Nano reefs (10–30 gallons) deliver a stunning visual impact in a small footprint, but the limited water volume punishes mistakes faster than larger systems. This guide details a proven 20-gallon build path that minimizes risk while maximizing color and movement.
Recommended equipment
- 20-gallon AIO (all-in-one) cube with rear chamber
- Reef-grade nano LED (50–80W full spectrum)
- Single nano powerhead, 800–1200 GPH
- 50W heater with controller
- Auto top-off (essential at this volume)
Stocking plan
A well-stocked nano holds 2–3 fish max: a clownfish pair plus one peaceful goby works beautifully. Add a small clean-up crew of 5 hermit crabs and 5 nassarius snails. For corals, lean into zoanthids, palys, mushrooms, and a few hardy LPS like duncans.Plan your full build with the Reef Equipment Planner.