Meridian OHM Optics - Reef Breeders

OHM (Ocular Holo Matrix) optics are the interchangeable lens panels that control how the Reef Breeders Meridian spreads and drives its output. Each optic sits over one full 24-LED matrix and determines the beam angle — and by extension, how wide the light fans out and how deep usable PAR reaches into the water column. Changing optics does not require specialized tools or professional service; a standard number 2 cross-head screwdriver and 10 to 30 minutes is all that is needed, and swapping them does not void the Meridian warranty.

Three beam angles are available. OHM Focus narrows the beam to 45°, concentrating output into a tighter footprint and carrying light down to 48 inches (120 cm). It is the right choice for deep tanks, for corals positioned on the sandbed, or for fixtures mounted well above the waterline. OHM Balance at 90° is the standard spread that ships with every Meridian — it provides an even, well-blended field suitable for the majority of reef tank dimensions and depths down to 36 inches (90 cm). OHM Encompass opens to 110°, pushing light further front to back and reducing shadowing between coral colonies, making it best suited for wider or shallower tanks up to 24 inches (60 cm) deep.

Because each optic maps to its own matrix, different spreads can be run simultaneously across a single fixture. A Meridian 35, for example, could use Balance or Encompass over a central rock structure for broad coverage while running Focus on the outer two matrices to reach deeper into the sandbed on either side. The number of optics a fixture accepts scales with its size: one optic for the Meridian 11, up to five for the Meridian 63.

One practical note on OHM Focus: it concentrates output significantly, so placing it over raised rockwork can produce very high PAR at shorter distances. Dial back intensity and allow corals adequate time to acclimate before running at full power. Reef Breeders publishes a detailed installation guide covering the swap process, how to distinguish the three optics from one another, cleaning, and common questions.