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

I’ve been using this auto top-off system for my aquarium and it’s honestly been a game changer. It keeps the water level consistent without me having to constantly check and refill, which saves a lot of time and stress. The setup was pretty straightforward, and I like how compact it is—it doesn’t take up much space or ruin the look of the tank. It works well for both reef and freshwater setups, and I’ve noticed my tank stays much more stable since using it.

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've now purchased 3 times. All 3 of these are absolutely garbage. They work for ruffly 1 to 6 months and then ultimately fail. Reviews say it's great, but notice none of the reviews mention "Years of use". Longevity wise, this gets 1 out of 10. Waste of money. The pump is a 2 out of 10. It's slow, small and breaks easily. It's the kind of pump you'd expect to pay about $1 for. The sensors are NOT water proof and in fact the sensors will take in water and then create a film inside that destroys the sensor. All in all, this is an epic waste of money. Amazon should be ashamed to sell this product, as it's designed to break and you will need to replace it again and again and again. Quite frankly, I'd like my cash back. This is a scam product in which I have 3 of. 3 is enough to prove a point. If the seller or anyone at Amazon would care to interject, maybe we could establish some accountability. For this product, there is none. Buyer beware. This is a disposable product with a shirt lifespan. Absolutely rubbish.

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.

Works as intended, and is great for the price. It only failed me once and of course it was while I was away for a week. It lasted 2 years and the salt creep broke the seal on the optical sensor and water got in. Fried the sensor. But for $40, Id say it exceeded my expectations. I wouldnt use this on my big tank with expensive stuff, but a smaller tank is perfect! I will just buy a replacement and maybe try to reinforce the seals on the new one. If only they sold the sensor separately

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 😭

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