How to acclimate corals that arrive in the post (UK guide)

A coral that has been in a bag for a day is stressed, not damaged. How you unpack and settle it matters more than any product you add to the tank. This is the routine we would follow for a frag arriving from us.

1. Open the parcel in a dim room

Bright light on a stressed coral makes things worse. Dim the room, take the corals out of the box and check each bag or cup. If anything looks wrong, take a photo of the coral in its unopened bag or cup and contact us within 2 hours of delivery. Our refund policy explains the process.

2. Match the temperature

Float the sealed bag or cup in your tank for 15 to 20 minutes so the temperature evens out. If it arrived with a heat pack, the water may be warmer than your tank, so the float matters.

3. Do not tip the shipping water into your tank

The water in the bag has been through a day of waste and low oxygen. Lift the coral out and leave the water behind.

4. Dip if you dip

If you use a coral dip, follow the product label and keep it short. Quarantine is ideal when you have the space, especially for corals going into a tank with expensive stock.

5. Start low and shaded

Place the frag low in the tank, out of the strongest light and flow, for the first week. Then raise it a little at a time over one to two weeks. As a rough guide, zoanthids usually sit in about 75 to 150 PAR and mushroom corals in about 30 to 100. Our PAR guide lists typical ranges.

6. Give it time

Polyps can stay closed for a day or two. Do not keep moving the coral. Watch for tissue loss, a shrinking mat or a bad smell rather than for closed polyps alone.

Handling zoanthids

Zoanthids can contain palytoxin. Wear gloves and eye protection, never touch your face while handling them, and do not scrape or boil them in a closed room.

Browse zoanthids or mushroom corals, or see everything on the shop.