FZONE ATO with Controller, QST2.0 Auto Top Off System for Saltwater Aquarium & Freshwater Aquarium

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!

This is my second ATO from FZone. The other one is the V1 from FZone. Both work great but this new V2 blue version has alot of new things I really like. It has a button now for control over the fill, so you can set it all up and manage your wires before ever running the thing. It also has an alarm for issues now that only beeps a few times but all the lights are on the controller so its not in the tank. If Evaporation is an issue and your looking for a solution Give this a try. Works great keeping the tanks filled without haven to worry about over flow. I also like the new blue color, the green was nice but the blue looks better IMO.

This seemed to be working fairly well until it went crazy and dumped 5 gallons of freshwater into my tank. That led to an overflow in the sump and I suddenly had a lake in my office. Fortunately the tank is new, so there were no corals or livestock in the tank. I will be going back to doing manual top offs. I recommend that you stay far away from this.

Great quality for the price, it seems well made. This is great for my small aquarium. I like that it is small, fits any application. Magnet is very strong. I like that it has indicator light. Will buy again.

Received the product yesterday and it is easy to install and use. Single button to set up and colored LEDs show status easily. Seems if if it needs to be reset each time it loses power, but that is a matter of pressing one button. However, it will not refill your tank until it is reset.

Picked this up to keep the freshwater tank stable while I was out of town. It was supposed to be temporary. That was months ago, and I haven’t unhooked it since.It makes water changes stupidly easy—just fill a bucket, and the pump quietly handles the rest. No siphon, no mess, no babysitting. It moves water into the tank smoothly without kicking up substrate or stress.The safety features are solid. It doesn’t overfill, period. I trust it to stop if something’s off. The downside: during water changes, it constantly thinks something’s wrong—like the hose popped out or the tank’s leaking. It’ll pause, beep, and make you reset it... sometimes multiple times. Annoying, but it's just doing its job.

5/9/25 - I’ve been contacted by the seller and offered to review the updated unit to see if it resolves my issue. Customer service appears to be excellent. Will report back on experience. Moving to 3 stars during review.I wanted to love these and was so excited that I found ATOs for a third of what they charge at the fish store. I have three of these and have never once made it past 8hrs without them alarming and shutting off. Complete waste of money and now I get to go spend all the money I was trying to save.

I've been using this ATO for several months now and it's working perfectly. The included controller is a huge plus because you can 'pause' the ATO when you're doing water changes or turning off pumps and the water level temporarily changes.The LED light on the controller is pretty bright but I solved that by putting it inside a protective power strip box.Wipe off the sensor when you're doing water changes to ensure a long service life.