Acclimating Fish & Corals - Aquarium Guide How To

toadstool coral


We recently launched our new Acclimate Kits which provide all the tools you need when adding a new addition to your aquarium

they can be found here

acclimation kits reef tank


Below are full step by step instructions for acclimatising fish and corals:






**Note most corals will shrink / shrivel up considerably during transit and will re-open once settled – this can sometimes take several days**

The decision to properly acclimate is down to you but at the very least you should usually introduce new water slowly before adding specimen into the tank, with delicate species slow drip acclimation will be necessary, less care can be taken with hardy species but its always best to err on the side of caution. An exception should be made if LIVESTOCK HAS SPENT AN EXTENDED PERIOD IN TRANSIT DUE TO DELAY OR SHIPPING WATER LOOKS / SMELLS VERY BAD – IN THESE CASES ITS BEST TO ADD DIRECTLY TO TANK and dispose of all shipping water.

new fish adding how to


The proper acclimation of a new arrival is extremely important considering the amount of stress the coral has endured before arriving at your door. We recommend that the following procedure be followed immediately upon receipt of the livestock. The entire process is actually very simple and should take less than half an hour to complete.


Basic guide:

Step 1: Turn the Aquarium Lights OFF

The livestock has been in complete darkness for the last day, and will not immediately adjust to high output aquarium lighting. By turning off the lights, you remove a possible source of stress for the new arrival. Overexposure to light in general can be an issue with new additions to your reef tank.  It only takes a day or two under high light conditions to severely damage a coral that was grown under more modest illumination.

Step 2: Empty the containers into a slightly larger tub

Typically we use a small plastic tub to acclimate the new corals. If you like, you can empty the containers with the coral into separate tubs, however when we receive new corals, we tend to place them in the same tub.The purpose of this is to provide enough volume to add in water from the aquarium as well as prepare a pest control dip solution.

Step 3: Add 1/2 cup of Aquarium Water every few minutes

The slower you add the water the better. Corals and other invertebrates are sensitive to fluctuations in pH and especially salinity.  Some aquarists prefer drip acclimating corals making this process even more gradual, but one should consider the temperature drop-off that occurs during this time as well.  The entire acclimation process should not take more than 30 minutes.


fish tank

Step 4 (optional): Pest Control Dip

We advocate using pest control dips to reduce the risk of hitchhikers and parasites making it into your aquariums.We dip our corals often, even when moving corals between systems, but there is no guarantee that the threat is eliminated. The two types of dip used most often is Coral Rx for pests such as flatworms and nudibranchs an Lugol’s Iodine for bacterial infections.

Step 5: Release the specimen into the tank

Find a suitable location where the new coral will receive the appropriate flow and lower light. It will need a few days to adjust to the new lighting.If you have access to a quarantine system, we recommend using the above method to first acclimate the new arrival. After the quarantine period is over, repeat the procedure to introduce the specimen into the display tank.



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Drip Method
This method is considered more advanced. It is geared toward sensitive inhabitants such as corals,shrimpsea stars, and wrasses. You will need airline tubing or an acclimation kit and must be willing to monitor the entire process. Gather a clean, 3 or 5-gallon bucket designated for aquarium use only. If acclimating both fish and invertebrates, use a separate bucket for each.

  1. Start with Steps 1-3 of the floating method to acclimate water temperature.

  2. Carefully empty the contents of the bags (including the water) into the buckets making sure not to expose sensitive invertebrates to the air. Depending on the amount of water in each bag, this may require tilting the bucket at a 45 degree angle to make sure the animals are fully submerged You may need a prop or wedge to help hold the bucket in this position until there is enough liquid in the bucket to put it back to a level position.

  3. Using airline tubing, set up and run a siphon drip line from the main aquarium to each bucket. You’ll need separate airline tubing for each bucket used. Tie several loose knots in the airline tubing, or use a plastic or other non-metal valves. you'll be placing into each of the buckets. When water begins flowing through the tubing, adjust the drip (by tightening one of the knots or adjusting the control valve) to a rate of about 2-4 drips per second (

  4. When the water volume in the bucket doubles, discard half and begin the drip again until the volume doubles once more – about one hour.

  5. At this point, the specimens can be transferred to the aquarium. Sponges, clams, and gorgonians should never be directly exposed to air. Gently scoop them out of the drip bucket with the specimen bag, making sure they’re fully covered in water. Submerge the bag underwater in the aquarium and gently remove the specimen from the bag. Next, seal off the bag underwater by twisting the opening, and remove it from the aquarium. Discard both the bag and the enclosed water. A tiny amount of the diluted water will escape into the aquarium; this is O.K. Also, to avoid damage, please remember never to touch the "fleshy" part of live coral when handling.

Important Facts

  • Never place an air stone into the shipping bag when acclimating your new arrival. This will increase the pH of the shipping water too quickly and expose your new arrival to lethal ammonia.

  • Keep aquarium lights off for at least four hours after the new arrival is introduced into the aquarium.

  • Sponges, clams, scallops, and gorgonians should never be directly exposed to air. Follow the acclimation procedure, but instead of netting the specimen out of the shipping bag, submerge the bag underwater in the aquarium and remove the marine life from the bag. Seal off the shipping bag underwater by twisting the opening, and remove it from the aquarium. Discard both the shipping bag and the enclosed water. A tiny amount of the diluted shipping water will escape into the aquarium. Don't be alarmed; this will have no adverse affect on the tank inhabitants.

Some live corals produce excess slime when shipped. After the acclimation procedure is followed, hold the coral by the rock or skeletal base and gently shake the coral in the shipping bag before placing into the aquarium. To avoid damage, please remember never to touch the "fleshy" part of a live coral. Many species of coral will not open for several days after introduction into their new home. Please allow several days for the coral to adapt to the new conditions in the aquarium

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