How much

How much light for a 120 gallon?

Pre-calculated for the 120 gallon (48 × 24 × 24 in · water volume ≈ 108 US gal).

By scenario

ScenarioAmount
SPS-dominant reef

200–400 µmol/m²/s PAR

~161 W of modern reef LED. Examples: AI Hydra 32/64, Radion XR15 Pro G6, Reefi UNO/Lumi.

Mixed reef (LPS + some SPS)

75–150 µmol/m²/s PAR

~108 W LED. Examples: AI Prime 16HD, Kessil A360X, Reefi UNO Black.

Softie / zoa / mushroom tank

50–150 µmol/m²/s PAR

~65 W LED — softies often color up better at lower PAR.

Fish-only with live rock (FOWLR)

Any visible white light

Aesthetic only. Hobby AC LED strips at $50–100 are fine.

Brands hobbyists actually use

PAR-by-PAR ranked. Pick by tank footprint and the coral mix you'll keep.

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Last reviewed