- Osmolator Universal 3155 Auto Top Off - Tunze
Why does BRS recommend this?
Bulk Reef Supply tried many different water level switches and auto top off solutions before giving the Tunze 3155 Osmolater Universal Auto Top Off BRS Recommended status. Despite its higher price this is by far our favorite solution. Spending the extra money on a Tunze Osmolater will give you that extra peace of mind and insurance from having a disaster that ruins carpets or hard wood floors. For the value, and reliability it is hard to beat.
Max Head Height: 7.2 ft
The Tunze Osmolator 3155 is one of the safest ATO’s available. It utilizes an electronic eye sensor to monitor water levels and a backup float switch sensor with an optional audible alarm. The controller protects the quiet metering pump from running dry and reports an empty storage tank. Two magnetic holders for sensors and multiple mounting brackets included as well as a pump.
LED indicator lights the Osmolator will allow you to visually see if their are any issues with your top off system.
Two technologies of water level monitoring, and built in safety back-ups.
The optical eye sensor will keep the water level very steady to keep the salinity from fluctuating in your aquarium. The Osmolator does work well with kalkwasser.
Max Head Height: 7.2 ft
Note: With any pump, kalkwasser can cause premature wear. New pumps are available at a very reasonable price.
Reliable product and great service By Shayne on 1/8/2020Shayne would recommend this product to a friendJust had to send my unit to Tunze as the optical sensor had failed which has to be replaced and calibrated by their support department. They said it would be $30 to replace. I was past the two year warranty so I wasnt concerned about the service cost. Received the unit back fixed with no invoice. Emailed them and they said no charge for the repair even though it was 9 months past warranty.
Awesome ATO! By Luke on 12/28/2019Luke would recommend this product to a friendI've been using one about a year. It's gone dry and caused no damage. Still running strong. Awesome!
This is a Greate ATO By Mark on 11/22/2019Mark would recommend this product to a friendI would definitely recommend this ATO to anyone who is currently shopping for one. I've had it running for over a year without an issue. Setup was easy. Highly recommended.
buy it By jeremy on 11/19/2019jeremy would recommend this product to a friendDon’t be scared off by price, it’s absolutely worth the price tag. super easy to install and set up
Best ATO at this time By Michael on 11/5/2019Michael would recommend this product to a friendI have tried a few and this one is the best all around. One issue - The lights on this are impossible to view at an angle (minus a star) which could be easily and cheaply fixed by Tunze. The Duetto is pretty cool except the sensor just isn't stable enough and can rotate on you. My only disappointment is I bought it here 5 days ago for $20 off and now it is an even better deal at $40 off. You can't beat it for $159.
Great and reliable topoff By James on 11/1/2019James would recommend this product to a friendI have used these for years, and they are as reliable as can be. The only issue I have ever encountered is slight overfilling, which the float switch catches and alarm goes off. These are 100% my fault for not doing routing maintenance on the optical sensor. The most you'd have to do is a quick cleaning with a soft toothbrush maybe once a month or two.
The pump is not silent, but also not too irritating. It would be nice if they made a quieter pump but its low on the list of my worries.
To those reviews saying that it pumps water automatically when plugged in/powered on, yes it does that is it running a cycle to be sure all is working. If the that pumps in too much water for your liking, consider clamping the tube to reduce flow a bit. I run mine form the cellar with about 6 feet up, and its a fairly low flow.
Again, great top off form a reliable company.
Controller failed no customer service response By Mark on 10/31/2019Mark wouldn't recommend this product to a friendI have had this for a year and a half. Worked great for 8 months then the controller failed made several attempts to reach customer service as well as the rep for tunze with no response. I have purchased several times thru BRS and had no issues . This time was very surprised that no response by email or messenger and no response at all from the rep. I am having to.manually add water daily by tripping the controller to turn on by unplugging and plugging back in . I have cleaned the eye and has not helped. Maybe just a bad controller . However it was easily remedied back a fee months . I've waited to post a review but now I figure why not have nothing else to lose.
Great product! By Adam on 10/25/2019Adam would recommend this product to a friendEasily set up and functions flawlessly. One of the best investments for my tank.
