fish, but requires supervision By cp on 1/28/2014
cp would recommend this product to a friend
Overall this ATO works really well. It's nicely made and it was fairly easy to set up.
Four stars because the sensor got filmed over and stopped working within a week. It was easy to clean by wiping it off and then it worked fine again. The film was my fault, since I hadn't gotten the dosing dialed in the new tank, and I caused precipation by adding Ca and alk solutions to the sump. But even so, it means that the unit is not maintenance free so I will have to get my tank sitters to check the water level and will have to explain how to clean the sensor if needed. Kind of a bummer, since ease of fish-sitting was one main reason for buying this unit.
nothing but problems By Greg on 1/17/2014
Greg wouldn't recommend this product to a friend
I switched from a JBL after the hrs video, and although the pump on the unit is quiet, and moves a lot of volume, I have had nothing but problems maintaining my aquarium salinity. The Tunze will constantly over fill the tank, and the alarm will go off. If I wasn't hooked up to an apex controller, It would of destroyed the tank. I've tried all the jumper settings, and nothing seems to make a difference.
I've been fighting this for 6 weeks now, I'll be switching back this weekend.
Pump is the weak link By Marc on 1/17/2014
Marc wouldn't recommend this product to a friend
It's a shame, but the pump they use for this system is cheap trash. I'm on my third replacement is only seven months.
Never Fails By Scott on 1/9/2014
Scott would recommend this product to a friend
After seeing a video of Ryan talking about it, I purchased one and would not use anything else at this point. My water level changes very little before this thing kicks on giving ultra stability in my SG. Had mine for a year and have had absolutely no issues with it. The pump is always submerged in kalk and hasnt failed yet. I have a spare on hand just in case though.
There is a breakin Period By Jared on 1/6/2014
Jared would recommend this product to a friend
At first I thought I had a issue. I have come to find out that all Tunze ATO units with the optical sensor need a "break in" so the bubbles won't interfere with the level reading. I soaked the optical sensor in vinegar for 5 hours, cleaned off, and mounted. I havent had a level sensing issue since. I am currently using this with Kalk to top off my 65 Gallon system.
love it By trent on 12/28/2013
trent would recommend this product to a friend
no more carrying buckets through the house. easy to install. keeps my refugium at the same level day and night. keeps salinity steady.
the electronic eye is the best part. nothing to get stuck. great product.
Do not hesitate... just get this! By Easiest install ever on 12/18/2013
Easiest install ever would recommend this product to a friend
I used to have to fill about 2-3 gallons per day into my 120 gallon system, now I just keep my reservoir filled up, topping it off about once every week or two. This is well worth the price. No idea what the other reviewer was saying about a break-in period. Worked instantly, and has been working fine ever since.
Has a break in period By Michael on 12/16/2013
Michael would recommend this product to a friend
Easy installation. However, it overfilled and the alarm went off. I have read it has a break-in period so I hope this to be the case. I even washed the sensor before install.
Great Product By Dustin on 12/12/2013
Dustin would recommend this product to a friend
This top off was very easy to install and has been working flawlessly.
Marine Hobbyist Must Own!!! By BuckeyeFrags26 on 12/11/2013
BuckeyeFrags26 would recommend this product to a friend
I currently have one on each one of my tanks. One heck of a product, nothing else to be said about it. The company name says all you need to know when it comes to quality equipment. By far the best NO Instructions needed system. But if it's your first one you own, atleast read the instructions, it does have informative information you do need to know.
Better than my old JBJ ATO By ToledoNate on 12/10/2013
ToledoNate would recommend this product to a friend
I used the JBJ ATO for the first year of my tank. I have a 2.5 gallon jug for my ATO and I would find the whole jug emptied and the water level in my sump far higher than my float line. My protein skimmer needs to be in a constant depth of water and would over flow when the ATO failed in the off position.
My new Tunze Osmolator is great. It keeps a perfect level in my sump and my protein skimmer has never worked better. I especially like the Tunze because it pumps a fairly consistent amount of water every time it turns on, allowing me to more accurately dose Kalk in with the ATO.
Oops forgot to read instructions! By BigMo on 12/7/2013
BigMo would recommend this product to a friend
Never needed instructions! Works with in 30 seconds after plugging in. 1 minor level adjustment and topped off right to the full line. Checked the alarm by sliding float up and loud and clear. One of the coolest toys for my 55 gal I've invested in. No more gallon jugs filling up the sump for me!!!!
Works By Martin on 12/6/2013
Martin would recommend this product to a friend
This auto top off works for me. the only think I found odd is that when I replug it in after a water change, it starts up for about 30 seconds even though the sensor is submerged. I just hold a cup under the outlet for that 30 seconds to collect the extra water. After the initial plug in it works fine.
Solid Product By Jim on 11/19/2013
Jim would recommend this product to a friend
This is my 1st ATO system I purchased. It really makes life so much easier. No more filling sump everyday and my salinity stays constant. I hooked it up with a 10 gallon ATO tank from Advanced Acrylics and it works great. Very well built. The only complaint is the pump is a little loud but not a huge deal.
