






💧 Keep your reef flawless—automate water top-offs like a pro!
The Useek Auto Top Off (ATO) system is a sleek, compact solution designed for both saltwater and freshwater aquariums. Its nano-sized sensor and smart QST technology ensure precise water level maintenance, preventing salinity fluctuations and protecting aquatic life. Easy to install and backed by a 2-year warranty, this system offers reliable, quiet operation that fits seamlessly into any tank setup.





| ASIN | B0CFVWDKMC |
| ASIN | B0CFVWDKMC |
| Best Sellers Rank | #7,437 in Pet Supplies ( See Top 100 in Pet Supplies ) #13 in Aquarium Water Pumps |
| Brand Name | Useek |
| Color | Blue |
| Customer Reviews | 4.0 4.0 out of 5 stars (642) |
| Date First Available | May 15, 2023 |
| Date First Available | May 15, 2023 |
| Included Components | Pump |
| Item Package Dimensions L x W x H | 6.46 x 6.34 x 2.68 inches |
| Item Weight | 0.4 Kilograms |
| Item model number | AT-200 |
| Item model number | AT-200 |
| Manufacturer | Useek |
| Manufacturer | Useek |
| Material | Acrylonitrile Butadiene Styrene (ABS) |
| Model Name | Blue-1 |
| Package Dimensions | 6.46 x 6.34 x 2.68 inches; 14.07 ounces |
| Specific Uses for Product | Reef and Freshwater Aquariums |
| Style | Modern |
| Target Audience Keyword | fish |
| Warranty Description | 1 |
R**A
Should have purchased sooner
I've had this saltwater tank for awhile and I should have purchased this auto top off so much sooner. This unit really has made maintaining my fish tank so much easier. The size of this is less than an inch and it doesn't stick out in my tank either. It fit perfectly on the rimless setup without taking up a lot of space. Setup was super easy and everything I needed to get this running came in the box. Overall, it took me about 15-20 to have this setup and ready to use. I really like the safety feature it has that monitors and refills my tank with an auto shut off. I have left my house for the weekend and came back to absolutely no mess but my tank maintained its level of water. Plus, once its attached to my tank, it doesn't fall off either, very sturdy. Plus the other thing I noticed is that this whole thing doesn't make any noise. All I hear is running water every now and then and that's it. There have been no sudden swings of stressing my fish out either.
T**E
Perfect!
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.
A**R
Buyer beware! Designed to break. Low grade disposable product.
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.
S**M
Works for water changes too
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.
J**N
Not indestructible but worth the price for simple tanks
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
S**K
Works great
Easy to set up and works great. It keeps my tank’s water level right and the pump is quiet. Everything feels well made and seems reliable. Definitely a nice upgrade from doing the top offs by hand.
K**E
Ok for the price. Don't expect it to last too long.
I don't want to completely diminish this product. It's not hard to assemble or use. It's small and indiscreet if you can cover the light of the sensor. For the price you pay it's decent. I do worry that the sensor maybe isn't as water proof as it needs to be. It will likely stop working before a year. I have purchased two. One is still going the other has a solid red light when powered on and in place and will no longer operate. I have tried using both distilled water and 99% alcohol to clean the sensor and it has not worked. I even soaked the sensor in alcohol overnight. The only other thing I can think to try is maybe cleaning the pump. I'm pretty certain it is finished though. If you can, try to place the unit and disturb it as little as possible. I think when I removed it recently and let it dry that was what ultimately did it in. Simple set up and mechanism. Decent price and design. Poor longevity.
D**S
Easy setup maintenance free
Used this on my 180 gal salt water tank. Works as advertised. I have no complaints. Install in minutes.
J**.
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!
A**R
Ha funcionado muy bien
R**K
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
R**O
Excelente producto muy buena precisión y fácil de instalar
U**O
Muy bueno el producto comple perfectamente con lo especificado
Trustpilot
1 week ago
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