Acclimating Corals to the marine reef aquarium

This Hobbyist Guide focuses on the steps a hobbyist should take to safely add a marine coral to their reef aquarium. The recommended steps are clearly laid out, so that a hobbyist of any level will benefit from this guide. Notes and warnings are included for areas that require special attention or are common areas where new hobbyists typically make mistakes.

Why we need to Acclimate Corals

The vast majority of aquarium hobbyists strive to provide the best possible environment and care for all of their aquariums inhabitants. It is because of this attention to excellent husbandry, that collectively as a hobby, reef aquarists have learned the best methods in which to introduce and maintain corals within the aquarium environment. There is probably no more critical time for a coral than during the process of being transported home and introduced into the hobbyists reef aquarium. During this period of time the coral will be subjected to many stresses, that while inevitable, can be greatly reduced through the care and technique that the marine aquarium hobbyist uses to introduce the new coral into its new home. In order to safely acclimate Corals into an already established aquarium it is important to closely follow this proven set of procedures designed to limit any stress on the new specimen and get it acclimated as quickly as possible.

It is highly recommended to look over all the steps ahead of time and be sure to have all the necesarry items handy and ready to go prior to the arrival of the new coral specimen. This acclimation procedure is a safe and easy way to introduce Corals from the relatively stressful water chemistry of its shipping bag to the healthy and safe conditions of its new home. Though it may seem like the best course of action is to get your new specimen into your clean aquarium as soon as possible, it is extremely important to note that rapid changes in water conditions or chemistry can be more dangerous to an aquatic animal than being kept longer in an unhealthy environment. It is this slow transition from shipping container to established tank that is the focus of this acclimation procedure.

Note: It is generally recommended that all newly purchased specimens be quarantined in a separate tank before introduction to the population of your established aquarium; however, the acclimation process is the same either way (assuming the quarantine tank has the same water chemistry as the main aquarium).

Acclimating corals into an established reef aquarium

Note: This procedure should not take any more than 1 hour to complete.

Important Note: Never expose sponges and gorganians (sea fans) to open air. This is the only case where you will have to introduce some of the bag water into your aquarium.

Before you start, you will need the following:

  • Non-abrasive net
  • Plastic or glass cup
  • Clean plastic or glass container to keep the specimen during the acclimation process
  • A means to access water from your aquarium
  • Aquarium Thermometer

Steps to take to properly acclimate a new Coral specimen

  • Open the bag or shipping container and carefully place coral with the water from the bag into the empty bucket or container.
  • Add 1 cup of your aquarium water to the bucket slowly.
  • Repeat this process adding 1 cup of aquarium water every 5 minutes for 30 minutes.
  • Dim or turn off the aquarium lights to help minimize stress on the new coral.
  • Carefully remove the coral or clam from the bucket. Be extremely careful when handling live corals not to touch the delicate flesh of the animals. Try to handle the corals only by their hard skeletons or the plug or coral rubble that they are attached to whenever possible.
  • Place your new coral in a location within your reef community that will not place the newly introduced specimens too close to other well established or aggressive species, as they will sting their new competitors. Check on compatibility issues to see where your new coral should be placed in its new home. Remember that many aggressive coral species extend their sweeper tentacles mainly at night, so what may seem to be a peaceful environment during daylight hours may not be once the lights go out.
  • Discard the water left in the bucket. EXCEPTION: Never expose sponges and gorganians (sea fans) to open air. This is the only case where you will have to introduce some of the bag water into your aquarium.
  • Keep the aquarium lights off or at a low level and gradually work up to a higher level, allowing the coral(s) time to adjust before returning lighting to full operating levels. This process should ideally occur over a 2 to 3 hour period.
  • At this time your coral species will be ready to coexist with its fellow tank mates.


By following these steps a reef aquarium hobbyist of any level should be able to properly acclimate a new coral specimen to their established reef aquarium. It is also recommended that the aquarium hobbyist pay close attention to their new coral specimen(s) during acclimation and in the short term afterwords to verify that the coral is doing well and taking to its new environment.

Helpful Hints:

  • When Acclimating corals, begin with a low level of lighting and gradually work up to a higher level, allowing the coral(s) time to adjust before lighting increases.
  • Never introduce an airstone or any other form of aeration into the shipping bag. Aerating the water inside the shipping bag will only convert non-toxic ammonia to a toxic form that will be extremely harmful to the animal.
  • Never expose sponges and gorganians (sea fans) to open air. This is the only case where you will have to introduce some of the bag water into your aquarium. THESE SPECIES MUST BE KEPT UNDER WATER AT ALL TIMES.
  • Do not be too anxious to admire your new specimen. Allow them to adjust to their new home before you expose them to bright lights and attention.

One Response to “Acclimating Corals to the marine reef aquarium”:

  1. Dottie Williams on 13-12-’14 21:01

    I just got my first coral. It is a Kenya tree coral. I have it in the aquiriam. Do I put the trunk in the sand or let it be?

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