Red Sea ReefATO+ Reefer Upgrade Kit — 3-in-1 Smart ATO for REEFER Sumps

The Red Sea ReefATO+ Reefer Upgrade Kit is the same 3-in-1 system as the full ReefATO+ — auto top off, temperature monitor and leak detector connected to ReefBeat — in a version Red Sea offers to existing REEFER owners at a lower price.

How it differs from the full system

Red Sea describes it as a drop-in replacement for the stock gravity-fed float valve system of the REEFER: the sensor installs right where your float valve used to sit, in the bracket already built into the sump. That is why the kit does not include the magnetic mounting bracket of the full system — your REEFER simply doesn't need it. Everything else is there.

Our advice

Auto top offs have been around for years in this hobby. Red Sea did not invent the ATO — they took the concept, put their engineers on it, and genuinely improved it. If you already run a REEFER with the stock float valve, this kit is the cheapest way into the ReefATO+: same sensor, same pump, same alerts, without paying for a bracket you don't need.

What Red Sea improved

• Solid-state titanium probe level sensor (EC technology): no float, no moving parts. The probes tell whether the level is above, below or at the target point.
• Each fill lands within a precise 3 mm band, keeping water volume and salinity stable (Red Sea data).
• Backup probes that only react while the pump is running: normal level swings — roller filters, return pump off — never trigger false alarms.
• Automatic shutdowns: sensor disconnected, pump running too long, reservoir run dry, or leak detected.
• Built-in thermometer pre-calibrated to 0.1° with a full log and alerts.
• REEF-SPEC titanium probe leak detector (RO and seawater) that can even switch off ReefBeat-connected ReefRun pumps if a leak is found.

What's in the kit

• Water level and temperature sensor with the install clip for the REEFER float valve bracket
• 12 V DC variable-flow ATO pump (6–10 W, 300 lph / 75 gph, 2.5 m / 8' max head)
• Smart ReefBeat controller
• Leak detector
• 3 m (10') silicone tubing with tube holder and syphon breaker
• Power supply
• Not included: the magnetic sensor mounting bracket (full system only — unnecessary on a REEFER)

Saltwater aquariums only

Red Sea states that the ReefATO+ EC probes require the electrical conductivity typical of seawater. This kit is not suitable for freshwater aquariums.

Complete your setup

• Full Red Sea ReefATO+ 3-in-1 — the version with the magnetic bracket, for tanks that are not REEFERs.
• Red Sea ReefCan 18 & 40 — the vertical reservoir built to hold the ReefATO+ syphon breaker.
• ReefATO+ replacement sensor — genuine part R35622.

Why buy your kit at ReefSolution

We are an authorized Red Sea dealer. Our team in Laval runs the ReefATO+ on its own systems and can walk you through the install in your REEFER. Shipping across Canada.

Frequently asked questions

What is the difference between the Reefer Upgrade Kit and the full ReefATO+?

It is the same 3-in-1 system. The kit simply omits the magnetic sensor bracket: on a REEFER, the sensor clips into the bracket of the stock float valve, which this kit replaces. Red Sea offers it at a lower price for REEFER owners. For any other tank, get the full system.

Does this kit work in freshwater?

No. Red Sea states the sensor needs the electrical conductivity of seawater: this is a saltwater-only kit.