The standard to which all ATOs are compared By Matthew on 10/12/2019Matthew would recommend this product to a friendThe full-sized osmolator has been the most trusted name in ATOs for a long time. I've used a couple of float switch based ATOs before and they will eventually fail and generally fail "on." With the Osmolator I have been able to adjust the output of the included pump so that even if it fails on the water trickle into the tank won't overflow the back part of my IM20 fusion. I get a nice reminder that the overflow sensor works when I put my hands into the tank as the displacement of water from my hand in the IM20 will trip the overflow alarm. I'll gladly take the grating beep when working in the tank to be sure the ATO failsafes are still working properly. Having used the non-adjustable nano osmolator on a larger tank (red sea 250) this piece of equipment will follow me to the next upgrade.
"It just works" By Matt D on 7/23/2019Matt D would recommend this product to a friendI think the rest of the reviews and the reputation of this product speak for themselves. This is probably the single most important upgrade you can add to your tank. Maintain your salinity for less than $200 with this reliable little device. The ONLY thing I would change is that the water level monitoring device can be a bit hard to move if you wanted to move it by just sliding the external magnet: you really need two hands.
Pretty good ato By John on 6/16/2019John would recommend this product to a friendI have this pump for over 3 years and I've had the pump over fill and start beeping here and there but it hasn't done any real damage. I'm more writing a review on the pump, I run it dry probably at least 3 times a month for sometimes over a day and it still works. Pretty impressed with the pump especially
Pump failed in under 3 months of use By Steve on 6/12/2019Steve wouldn't recommend this product to a friendPump failed after 3 months of great performance. Just ordered a new pump and will give it another shot. If it fails again will move on to a different device. Pump never ran anything other than fresh RO water. Absolutely no reason for pump to fail so soon
I have a litermeter 3 that has failed. It pushes water about 30 feet from the litermeter to a sump tank. Will this pump do the same?
The max head pressure on the included pump is about 7ft. It likely wouldn't be well suited to this application. That said though, you can get the additional switch socket adapter which would allow you to control any pump via the osmolator system. That way you can use a pump that can handle the head pressure.
If i have a wave maker and this ATO in the same tank (I don't have a sump), would the waves cause the pump to turn on and off constantly? Thanks
In theory it could present a problem but the circuitry in the Osmolator should help to prevent that. Every time the ATO is triggered it runs for a minimum of 15 seconds. It adds overfill to prevent short cycling. In most cases this should be sufficient unless the height of your waves is constantly changing.
How much head will the pump push
The pump on the osmolator has a max head height of 7ft.
Hi, by head pressure does this mean how many feet the pump will push the water? So if my pump is in my cabinet under my tank will it push the water to the top of my tank? Thank all over at brs..
Head pressure is the maximum height that the pump can push water vertically. If your tank is higher than the Head height listed this will not be able to work. Feel free to let us know if you have any further questions!
You say additional switch socket adapter to handle more head pressure. Where can i find this? I traveling about 15 feet 9 of that is up.
Will the sensor fit in the sump of an innovative marine 30L ?
This will work great in the back of a nuvo 30! Feel free to let us know if you have any further questions!
What are the dimensions of the pump at its widest points? I have an ATO reservoir with a small opening, and I'd like to know if this pump will fit through the cap.
What is the measurement on the pump, as in the widest part? I need to know if it will fit in my container I plan to buy.
The diameter of the pump is just under 2" this is how wide the cap will need to be in order to allow the pump to pass through.
Is the retaining magnet waterproof?
What are the dimensions of the blue Tunze controller module/box. I am trying to determine if this will fit on an existing mounting board. Also, how does it mount? Adhesive or punchouts in the back plate. I don't see screw holes like the Apex modules have. Thank you.
This will be 4" long, 2.5" wide and 1" thick. it will require a Velcro pad to stick or to be used with double sided tape.
I have a 10 gallon tank and am concerned with salinity swings. I top off my tank every day but I'm afraid most of these ATO would not fill the evaporated water before my salinity starts to rise. What is distance vertically from the low to full position?
The optical eye sensor will usually sense and fill within the range of 1/4" Feel free to let us know if you have any further questions!
I have turned the control up to the max however it will not keep up with the evaporation? my tank is a 120 gal with 35 gal sump.
