NOTE: the version 4 now incorporates an updated sensor which is slightly larger than the original shown in the video, there are no difference's other than physical size!
NO SENSOR MAINTENANCE REQUIRED!
- sensor cable length 40cm (designed to be positioned alongside the controller-we do not advise extending the cable length)
suitable up to 9mm glass/acrylic, clear or not clear
overseas shipping available
The ATU-PRO4 has all the same safety features of the ATU-PRO3 - the difference is in the sensor type, its outside the aquarium not in!
2 year sensor guarantee!
ATU4 is pre-wired and the unit is ready to use - includes:
- The programmable controller
- Supplied with sensor and mount
- pump
- A 2amp power supply
- 2 metres small bore pipe w/hook outlet
- full installation guide online
The Reefloat Auto Top Up (ATU) is highly recommended by marine hobbyists and reefing communities for its built-in safety features, anti-wave technology, and industry-leading customer support. Unlike standard ATUs, its standout feature is a programmable backup timer that automatically cuts power to the pump if it runs longer than your specified threshold, preventing accidental aquarium flooding or reservoir dump disasters.
Pro 3 vs. Pro 4: Which should you choose? The Reefloat ATU kits come pre-wired and ready to use out of the box, with the core difference being the sensor type:
ATU-Pro3: Utilises an infrared/optical sensor that sits inside the tank or sump. It provides a clear visual indicator of the water line but requires occasional cleaning to remove salt creep or algae.
ATU-Pro4: Utilises an external capacitive sensor that reads the water level directly through the aquarium glass. Because it is positioned entirely outside the tank, it requires zero maintenance and won't get fouled by snails or slime.
Key Features Fail-Safe Programming: Allows you to set a maximum run time of 5, 10, 20, or 60 seconds. If a sensor fails or jams, the pump shuts down, flashes an LED, and triggers a loud audible alarm
Anti-Wave Delay: Features a built-in 3-second delay. The water level must remain consistently low for 3 full seconds before the pump kicks in, preventing constant on/off cycling caused by wavemakers or hands in the tank. High Head Height: Included 12V DC low-voltage pump can handle up to a 3m head height, easily pushing water from a reservoir tucked away under the stand.
Community Verdict -Hobbyists on popular forums like Ultimate Reef heavily favour the brand. While components like pumps can naturally wear out over several years, the brand's after-sales support is widely considered the absolute best in the UK market for troubleshooting and fast replacement parts
BONUS - Memory - that preset time you set up stays unless you reprogam, it is not lost on power failure!
Specifications
- sensor - capacitive
- sensor cable length 40cm (designed to be positioned alongside the controller-we do not advise extending the cable length)
- water level variance - less than 0.5mm
- voltage - 12v DC
- alarm - visual and audible programmable 5-60 seconds, pump auto cut-off on alarm
- pump - 12v DC with up to 3m head height
- anti-wave - 3 second delay on pump activation
- sensor mount - custom (exclusive)
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