Setting Up Your First Reef Tank

Bigger tanks are more stable and forgiving — water parameters swing more slowly when there's more water volume. A 90–120L (24–32 gal) tank is a good starting point: large enough to be stable, small enough to fit most spaces and budgets.

Nano tanks (under 40L) look appealing but are unforgiving. A single dead snail can crash water quality overnight. Start larger if you can.

Lighting: For a mixed reef with LPS and softies, a quality LED fixture (Aquaillumination, Radion, Kessil, or reputable Chinese alternatives like Neptune Apex T5) works well. SPS requires stronger and more consistent PAR (250–350+ at colony location).

Filtration: A sump with a protein skimmer is the gold standard. The sump adds water volume, houses equipment out of sight, and allows a refugium section. A hang-on-back skimmer works on tanks without sumps.

Flow: Corals need flow to remove waste from their tissue and deliver nutrients. Aim for 30–50× total tank volume turnover per hour from powerheads. Use wavemakers for random flow patterns.

Heating/Chilling: In Singapore's climate, a chiller is not optional for a reef tank. Size it generously — a chiller working at 30–50% capacity is more reliable than one maxed out.

Refractometer or salinity probe: Essential for measuring salt levels accurately.

Never use tap water in a reef tank. Singapore tap water contains chloramine, phosphate, silicate, and other contaminants that fuel algae and harm corals. Use RODI (reverse osmosis with deionisation) water exclusively.

Mix your salt in a clean container with a powerhead — allow at least 30 minutes of mixing before testing salinity. Aim for 1.025–1.026 SG. Good salt mixes (Red Sea, Reef Crystals, IO Reef Crystals) already contain the correct Ca/Mg/Alk ratios for a reef.

See the Nitrogen Cycle guide for full details. For a reef tank, the most effective method is to start with cured live rock plus a bottle of live bacteria (MicroBacter7 or similar). This approach can cycle the tank in 2–3 weeks.

During cycling, keep lights on a reduced schedule (6–8 hours) to discourage algae before the tank is stable. Test ammonia and nitrite every 2–3 days. The tank is ready for livestock when both read zero for 48 hours straight.

Almost every new tank goes through an ugly phase after cycling: a brown diatom bloom coats every surface, followed by green hair algae, then possibly cyanobacteria (red slime). This is completely normal and usually self-resolving within 2–4 months.

Diatoms are fed by silicates leaching from new substrate. They disappear once the silicates are depleted. Herbivores like turbo snails, cerith snails, and a sea urchin will accelerate cleanup. Do not overreact — nuking the tank with chemicals sets you back significantly.

Add livestock slowly. Start with hardy, reef-safe fish — a pair of ocellaris clownfish are the classic first fish for a reason. Wait 4–6 weeks before adding the next fish, and never exceed 1 cm of fish per 10L of tank volume.

For corals, start with easy softies (mushrooms, zoanthids, toadstool leather) and LPS (hammer, frogspawn, torch). These tolerate parameter swings better than SPS. Graduate to SPS only when your parameters are stable for months.

Always quarantine new fish in a separate 40L+ QT tank for 4 weeks before introducing to the display. Ich and velvet are nearly impossible to eradicate from an established tank once introduced.