• Solid-state level sensing — a titanium probe reads water level electronically, with no float or moving part to jam or stick.
• Built-in thermometer — the same probe reports tank temperature to the ReefATO+ controller and app, accurate to ±0.1°C.
• Fail-safe backup probe — a second shutoff point roughly 2.5 cm above the primary stops the pump if the main probe misreads, rather than letting it run on.
• 3 m cable — long enough to reach from most sump corners to the controller without an extension.
• Genuine Red Sea part — factory-matched to the ReefATO+ controller's calibration; the current hardware revision is R35622-V3.

This sensor fits the Red Sea ReefATO+ — the current "3-in-1" top-off, thermometer and leak-detector unit. We can't confirm from Red Sea's published material whether it's backward-compatible with earlier hardware revisions of the ReefATO+ controller sold before this listing's V3 revision. If you're replacing a sensor on an older unit and you're not sure it will pair correctly, check with us before ordering rather than guessing.

One sensor probe on its 3 m cable, ready to plug into the ReefATO+ controller. The mounting bracket and corner-mount magnets are sold separately.

• Suitable for: replacing a ReefATO+ sensor that has failed, drifted, or is fouled beyond a clean.
• Not suitable for: any top-off controller other than the Red Sea ReefATO+, or as a stand-alone level alarm without the ReefATO+ base unit.

Genuine Red Sea part R35622, current hardware revision V3 — matching the barcode on this listing. Fits the Red Sea ReefATO+ system. Related spares sold separately: the ReefATO corner mounting bracket and the external corner-mount magnets. Red Sea has not published a supersession note for this part.

Wipe the probe face during your weekly maintenance. A film of algae on the tip is the most common cause of an ATO that tops off late or reads temperature inaccurately.

Disconnect the ReefATO+ from mains power before removing or replacing the sensor. The probe itself is designed to sit in water; the controller and power supply are not.

• Red Sea ReefATO Corner Bracket — needed to mount this sensor vertically in a non-Red Sea sump.
• Red Sea ReefATO+ System — the full controller this sensor plugs into.
• Red Sea ReefCan 18L — a top-up reservoir sized for ReefATO+ systems.

Covered by our standard returns process for faulty goods, in addition to your rights under Australian Consumer Law. Standard freight.

How do I know the sensor needs replacing, rather than just cleaning?

Clean the probe face first — algae film is the most common cause of a late or early top-off. If cleaning doesn't fix it, or the temperature reading has drifted, the sensor itself needs replacing.

Does this include the mounting bracket?

No. This listing is the sensor probe only. The corner bracket and magnets are sold separately.

Will this work with an older ReefATO+ controller?

It's the current V3 hardware revision. Red Sea hasn't published cross-revision compatibility, so if you're unsure, ask us before ordering.

Can I use this with a sump that isn't made by Red Sea?

Yes — mount it with the corner bracket and magnets (rated for glass up to 12 mm) rather than clipping it to a Red Sea glass triangle.