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.