?unique=9ecd6e9)
Octo FW110 High Amperage Float Switch (OPEN BOX)
SKU: OB-CV-FW110
- The Reef Octopus FW110 is a 5-amp high-amperage float switch for aquarium water level control applications.
- It works in high water or low water level configurations by inverting the barrel float to reverse the trigger direction.
- It can handle multiple pumps simultaneously up to a combined draw of 5 amps on a single 6-foot grounded power cord.
- The direct-plug design lets it control pumps without a separate controller, making it usable as a standalone safety device.
Reef Octopus
Globally trusted for premium protein skimmers and pumps, engineered in-house for unmatched reef filtration performance.
-
Open box: new, inspected, ready to use
-
FREE Shipping on orders over $75.00
-
Backed by a 90-Day Warranty
Aquarium Float Switch for ATO, Skimmer Protection, and Pump Shutoff
The Reef Octopus FW110 High Amperage Float Switch is a probe-style water level switch rated at 5 amps. It plugs directly into an outlet and controls whatever is plugged into its output cord, with no controller or additional hardware required. The FW110 handles up to 5 amps of combined load, which is enough to run multiple smaller pumps simultaneously from a single switch.
The switch works in two orientations. With the barrel float in its default position, the switch triggers on high water (shuts off or activates when the water level rises to the float). Remove the retaining ring, flip the barrel float upside down, and it triggers on low water instead, making it usable as an ATO activation switch for a top-off pump. This single mechanical adjustment covers the two most common float switch applications in an aquarium setup.
Key Features:
- The 5-amp rating supports multiple pumps on one switch, with a combined load up to 5 amps.
- Reversible barrel float switches between high-water and low-water trigger modes without any tools — remove the retaining ring and flip the float.
- Includes a 6-foot grounded power cord for flexible placement in sump cabinets or equipment stands.
- Probe-style design for precise, reliable water level detection.
- No controller required; plugs directly into a standard outlet and operates standalone.
- Usable for skimmer overflow protection, ATO top-off control, or pump dry-run prevention.
Ideal For:
- Hobbyists who want a simple, no-controller float switch to cut power to a return pump or ATO pump at a specific water level.
- Reef and saltwater setups using a protein skimmer collection cup or sump overflow application where a high-water shutoff is needed.
- Anyone running a basic ATO system who wants a low-water float switch to activate a top-off pump without a dedicated ATO unit.
Pro Tips:
- Use two switches for a belt-and-suspenders ATO setup. One FW110 set to low-water activates your top-off pump. A second set to high-water cuts it off as a backup. This gives you both trigger and safety shutoff without needing a dedicated ATO controller.
- Keep the probe vertical and free from obstructions. The barrel float needs to move freely to trigger reliably. If the float gets fouled with salt creep or contacts the tank wall or equipment, it can fail to trigger. Clean the probe periodically and make sure it has clearance on all sides.
- Check your pump's amperage draw before wiring multiple pumps. The 5-amp limit is the combined total. A typical small ATO pump draws well under 1 amp, but larger return pumps can draw 2-3 amps. Add up the nameplate amperage of everything you intend to plug in before connecting.
What's Included:
- FW110 High Amperage Float Switch with probe
- 6-foot grounded power cord (integrated)
Specifications:
- Switch Rating: 5 amps maximum (combined load)
- Trigger Modes: High-water or low-water (reversible via barrel float inversion)
- Cord Length: 6 feet (grounded)
- Switch Style: Probe-style barrel float
- Voltage: 110V/120V AC
WARRANTY
CoralVue, Inc. hereby guarantees this product to be free from defects in material and workmanship for a period of:
- 90-days
- Warranty is activated on the date of purchase.
This Standard Limited Warranty applies and is limited as follows:
- To the product only as long as it remains in the possession of the original purchaser.
- To the product that has not been subject to accident, misuse or abuse.
- To the product that has not been modified, altered, defaced, or had repairs made or attempted by other than CoralVue, Inc.
- That CoralVue be immediately notified in writing within ten (10) days of first knowledge of defect by owner or his agent.
- That CoralVue, Inc. shall be given first opportunity to make any repairs, replacements or corrections to the defective construction within a reasonable period of time.
- Under no circumstances shall CoralVue and/or the Manufacturer be liable by virtue of this warranty or otherwise for damage to any person or property whatsoever for any special, indirect, secondary or consequential damages of any nature however arising out of the use or inability to use because of the product defect.
Instructions:
Low-water configuration (ATO activation — turns on at low water level):
- Remove the retaining ring from the barrel float.
- Flip the barrel float upside down and replace the retaining ring.
- Position the probe at the desired minimum water level in the sump or display tank.
- Plug the top-off pump into the FW110's output cord.
- Plug the FW110 into a standard grounded outlet. When the water drops to the float, the switch will activate the connected pump.
Note: Do not exceed 5 amps of combined load on the output cord. Check the nameplate amperage of all connected devices before use.