Great Product By Troy on 10/30/2013
Troy would recommend this product to a friend
I have only used a couple of ATO systems and this is far superior to others. It's well worth the extra money. My previous ATO used dual float switches that would calcify or be affected by turbulence in the sump. This is spot on every time. I have a larger system 300 gallons so the pump being able to run for an extended amount of time is great. I also like that the pump will automatically turn itself off after a certain amount of time as another added precaution
Great Quality! By Jorge on 9/8/2013
Jorge would recommend this product to a friend
I have to say that this system has made my life much better! I don't have to worry about adding fresh RO/DI water every other day due to evaporation, it keeps my water at the perfect level and creates a much more stable environment for my fish.
The system was incredibly easy to install and it works perfectly. This will be the only top off system I will use on future tanks.
If you need a top off system... buy this unit and don't compromise on anything else!
Great Reliable Product By Ryan on 8/25/2013
Ryan would recommend this product to a friend
Best ATO in my opinion, very accurate and simple to set up. The initial set up was easy but had a little trouble with bubbles covering the optical sensor causing it to overflow and make the float valve go off. I turned it off and let it sit in the water for a few hours, then plugged it in and has worked ever since.
A little spend, but a crucial part of the aquarium
A good product that could use a little refining. By Matt on 8/15/2013
Matt would recommend this product to a friend
Overall I found this product easy to set up and install. Once properly set up, this has kept the water levels in my sump very stable.
I do have a couple of small complaints though:
1) I wish the instructions had come right out and said to place the primary sensor in an area of the sump with NO, and I mean NO, air bubbles rather than telling you that in the trouble shooting section.
2) A better mounting system for the controller. A couple of stick on pieces of Velcro? A simple mounting bracket or even molded screw holes would be better.
3) The LED indicators are unshielded and impossible to read unless you are looking at the controller straight on.
Honestly, where is the much hyped "German quality and attention to detail?" For $200+, I would think Tunze could do better.
Best ATO money can buy By Joe on 8/12/2013
Joe would recommend this product to a friend
Great product. Exceed expectations. Even though it's a little pricey but it does come with the pump so that make it reasonable. Very acurrate and trustworthy. I expect it to work a long time.
Quality product By Sal on 7/21/2013
Sal would recommend this product to a friend
This was very fun and simple to install. It works flawlessly.
Reliable and effective By Andrew on 7/20/2013
Andrew would recommend this product to a friend
I have had this running a few months on my 80 gallon reef. The unit was relatively easy to set up, the instructions are just poorly laid out. Once set up there were no issues and it has been keeping my water level consistent.
Well worth the price!!!!!!!!!!! By jhmeresqu on 7/8/2013
jhmeresqu would recommend this product to a friend
I utilized it as my ATO for my RO/DI water return to sump system to replace evaporated water. Works great , love the fact that it has the Sensor Eye and the backup float switch. Can't get enough redundancy. A little pricey but well worth it.
Great investment By Mpek on 6/30/2013
Mpek would recommend this product to a friend
All I have to say is that this system makes my life a lot easier! As long as I keep my ATO container full it runs flawlessly. I would recommend this to anyone.
Not bad By Shalashaska on 6/28/2013
Shalashaska would recommend this product to a friend
I've had it so far for 3 days. The set up was easy. I dident have to use the instructions what so ever. The only thing I found so far that is a issue is that micro-bubbles from my protein skimmer like to settle on the optical eye, thus giving a false water low indication. I just moved it to a better location, problem solved.
Great But there is a break in period. By Will on 6/26/2013
Will would recommend this product to a friend
So for the first 3 or 4 days the "eye" sensor has a hydrophobic film which will make the sensor think it is in the air and will continuously pump water until the float switch will shut it off I recommend you leave the sensor in the sump for 2-3 without turning it on that will resolve these issues.
Overall nice ATO By PMK on 6/17/2013
PMK would recommend this product to a friend
I am pleased with this ato unit. I had some issues with the pump just kicking on and staying on. Dropped 2L of rodi into the system and stopped when the float kicked in. I couldn't figure it out and thought I might have a bad unit. So broke it down off my display and set it up on my mixing tank. The same thing happened. So ran through the set up again and disconnected the pump from the power supply wires and connected them up again. That did it. The pump no longer kicks in and stays on. Haven't seen this in other reviews or the Tube but did see a review about a weird first hour break in period. Guess it was the connection or the break in period. But its been on my display for a couple weeks now and has kept the water level very stable. Been monitoring the salinity and everything has been real stable. I think it will be a long term success. I agree with some other reviews that it seems a bit delicate for a couple hundred bucks.
Great Product! By Andy on 6/8/2013
Andy would recommend this product to a friend
I purchased this item about a year ago for my Red Sea Max 250. The skimmer on that tank is very finicky and needs constant adjustments to work properly when the water level changes. This ATO has fixed that issue for good! I have a five gallon bucket of RODI water sitting under the tank for top off purposes and the Osmolator takes care of the rest. My tank water level is always where it needs to be and my skimmer is running at optimum efficiency. If you're looking for a good quality and reliable ATO look no further!
