DISCONTINUED - Tunze Osmolator 3155.000 Auto Top-off System

Best ato out there. I have six of these. Never had issues with these ato’s. Other ato’s have failed and overflowed, but not Tunze 3155. I will put/keep my trust in this Tunze ato.

I was on the fence being there are cheaper options, that basically do the same job. However, the setup was very easy and comes with everything you need, minus a reservoir. The fact that it also comes with a failsafe, is very nice. The water level is crucial in my sump. This keeps the water level absolutely perfect and obviously the salinity as well.

I’ve used the Tunze Nano ATO for years without any problems so I decided to upgrade to the Tunze 3155. So far after a month’s usage, it’s meeting my expectations just like the Nano. I would highly recommend this ATO with its fail-safe check valves.

What a piece of mind knowing this equipment is keeping my water at a perfect level every time I check it. We’ll worth the $. Would recommend to anyone.

Being fairly new to reefing (less than a year), I did have some trouble getting things just right. But after a lot of finagling, I finally got it working correctly and have to say that I really like this ATO! I had no idea how much easier it would make things. No more manual top-off!

I love this ATO!! Totally worth the money. I had to do a little bit of adjusting initially, but it is working like a champ!

Tunze ATO is the only way you want to go in this department.<br><br>Tunze ATO is consistent and reliable and made to last. <br><br>Always have faith in Tunze products from past usage.<br><br>Very easy setup and worked flawlessly from the jump.

This ATO worked great right out of the box with no issues. It was easy to set up. It's been installed for 5 days now and water level is always spot on.

Great product overall like others have commented the optical sensor is sensitive so clean it out of the box. Works perfectly since then. Only real complaint is price but everything in saltwater fish is expensive. Lol

After my J* auto topoff failed, i decided to give this a try.<br>Purchased the extra plug to use my own pump that fills my kalk reactor. Operation is smooth thus far, the auto topoff eye is very precise when the level drops, ez setup. Xtra Plug i purchased however, needed wires to be snipped, to fit the main units clamps, was the only pain to figure out, since there are no instructions for the extra plug.

The 9001 skimmer from Tunze was very easy to install-just follow the comprehensive instructions and make minor adjustments as necessary. Started producing skimate right away with absolutely no issues. I’d highly recommend it for anyone with a BioCube or where space is an issue.

Was a little hesitant to purchase this item, its on the higher end $ wise for a top off. But this unit brings everything you need! and has three fail safe features which for me was the key since my top off tank is 60Gal. I read multiple reviews both here and on forums and this was the highest recommended ATO. <br>The only feature I wish that this unit doesn't have is suction cups to hold the pump in place. I solved the issue by zip tying it to a pice of egg crate which kept it in the correct position. Not a big deal as many people use this with Kalk and it wouldn't be ideal to keep it on the bottom.

I chose this auto top-off system since it has been uniformly praised around the web as the best. It works great. The instructions are less than clear and it was more of a challenge to assemble than I was anticipating. After troubleshooting with google (I had to turn the pump upside down to empty the air out of it while under water before the pump would efficiently pump water) it works like a charm.

The redundancy of this unit is awesome. I feel safer knowing that there's a float as a backup in case the sensor (eye) should ever fail. Just be sure that you don't place the pump lower then the water level as if you are lazy like I am and don't keep your ATO container filled at all times, the water will backflow after the unit turns itself off in order to save the motor. Still, I thought it was actually an awesome feature of the unit for it to save itself. It was easy to assemble and place in my refugium, taking up little space under my cabinet. Basic functions and very easy to use. Great product!

I use to manually top off. Once I started using this, I realized it was something that I wish I would have done years before. The system comes complete with everything you need and is easy to set up. That being said, mine came with 2 sets of magnets which confused me in to thinking I needed to use them both. System actually works better if both sensors are hooked up to same magnet. System is great and I have never heard of one failing. Would definitely purchase another and recommend to everyone.

Overall works well, big time saver, and adds water as needed avoiding dumping a large amount of fresh water in the sump at once. Only issues are it somtimes get confused when powered on and overfills until the float switch stops it. Only other issue is the pump is really noise. Added a tunze power adapter, so I could use a much less noise pump. Overall still a great product.

Worth every penny.....Imagine the headaches for early marine hobbyist before Tunze invented this revolutionary product ..Tunze invented it decades ago and now everyone copied it..( cheaply I might add from direct experience) Why did I wait so long to buy a Tunze and save all that money and aggravation on cheap knock offs ?<br> Buy the original and give credit to the people who came up with the brilliant idea.. You will not regret it like all their top quality products..How did anyone manage to keep their salinity and evaporation under control before ?

All I can say is SWEEEEET!

Extremely easy to setup and never have to worry about topping of your water again...

I really enjoy having this on my main Display tank. I never have to worry about it working or not, the level stays put with this thing installed. I highly recommend this item. It has what you need, an adjustable pump, backup/failsafe mechanism, and all in one package.

So far so good. Not sure how I went so long without. Tank evaporates about 3 gallons a day.

this is by far the best ATO I have ever used. setup was easy &amp; adds water precisely to the level I wanted. gets a 5 star from me~

This is by far the best make-up water pump system available. This is my second one because after 2 years of service I dropped the first one in my sump. Very dependable and very precise. I dd not hesitate to buy another after I drowned my first one. Pump can run dry without damage and very simple to operate.

This thing is awesome! It was a little finicky at first, but once I did some forum searching I got it going good and it has been spot on ever since..<br><br> P.s. wash the optical sensor with warm soapy water before installing it will save you some stress with the start up.

This systems work perfectly. I would highly recommend this unit for anyone needing a ATO. Comes with every thing you need except the bucket to put the pump in. <br><br>Cons:<br>Anytime you unplug and plug the control unit in, the pump runs for about 10 seconds.

It works well however the Tunze mounting brackets are poorly designed once you figure them out it is a simple install.