Your first reef corals

Your first corals should be ones that survive mistakes: a salinity swing, a light that's too strong, a missed water change. Plenty of beautiful corals do. The expensive, demanding ones can wait until the tank has proved itself.

The forgiving ones

• Mushrooms and Rhodactis: low light, low flow, almost unkillable.
• Zoanthids: colourful, spread steadily, and tolerate a wide range of light.
• Kenya tree and leather corals: tough soft corals that grow quickly.
• Green star polyps: nearly impossible to kill, which is exactly why you keep them on their own rock.
• Duncan and candy cane corals: the easiest large-polyp stony corals.

When to add them

Wait until the tank is two to three months old, the diatom bloom has passed, and your salinity and temperature have been steady for a few weeks. Corals are more sensitive to swings than fish.

Adding a coral step by step

1. Float the bag to match temperature, about 15 minutes.
2. Dip it in a coral dip in a separate container, following the dip's directions, to knock off pests.
3. Place it low in the tank at first, even if it will eventually live higher up.
4. Move it up the rockwork over a week or two as it opens well. Sudden bright light bleaches corals.
5. Glue or wedge it in place so snails and fish can't knock it over.

Placement and space

• Low light, low flow corals go on the sand or low rock; stony corals go higher, nearer the light.
• Leave space between colonies. Many corals sting their neighbours, and the builder warns you when a stinger is in the tank.
• Keep fast spreaders on isolated rock so they can't smother slower corals.

When to move up

Once soft corals have grown for a few months and your alkalinity stays steady week to week, you're ready for more LPS corals. Leave SPS like Acropora until the tank is at least six months old and your testing routine is second nature.

General hobby guidance, not veterinary or engineering advice. Sources disagree on specifics, so watch your own tank.