How to quarantine new corals (and why it is worth the effort)

Quarantine means keeping new corals in a separate tank for a few weeks before they go into your display. The aim is simple: if something unwanted came with the coral, it stays out of the tank that holds everything you have already paid for.

What you are trying to catch

• Pests such as flatworms, nudibranchs, aiptasia and pests that eat acropora.
• Disease and tissue problems that are easier to treat in a small, empty tank.
• Weak pieces, so you do not discover them in the middle of a healthy reef.

What you need

• A small tank or tub with a heater, a powerhead and a light. It does not need to be fancy.
• Its own net, tweezers and tools. Do not share them with the display.
• Salt water at the same salinity and temperature as your display. Make this up in advance.

How long

Many keepers use two to four weeks. Pests have life cycles that run in days to weeks, so a short quarantine misses some. Longer is safer. There is no guarantee in either direction.

What to do each week

1. Look closely. Check the coral, the plug and the rock with a torch at night. Many pests come out in the dark.
2. Dip if you dip. Follow the product label and keep it short. Read our acclimation guide for the unpacking steps.
3. Do not add a lot at once. A few pieces in a small tank keep the water clean.
4. Keep notes and photos. They make changes easy to spot.

When to move it to the display

When the coral has opened fully, looks normal and you have found no pests for the whole period. Then follow the same low-light start we describe in the PAR guide.

An honest note

Quarantine lowers risk. It does not remove it, and a coral from any seller can carry something. Tell your seller if something turns up, because they will want to know.

Starting out? Read our beginner corals list, or browse the shop.