Mounting and Hanging Reef Lights — Practical Guide for UK Setups

Getting the Light in the Right Place

Mounting height and method matter more than most reefers expect. Too low bleaches the corals underneath while leaving edges dark. Too high loses intensity. Wrong angle spills light into the room. The method also affects maintenance access.

Mounting Options

1. Tank-Mounted Arms / Brackets

Most reef LEDs come with or offer optional mounting arms that clamp or rest on the tank rim.

Pros: No drilling, easy height adjustment, designed for the light, moves with the tank. Cons: Arms above the tank can obstruct access, weight limits on tank rims, and some are overpriced. Best for: Most standard setups, especially in rental properties.

2. Ceiling Hanging Kits

The cleanest look — light floats above the tank with nothing obstructing access below.

What's needed: A ceiling hook screwed into a joist (use a stud finder, about £15 from Screwfix), stainless steel hanging cables with adjustable clamps, and cable management clips or trunking.

Pros: Best aesthetic, full tank access, easy height adjustment. Cons: Requires ceiling drilling, not ideal for rentals, joist positioning may not align with the tank.

Hanging height: Start at 20–25cm above the water surface. Raise to 30cm+ if PAR is too intense at the top; lower if more intensity is needed.

3. Wall-Mounted Arms

A bracket on the wall behind the tank with an arm extending over it. Works well for peninsula-style tanks.

4. DIY Light Rails / Frames

Aluminium extrusion (like 2020 V-slot) that sits over the tank supporting multiple lights. About £30–50 for materials on a 120cm rail. Best for: Multi-light setups with three or more LEDs.

Practical Tips

• Height affects PAR distribution significantly. Moving a light up 5cm reduces peak PAR but improves spread.
• Plan for maintenance access. Quick-release carabiners allow unhooking and swinging the light aside in seconds.
• Check weight on arms. A single Hydra or Radion weighs about 2.5kg — on a long arm, the leverage at the clamp point is significant, especially on rimless tanks.
• Manage light spill. A simple shield on the room-facing side makes a big difference for living room setups.

Browse reef lights and mounting accessories from UK sellers — mounting arms and hanging kits from previous setups are commonly available used.

How have you mounted your lights? Any DIY solutions worth sharing?