Working great for the past 8 months By Ron on 6/3/2013
Ron would recommend this product to a friend
Have had this ATO unit for almost 8 months on a 90 Gal reef with no issues. Working as good today as the day I got it. Set up was easy. No more having to add top off water every day.
Excellent Product, Well Worth the extra $$$ By Huck on 5/31/2013
Huck would recommend this product to a friend
Initially, I was reluctant to spend the extra money on the Tunze. I did tons of research and I saw this product had excellent reviews, but what sealed the deal for me is, I was reading reviews on a JBJ auto top off system and someone who purchase a JBJ stated that he wish he would have went with the Tunze and not taken the cheaper option.
Unit has been in service now for approx 3 months and not a single problem. Definitely the way to go!
Top-notch !!!!!!!!! By Jimbo on 5/30/2013
Jimbo would recommend this product to a friend
Sweet, could't ask for a better quality ATO system.Like the redundency with the Sensor and the float switch combined.
Excellent product. Worth the extra investment.
Works great when it is working, if you can figure it out By tramboneplayer5 on 5/18/2013
tramboneplayer5 would recommend this product to a friend
The instructions for this are terrible. For something that costs this much, I think they could have hired a better translator to write the instruction manual. After watching people on youtube and reading threads on reefcentral, I am pretty sure I have it all together, but the water line occasionally falls out of the pump and the pump will continue to run while shooting water up in the air. Be sure to have a lid on your water reservoir.
For $200, I don't get a finished product? By Mike on 5/14/2013
Mike would recommend this product to a friend
I haven’t set it up yet and I’m sure it will work as advertised, but it contains a feature that is a pet peeve so excuse me while I rant a bit. The pump connects to the controller via two bare metal wires that have to be manually wired to a “terminal” connected to the controller. The manual does not explain how this is to be done. I got instructions from Tunze and had the strong impression that the rep thought I was either lazy or stupid for asking. I may be both, but when I pay more than $200 for an electrical product, I expect it to be fully wired. What would it have cost Tunze to add two snap in parts to connect the pump and the controller? A few pennies extra for each piece? So why didn’t they do it? I suspect because Tunze, like other major manufacturers of aquarium equipment, assumes that they can cut corners and the customers won’t complain. Well, it’s really no big deal, right? But what if you bought a top of the line coffee maker for $200 and it required that you wire the plug to make it work? Would that be ok? How about the numerous Chinese manufacturers who provide instructions for their product in absolutely incomprehensible English? I could go on. But if this kind of thing occurred in any other consumer market, there be an outroar. But since it’s just an aquarium product, we just shrug and look for a work around. IMO, we deserve better
good for a while By lwillis22 on 5/14/2013
lwillis22 wouldn't recommend this product to a friend
I have had this product running on my 125 gallon tank and it has been a life saver. However, it started malfunctioning and I had to return it to Germany to get fixed or replaced. It cost me $35 to ship it there and that was the cheap route. It has been 1 1/2 months since I shipped it out and still no contact from them.
What a Great Product: By Bruce on 5/9/2013
Bruce would recommend this product to a friend
For anyone that wants peace of Mind about their aquarium, this is the product for you. An accurate, automatic device that will add DI water or Kalkwasser to your Sump is the way I use it. Perfect for the person that makes short trips, without the worry of evaporation causing your salinity levels to rise while your gone. A perfect 5 from Me.
A MUST for larger tanks with large evaporation rates! By RandoReefer on 5/7/2013
RandoReefer would recommend this product to a friend
After upgrading to a 125g tank with a 30g sump, I noticed my evaporation rate upgraded also. One week of manually topping off 1.5gal per DAY, was enough for me to pull the trigger on this ATO.
I really trust the sensor on this system! I was close to buying the JBJ Auto Top Off but I'm so glad I put up the extra money for this one. It is sleek, provides a variety of setup options, VERY Accurate, and easy to setup. I gave it 4.5 stars, because it could have used a few more directions or a FAQ section.
Why didnt i get one sooner! By Jason on 5/1/2013
Jason would recommend this product to a friend
I finally made this purchase and its a life saver!
comes with everything needed (except water container).only issue is the
eye sensor gets micro bubbles on it when first installed which causes it to pump water continiuosly till high level alarm shuts it off.best advice is clean sensor with vinegar and let it sit in your sump for a couple days then its trouble free.
The best hands down. By Alex on 4/13/2013
Alex would recommend this product to a friend
Tunze osmolator top off is the best system you can buy. Well worth the price, comes with its own pump and has 2 different technologies working flawlessly to protect your tank and home from a flood.
great ATO By illya on 4/13/2013
illya would recommend this product to a friend
This is my second unit i'm ordering, first one was about 2 years ago. This is for a second setup, the first one is doing great. The one problem with these is the power plug. After sometime it becomes corroded and you get strange errors like overfill alarm wont stop. But if you have any problem the first thing to do is take off the 2 screws and clean the port and the plug. I cut a nail file down to about 1/8" to clean the port, and just a drill bit to scrape the plug inside. worked great and im good for another 6 months at least. At some point i'll just solder the wires and never deal with it again.