Is there a better feeling than adding something new to your reef tank? Buying new corals feels like opening presents on a holiday. We got in some new corals and while acclimating them to our tanks, it reminded me how many times my customers ask how to go about acclimating new arrivals to their own reef tanks. I’ve probably acclimated new corals a thousand times over the years, so it’s become a bit of an afterthought, but I can relate to some apprehension on the part of newer aquarists.
Like many things in the reef aquarium hobby, there are many ways to do it, but the fundamentals are fairly consistent. We want to introduce the new corals to the tank with as little shock as possible and avoid as much as possible any issues with unwanted hitchhikers. The former deals with ensuring the safety of the new additions while the latter is all about protecting the original inhabitants from the new corals.
Step 1: Float the corals to stabilize temps

Coral bags floating to equalize temperature
The time it takes to equilibrate the temperature in the bag or shipping container will depend on the amount of water and the difference in temperature. As a general rule, we like to float the new corals for at least 10-15 minutes.
Step 2: Place corals in larger container

Placing new corals into a larger container
This can get tricky with orders received online because they often do not come in a lot of water. Shipping large bags of water is incredibly expensive, so shippers will often use as little water as possible without threatening the safety of the animals.
The best thing to do in this case is to pour the water into a smaller container, like a cup, before setting it into a large basin. That way, the coral stays submerged the whole time and you can add water slowly to the cup and let it overflow into the basin.
Step 3: Slowly introduce water from your system

Dripping system water into the coral container
This approach works fine, but as a personal preference, I like to use a 5-gallon container filled with just enough water to fill the basin so if I were to forget that I started the drip, I wouldn’t empty my tank onto the floor.
Step 4: Use corals dips to prevent infestations

Coral drips help lower the risk of pest infestations in your system
The dipping procedure lasts about 10-15 minutes, and during the process, we blow off the corals with a turkey baster to dislodge potential hitchhikers that have been stunned by the solution.
Hopefully these guidelines (and the video below) are helpful to folks curious about how to acclimate new corals.
Photo & Video Credit: Tidal Gardens
What about light-acclimating?
I have done this at least a thousands times and I do all the steps 1,2 and 3 in step 4 I will just pick off anything with close inspection I see that is not wanted in the aquarium. I do not use any dips unless there is a problem with shipping. Like a late delivery and the water is extremely bad. My set up ensures that most infections are taken care of.
Hi Dave; wonderfully, & clearly written article on dipping. I’ve just ordered my dip from Amazon but what I’d like to ask you is which do you do first, dip or acclimatise your new purchase OR could the two be done in one procedure?
From what you’ve said clearly the dipping has to come first or you are possibly introducing unwelcome visitors into your tank?
thanks
Russi