Auto Top Off for Saltwater Aquarium Water ATO System for Both Reef and Fresh Tank - Green

This was easy to set up. It is small and discreet. It has stabilized the water level and appears to work as expected. The sensor does what it was created to do. So far, so good! And the price point is perfect.

Really happy with this ATO system. It keeps the water level steady without any hassle, and it works great for both saltwater and freshwater tanks. Setup was simple, and once it’s running you don’t have to worry about topping off the tank all the time. A great upgrade for any aquarium setup.

I read the reviews saying "the sensor broke and it overflowed my tank" and thought boy that won't happen to me... Well it did. DO NOT BUY THIS PRODUCT. You'll wake up one morning to an overflowed tank with 30ppm freshwater/saltwater combo and needing to take an emergency half-day from work to solve the issue. I bought two for both my saltwater tanks and I'm going to have to return both of them now.

I would like to start of buy saying I have been in the aquarium hobbies for over a decade and had always taken steps to reduce evaporation as much as reasonably possible. However after many years of topping off my tanks manually I decided to look in to an ATO, after reading many reviews and seeing a few videos I settled on this one and I'm glad I did. The ATO is very simple to to set up in just a few minutes. The sensor that goes inside of your aquarium is very small and the magnet used to secure it in place feels adequately strong enough that I'm not worried about it falling inside of my aquarium. I purchased a smallish 7 gallon water container one would use for camping to use as a reservoir for hold additional water and the small pump head fits very nicely inside. So far it has been working great. There is very and I mean very little noise heard from the pump when it kicks into action and the only time I've heard it was when everything in the room is shut off and its stone silent in the room. The only draw back that I can think that may throw some people off is the sensor it's self is a very very bright night light so best not to use in a bedroom I'd say if you like the dark that is but seeing as the aquariums in question are located in my home office / game room it doesn't bother my in the least. I have plugged my ATO into a smart plug to make water changes and gravel vacuuming easier as I can disable it while doing so. Hopefully people find this review helpful. 😊

Very easy to set up. No complex programming. It's not loud or annoying, but you can hear it. Very briefly, I forgot about it. Along with using to top off, this will be great to use when cycling my Axolotl tank. The price is good, helps when you are busy, but as with everything, you have to monitor it, and it does have an alert.

Maintaining the right water level in an aquarium is crucial, and this ATO makes it simple. Every aquarium loses water to evaporation, but in saltwater setups, that also means salinity levels start to climb. This system takes the guesswork out by automatically topping off the water, keeping both the level and salinity stable so fish and corals thrive. The design is compact and sleek—just 0.7 inches in diameter—so it doesn’t take away from the beauty of the tank. Setup was straightforward, with all the parts included, and it fits perfectly in rimmed or rimless tanks. I really appreciate the safety features. The QST protection gives peace of mind by monitoring refill times and preventing overfilling or pump damage if something goes wrong. Overall, this is a practical, space-saving, and reliable solution for anyone with an aquarium. It’s not just convenient—it’s a must-have for maintaining a healthy aquatic environment.

This worked really well till it didn't. The sensor started giving out after about 2 months. It would start filling and just not stop. It would drain my entire 5 gallon bottle into my tank, which luckily isn't enough to send my 75 gallon tank overflowing... But it'll just sit there trying to pump water non stop when the sensor is very obviously fully covered in water. I've come out in the morning to my tank overfilled with the pump running air for who knows how long, likely at least 2 hours straight. The sensor was not dirty. I keep it clean. I have cleaned it after it's malfunctioned and it would malfunction again later that day. I have bought a replacement sensor from another brand. Somehow the water pump hasn't burnt out so I'm still using that. The replacement is working so far, but I've only had it about a week. I'm sure that while it's a different brand, they're all from the same manufacturer, because they're exactly the same. Hopefully this one lasts at least a little longer than 2 months... In that 2 months I became very much dependent on this system, I have pothos growing out of my tank, and when the water evaporates too far, the roots get exposed to air, dry out, then I top up, and those dry roots rot and die. Since having the system, that has stopped, and my plants are doing better than ever. I really need this system to keep working 😭

Honestly one of the best purchases I’ve made for my aquarium, although I don’t use it for its intended purpose. I use if for water changes, putting the pump in my aquarium with the sensor off to the side, and the water goes into a bucket, and for refilling I unplug the sensor, move the pump to the bucket of new water, put the sensor in my aquarium as indicated in the instructions, and then plug the sensor back in. It is so, so, so much easier than getting my siphon started, stresses my fish out WAY less, and creates way less of a mess too. It obviously doesn’t work for vacuuming gravel, but it’s made maintenance on my aquarium so much less stressful, and freed up a decent chunk of time too.

Setting up a small reef tank in my living room, evaporation was disrupting my salinity stability, I'd lose 1-2 cups a day in summer. Picked up this ATO system and it's been running flawlessly for over a month now. It uses dual optical sensors, very accurate, no false triggers from waves or bubbles. When evaporation drops the level, the quiet submersible pump kicks in and slowly adds fresh RO/DI from my 5-gallon reservoir bucket (not included, but easy to connect with tubing). It adds the right amount in short bursts, keeping parameters steady, salinity holds at 1.025-1.026 without fluctuation. Installation was straightforward, mount the sensor bracket in the sump, drop the pump in the reservoir, route the tubing, plug in, and calibrate if needed. Pump is very quiet, no vibrations, and the whole system feels well-built for the with sturdy tubing and good connectors. No leaks after setup, highly recommend!

Ha funcionado muy bien

I bought this ATO for my nano saltwater aquarium and would not buy again. It failed twice in about 4-5 months. The magnet is not strong enough so any large turbo snail can push the sensor up, making the water level go up. Also, the glow of the light is annoying at night. Pay more money now for a good ATO with a strong magnet and a cover over the light sensor

Excelente producto muy buena precisión y fácil de instalar

Muy bueno el producto comple perfectamente con lo especificado