As more and more ATOs (Automatic Top-Offs) become available, it is becoming increasingly difficult to decide which is the best choice.

The latest from CoralVue is the AutoAqua Smart ATO, an amazingly compact unit packed with great features that will put it at the top of many hobbyists’ holiday shopping lists.

The first thing I noticed opening the box is how small the sensor and pump are. As seen on many of the CoralVue advertisements, the sensor/controller is barely bigger than a golf ball. The low-voltage DC pump is also nice and small, so it will easily fit into the common 5 gallon water jug many hobbyists use as ATO reservoirs. Also included are 6-feet of tubing and a handy universal holder that can mount on to a rim up to ¾” thick (in horizontal or vertical position). This complete package gets you up and running without having to purchase any additional parts or accessories.

The most unique feature of the Smart ATO package is definitely the diminutive and advanced sensor/controller. Just about all ATOs include separate sensor(s) and bulky controllers—which require additional wires and extra space for installation. The Smart ATO combines the two components in an amazingly small package that easily mounts to your tank or sump via magnets. The optical sensor is very precise and features an Auto-Feedback Security Technology (AFS) with no moving parts that can fail. The only part that goes inside your sump or tank is the magnet with an optical lens so there are no electronics or valves in/near the water.  

Installation is just about as easy as it gets:
  • Attach the tubing to the pump and place the pump into your reservoir
  • Use the bracket to secure the tubing outlet to your tank or sump where the top-off water will be dispensed.
  • Install the sensor/controller at the desired water level
  • Plug the pump and power cables into the sensor/controller
  • Plug the power adapter into your wall outlet and you’re done!
Works on glass up to 1/2" thick... as advertised!
For the technical guys… the AFS algorithm is actually quite simple and should be very effective. For over-vill security, the system will sound off an audible alert and the Red LED on the controller will illuminate if the filling time is more than three time longer than the previous fill.

For example, if the pump typically takes 1 minute to fill, the AFS will trigger if the filling takes more than three minutes (if your top-off reservoir were to run dry or something caused the sensor to not detect the water is already full).

For non-fill security, the AFS will sound an alarm and flash the blue LED if the amount of time between top-off is more than three times the previous. For example, if the system typically tops off the aquarium every 10 hours, the AFS will trigger if the top off does not initiate for more than 30 hours (if the lens were misaligned, for example, or if there were algae build-up on the lens causing a false reading).

With its innovative design and features, the AutoAqua SmartATO from CoralVue is sure to be a hit. With a complete package price of only $149.99, it definitely makes the competition for the “best” ATO tougher than ever!