FZONE Aquarium ATO System, QST2.0 Auto Top Off Controller for Tanks

I've used the previous FZONE ATO, and this new QST2.0 version is a massive improvement. The biggest feature for me is the overfill safety protection. It already saved me from what could have been a disaster. Something happened in my overflow box that prevented water from making it back to the return pump section of my sump. The sensor was still exposed and calling for water, but instead of continuously pumping and flooding my floor, the ATO went into flashing alarm mode and shut itself down. What a lifesaver... and a carpet saver! I also really like the updated controller design. The lights are easier to see, and the button makes it simple to temporarily turn the unit on or off when working around the tank or moving equipment. It's much more convenient than the previous version. I still sometimes unplug it out of habit because old reefing fears die hard, but my confidence in this unit is growing quickly. So far, this has been reliable, easy to use, and clearly designed with real-world reef tank issues in mind. If you're considering an ATO for a saltwater tank, this newer version is absolutely worth it. Kudos to FZONE for making a good product even better. 👍🐠🌊

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!

Worked well for a week, went on vacation and when I came back it had stopped working and my aquarium water level was extremely low

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!

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!

Had this only for a couple of months the sensor that’s supposed to read the water level when it gets wet. It knocks out the whole system. How could a sensor that’s supposed to water get wet inside this is a piece of junk. Don’t waste your money.

I have it set up in a freshwater storage tank to top off a saltwater sump. It works ok to pretty good at best. I don’t necessarily trust it for a few reasons. Tends to put a little too much water. The check valve is crappy and trickles water after it turns off. And constantly goes into alarm saying it doesn’t have water when it’s sitting in a full tub of fresh water lol. I guess it’s better for the alarm to go off on a low water alarm then getting stuck open and overflowing the sump and flooding my office

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.

I’ve been using it for a couple of months now. Had a small issue with it inthe beginning, contacted the company and they were very helpful and kind, my problem was corrected easily the first try. Be sure to have the outflow water tube just above the water level in your aquarium and you’ll avoid my issue altogether. I find it makes water changes easier. I’ll be buying another for my other aquarium.