Neptune Systems Leak Detectors

The LD-1 Leak Detection Probe is a low-profile sensor designed to detect the presence of water in tight spaces. Compatible exclusively with the Neptune Systems FMM Module, the LD-1 allows your Apex Controller to instantly notify you if a leak or overflow is detected.

Its slim design makes it ideal for placement under carpets, behind aquarium cabinets, or in other hard-to-reach areas where standard leak detectors (like the LD-2) may not fit.

Note: The LD-1 is only compatible with the FMM Module. It is not compatible with the older ALD module.

Key Features

• Low-profile design for narrow or hard-to-access spaces

• Works with Neptune FMM Module only

• Sends instant alerts through Apex Fusion when water is detected

• Suitable for placing under carpet, cabinetry, or behind tank stands

• Ideal for detecting:

  • Floor spills

  • Sump overflows

  • Skimmer cup overflows

  • RO/ATO system failures

Use Case Recommendations

Choose the LD-1 when:

• Space is limited (e.g., under cabinetry or tight filtration areas)

• You require detection beneath carpet or mats

• You want discreet leak detection with minimal footprint

If you do not have space constraints, consider the LD-2 for a larger detection footprint.

Compatibility

• Compatible with: Neptune FMM (Fluid Monitoring Module)

• Not compatible with: ALD (Advanced Leak Detection) module

What’s Included

• 1x LD-1 Low-Profile Leak Detection Probe

Requires FMM Module and Apex Controller (sold separately).

The LD-2 Leak Detection Probe is a full-size water sensor designed to provide early detection of leaks, overflows, or spills in and around your aquarium system. When connected to the Neptune FMM Module, the LD-2 integrates with your Apex Controller, allowing you to receive real-time alerts via Apex Fusion if water is detected.

Its weighted, flat-bottom design ensures reliable placement on a variety of surfaces, from inside cabinetry to bare flooring.

Note: The LD-2 is only compatible with the FMM Module. It is not compatible with the ALD module.

Key Features

• Designed for use with the Neptune FMM Module

• Weighted base ensures secure, flat placement

• Ideal for flat, hard surfaces (e.g. flooring, sump stands, skimmer lids)

• Triggers alerts through Apex Fusion when water is detected

• Can be used in multiple high-risk areas including:

  • Under the aquarium

  • Inside cabinetry

  • Under sump equipment

  • On top of skimmer lids

  • Around RO or ATO systems

Use Case Recommendations

Choose the LD-2 when:

• Space is available and you want broad surface coverage

• Installing on hard, flat surfaces like stand bases or floors

• Monitoring general tank or equipment overflow areas

If space is limited or you’re working around carpet or tight clearances, consider the LD-1 Low-Profile Leak Detector instead.

Compatibility

• Compatible with: Neptune Systems FMM (Fluid Monitoring Module)

• Not compatible with: ALD Module

What’s Included

• 1x LD-2 Full-Size Leak Detection Probe

Requires FMM Module and Apex Controller (sold separately).