Setting up your first reef aquarium in 8 steps

A marine aquarium with corals and reef fish is one of the most beautiful things you can have at home. The most important ingredient is patience: rushing is the main cause of failed starts.

1. Choose a tank that is not too small

A larger volume of water is more stable. For beginners, 100 to 300 litres is a good start.

2. Use reverse osmosis water

Tap water contains phosphate, nitrate and silicate that cause algae outbreaks. Make your water with a reverse osmosis unit.

3. Mix the salt to the right strength

Aim for a salinity of 35 ppt (a specific gravity of about 1.025–1.026). Measure with a refractometer; it is much more accurate than a floating hydrometer.

4. Rock and substrate

Build an open rockscape with room for water flow. Dry rock is free of pests, but needs a bacterial starter to get going.

5. Let the tank cycle

The nitrogen cycle (ammonia → nitrite → nitrate) usually takes 4 to 6 weeks. Test regularly and only add livestock once ammonia and nitrite are at zero.

6. Equipment

• Protein skimmer: removes waste before it breaks down
• Wavemakers: corals need water movement
• Heater: keep the temperature between 24 and 26 °C
• LED lighting: suitable for corals

7. The first inhabitants

Start with a clean-up crew of snails and hermit crabs. Hardy fish such as the clownfish come next. Preferably choose captive-bred specimens; they are used to aquarium life. An anemone is not required, by the way: clownfish do just fine without one.

8. Keep parameters stable

• KH: 7–9 dKH
• Calcium: 400–450 mg/l
• Magnesium: 1250–1350 mg/l
• Change about 10 percent of the water every week