If you have calibrated the pump to maximum output and it is still unable to keep up you will want to ensure the pump is filling the proper amount. It may be that the head height (the vertical height the pump has to push the water) could be too high or other pump related problems. We have used the osmolator on larger systems with quite heavy evaporation with great luck. If the issues continue you will want to contact Tunze directly to see if the pump is working correctly! I have included their contact information below!
Tunze – 512-833-7546 firstname.lastname@example.org
Will this work with the Apex controller?
The Tunze Osmolator is an entirely self sufficient system. It is perfectly fine to connect the Osmolator to one of the Apex's power outlets incase you wanted to cut the power for some reason (like when you are doing a water change) though the Apex isn't capable of reading the Osmolator's sensors or anything of that sort.
Hello. I bought a used Tunze osmolator today. Do you sell replacement parts, such as the magnetic sensor holder. And, what is the best way to clean the sensors? Thank you. :)
Could you please post or email me, what differs from the 3152 and the 3155?
The 3155 will have 2 sensors the mechanical float and the optical eye. The 3152 will only come with the mechanical float switch. Feel free to let us know if you have any further questions!
Can you tell me the diameter of the wet side unit? I need to make sure it will fit inside the return pump side of my bio cube 14. I’m worried the sensor will not fit due to the narrow area I have to work with.
I have the -osmolator nano 3152 ATO and I was wondering the water level controller can be adapted to it
Would you happen to know the max head pressure of the Tunze Osmolator's pump?
The max head pressure on the osmolator pump is 7ft.
Can this connect to the Apex controller?
I purchased the osmolator from your site and was under the impression it had an alarm that went off if the ATO container was empty to prevent the pump from burning up. I've tested this, but my pump just keeps running and there is no alarm?
This osmolator will run for typically 10-15 minutes in a dry container. eventually the controller will sense that it has not filled in a timely manner and should turn the system off. if this continues to not be filled there may be red flashing on the controller. For direct assistance you will want to contact Tunze directly!
What is the power consumption of this unit?
The power supply has 12V, 1600mA maximum output, connected to a watt meter with the pump running, the draw at the outlet is generally around 8W at 115V with the pump running. The entire system uses 1-1.5A at 12V depending on pump speed setting and head pressure.
What pump do you suggest to go with the3155 osmolator?
The Osmolator actually comes with the pump right in the package so you don't need to buy one!
How far can the pump be from the controller? Or, how long is the wire from the pump to the controller? I need to have the reservoir in a different room from the tank. The rise is only 2' but I need to go through a wall and about 10' from reservoir to sump.
The pump has 1.2 meters of cable (~3.9'), the controller has 1 meter of cable (~3.2') that connects to the pump, overall you have roughly 7ft total. You can extend it with speaker wire if you have to, but you only have 9ft of hose with it. If you have any other questions let us know.
Happy reefing! c:
Can i purchase this item with a australia (SAA3) wall pug not a north america one thats shown in the photo?
We appreciate your interest, but I'm afraid our distribution area is limited to North America and all of our equipment is wired for standard US 110v electrical.
Have a great day!
Just wondering if I need 2 ATO. I know you can place it either in the sump or in the tank, but my question is if I place it in the sump will it also refill my tank in that process. I don't see that happening but if it does please let me know.
If you have a sump, it MUST go in the sump, in the chamber where your return pump is. This is the only area of your tank that will have a changing water level depending on evaporation (unless its far too late!). Only one ATO would be necessary but it must go in that location if you have a sump.
My Tunze Osmolator ATO keeps getting stuck in the ON position. I soaked the electronic eye in vinegar and it was fine for a week, but then it stuck on again. Do these electronic eyes fail after many years of use? I've been using it for about 4 years. Is there any way to replace the eye without having to buy a whole new system?
We run into very few issues with these but after that length of time I would imagine its possible for any component to fail. We don't have individual parts like the optical eye, but if you give Roger and company a shout over at Tunze USA, he might. At the very least he could likely help you narrow down exactly what it is. The number I have for them is 512-833-7546 email@example.com
Does the pump get placed directly in the top off water reservoir? If so what are the dimensions of that pump? I am trying to decide what kind of reservoir I can use before purchasing a ATO.
That is correct. Its a submersible pump that gets stuck right into the top off water. If your interested in this ATO system you should give this blog article a quick read. It goes into a lot more detail on the system (which is one of my favorites).