Setup path, stage 5

Live rock or dry rock, and sand or bare bottom

Rock is where most of the filtering bacteria live; sand is a home for burrowers and a trap for detritus. Choose with your eyes open about pests, phosphate and time.

Last checked 21 October 2026. How we check

What do you need for this stage?

• Rock (dry, or cured live rock)
• Aragonite sand, if you are using sand
• Reef-safe putty or cement if you are building a structure
• Phosphate test kit (for dry rock)
• A bucket for rinsing

Should I use live rock or dry rock?

Keepers advise soaking dry rock in RO/DI for a week and testing the water for phosphate before use (typical). BRS links tanks with near-zero nutrients to dinoflagellates, which is why very clean dry-rock tanks sometimes struggle early.

Sand bed or bare bottom?

BRS calls sand the more forgiving choice for beginners: it hosts bacteria, pods and clean-up crew, looks natural and is needed by sand-sleeping wrasses and burrowing gobies. It traps detritus if neglected and blows around in strong flow. Bare bottom makes nutrient export easy and suits high-flow SPS tanks, but it matures more slowly and cannot house sand-dependent fish. See sand bed or bare bottom for the full comparison.

A shallow bed of about 2.5 to 5 cm is the common choice. A deep sand bed is usually defined as about 10 cm or more of fine sand (typical). Red Sea notes that fresh aragonite surfaces can take up calcium and alkalinity, so expect small early drops.

How do I build the aquascape?

• Build dry, outside the tank if you can, and use putty or cement for anything that could topple.
• Stand rock on the glass, then add sand around it, so burrowing fish cannot undermine it.
• Leave space between rock and glass for flow and a cleaning magnet.
• Open structures beat walls: flow should pass through and behind the rock.
• Leave flat spots at several heights for corals that need low, medium and high light.

Rinse the sand in a bucket until the water runs nearly clear to avoid days of cloudy water.

What are the steps, in order?

1. Choose dry or live rock and sand or bare bottom.
2. For dry rock, soak a week and test the water for phosphate.
3. Build the aquascape, rock first, sand after.
4. Push each piece gently; anything that moves needs cement.
5. Fill with the salt water from stage 4 and run the pumps.
6. Look for dead spots behind the rock.

Your checklist

Tick items as you go. Ticks are saved in this browser only and fill the depth gauge.

What test must pass before moving on?

What are the common mistakes?

• Live rock straight from the shop with no look for pests.
• Stacking rock on top of sand.
• A wall of rock against the back glass with no flow behind it.
• Unrinsed sand clouding the water for days.
• Adding live rock after the cycle, which restarts it.

Where do sources disagree?

See also: Aiptasia, the pest anemone.

Figures from sources read as a search summary only are shown as typical figures: check them before you rely on them. Found a mistake? Tell us how to fix it.