

💧 Keep your reef thriving with effortless precision!
The Useek Auto Top Off (ATO) System is a compact, smart water level controller designed for both saltwater and freshwater aquariums. Its nano-sized sensor and QST technology ensure precise, real-time water top-offs, preventing salinity fluctuations and protecting aquatic life. Easy to install and backed by a two-year warranty, it’s the perfect upgrade for aquarium enthusiasts seeking stability and convenience.





| ASIN | B0CFVWDKMC |
| ASIN | B0CFVWDKMC |
| Best Sellers Rank | #8,177 in Pet Supplies ( See Top 100 in Pet Supplies ) #11 in Aquarium Water Pumps |
| Brand Name | Useek |
| Color | Blue |
| Customer Reviews | 4.0 4.0 out of 5 stars (619) |
| 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 |
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.
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.
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**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.
J**R
Simple and reliable
Very easy to set up and works as expected. It keeps the water level stable, which really helps prevent sudden changes. The sensor works well and I haven’t had any issues so far. For the price, it’s a solid option. I recommend it
B**E
Effective and Affordable
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.
J**.
A much needed accessory for my tank.
Sensor seems to work flawless. Easy setup with detailed instructions. I got a fault light and realized the bubbler was too close. I moved it and no problem since. This helps take a little work off my plate during these dry winter months.
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.
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
4 days ago
1 week ago