Aquarium ATO System, QST2.0 Auto Top Off Controller for Tanks | Smart ATO system with precise controller for saltwater and freshwater aquariums, maintaining stable water levels

I can honestly say this ATO system has exceeded my expectations. I didn’t realize how much I needed an automatic top-off system until I installed this one. One of my favorite features is the sleek external controller. It gives me clear status indicators and easy controls without adding unnecessary lights or clutter inside the aquarium, keeping the display clean and distraction-free. Installation was quick and straightforward. For a cleaner, more finished appearance, I drilled a 3/8-inch hole in the back of my standby water reservoir to route both the water tubing and the DC pump cable. The result looks professional and keeps everything neatly hidden. Best of all, no more water lines from fluctuating water levels and no more manually topping off the tank every day. It’s one of those upgrades that quietly makes aquarium maintenance much easier. Thanks for a great product, FZONE!

Great little ATO. It is really tiny! Easy to setup, comes with everything you need and it has been rock solid now for several weeks. It is very quiet while operating and I also appreciate the one-click resume, when you res runs out of water, this beeps and turns red, click the button after filling up your res and it resumes normal operation. I have never had another ATO with this feature. Full tank shot of my 120 gallon soon to be planted (just finished cycling) and sump where you can see just how small the sensor is (bottom right) and controller is (top middle w/ inkbird temp controller next to it for size comparison)

Absolutely horrible. I was wary to purchase this and I should have trust my instincts. Within two weeks it dumped the entire reservoir into the tank dropping salinity (fortunately did not lose any animals). It went into alarm status when the reservoir was emptied. Also lucky that it did not overflow the tank as the reservoir had maybe half a gallon. I should have sucked it up and bought a tunze.

Perfect ATO System - Set It and Forget It! The FZONE Aquarium ATO with Controller has been one of the best upgrades I’ve made to my tank. Setup was incredibly straightforward, and the controller feels solid, accurate, and reliable. The optical sensor detects water levels perfectly, and the pump tops off smoothly without any noise or delay. I love that I no longer have to worry about daily evaporation and my water level stays stable, and my fish are happier than ever. The safety features give great peace of mind, and the build quality is way better than I expected for the price. If you’re looking for a dependable, hassle-free automatic top-off system, the FZONE ATO is absolutely worth it. 100% recommend!

I’ve been using the FZONE ATO with QST2.0 Controller for a few months, which has completely streamlined my tank maintenance routine. Right out of the box, I was impressed by the build quality — sturdy components, well-packaged, and clear instructions. Setup was a breeze. It took under 20 minutes to install and calibrate everything. The QST2.0 controller is the real star here. It’s smart, responsive, and offers a level of precision that gives me total peace of mind. The sensor is extremely accurate and doesn’t require constant tweaking like some cheaper models I’ve used in the past. I particularly appreciate the fail-safe features — if something goes wrong (like the reservoir running dry), the system alerts you and shuts off automatically to prevent any disasters. I’ve noticed a significant improvement in the stability of my tank's salinity and water levels since installing this ATO. It's super quiet during operation, and the included tubing and bracket are both high quality and easy to position just right. I had an issue months later with the sensor accuracy, contacted Customer Service and they replace the part immediately! Thanks Cheryl! If you're on the fence, don't hesitate — the FZONE is worth every penny. Highly recommend!

It works but everything i am out of town which is 3 times since purchase 2 out of 3 times i came back to red light on the controller. Kind of defeats the purpose.

So far I have been very impressed with this ATO. Operation is whisper quiet and the controller makes it easy to disable for water changes and the sensor is accurate. I can attest to it's ability to stop automatically if pump is active for too long after my sea hare went across the tank's overflow weir when I was not far away. I heard the alarm and checked to find the weir partially blocked and the return pump chamber low. Once the hare had moved on, I just pressed the button on the controller and it reset it self. On another note, when people complain about overflows, I wonder if the sensor just needs to be cleaned of salt/mineral buildup.

I travel and really don't trust anyone to keep up with my salter water aquarium and the reservoir to keep my auto top off full. I purchased this use in my backup reservoir in hopes of it keeping my main reservoir full at all times, for at least 6 days. It worked like a charm! I'm so glad I got this, and especially for the money! ! It's quiet, and simple to set up. If it is empty, the red light comes on to turn off the pump. When you're ready to fill it again, you just push the red button, and the pump turns back on. Easy!

Avendo in casa diverse vasche nel periodo estivo mi trovo a dover rabboccare l'acqua evaporata, se la vasca è piccola ci si sta dietro ma quando questa è grande diventa un vero problema. Per tale scopo ho acquistato questo sistema di rabbocco automatico, l'ho testato appena arrivato simulando una evaporazione minima e devo dire che dopo che l'acqua è scesa di pochi millimetri, il sistema ha attivato la pompa per ristabilire il corretto livello, ho ripetuto diverse volte questa prova e il sensore è sempre intervenuto in modo preciso. La pompa l'ho immersa in una tanica da 20 litri essendo piccola per mia fortuna è passata dal foro del tappo, la pompa riesce a spingere l'acqua tranquillamente nella vasca nonostante sia a livello pavimento. Nella confezione c'è tutto il necessario all'installazione, non manca proprio nulla, quindi che dire il prodotto è perfetto, completo e allo stesso tempo funziona bene. Dimenticavo lo utilizzo anche per i cambi settimanali d'acqua così non porto più su le taniche e fa tutto lui in automatico e la mia schiena ringrazia.

It comes neatly packed, everything feels high quality. Setting up is simple thanks to the clear, well organized installation manual. Whether you need a temporary solution for holidays or a permanent fixture, this top off system delivers. It features a convenient one press pause button for water changes and operates in near silence.

No funciona bien. Se suspende a cada relleno aún teniendo agua el depósito. Debes estar muy al pendiente a que no se suspenda (ponerse en rojo la luz), es lo mismo a estar rellenando en modo manual. Tendré que comprar otro que sea seguro en su funcionamiento.

Diese Nachfüllautomatik funktioniert tadellos schon seit Wochen. Keine Kritik notwendig.

Installation facile avec un manuel clair (même si en anglais, on s’y retrouve rapidement). Les deux capteurs optiques fonctionnent parfaitement et permettent de maintenir un niveau d’eau stable dans l’aquarium, avec une sécurité fiable pour éviter tout débordement. Le système est silencieux, la pompe est efficace et le boîtier est simple à utiliser (un appui long pour l’initialisation, très pratique). Bon rapport qualité/prix, je recommande pour tout bac planté ou récifal qui a besoin d’un niveau d’eau constant.