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

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 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!

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 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.

Let me start by saying this, I was skeptical due to some of the reviews about tanks overflowing. Please read the instructions and simply follow them!! I have a 80 gallon aquarium and needed an ATO asap. Followed the instructions and this product delivers!! Easy to set up, super quiet when operating. It’s small so it’s not an eye sore. If you follow the instructions… it fills even a large aquarium perfectly!!! For the money, it’s cheaper than the alternatives!! The pump does shut off when it’s out of water or reaches desired level. Just please follow the instructions.

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.

It’s an excellent product, especially for those with multiple aquariums. You can trust it to continuously fill the tank and maintain the desired water level. It’s very quiet and helpful. The filling stops as soon as it touches the sensor.

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.