Whether you have livestock shipped directly to your door or purchase your pets from the local fish store, it is important that any new life you intend to put into your aquarium be properly acclimated first.

Proper acclimation actually helps reduce the stress animals face after relocation. In fact, the acclimation procedure itself is fairly simple although it does vary slightly for different species of animals. Sensitive fish, corals and invertebrates, such as snails, crabs and shrimp take longer to acclimate than hardier fish, corals and inverts.

In this article, we will cover some of the ways to properly acclimate animals to an aquarium and provide you with some tips and product recommendations along the way.

Checklist of Items Needed for Proper Acclimation

The following three parameters play such significant role in the well-being of new livestock that we'll go over them, one-by-one, to explain why each is important and how it impacts the health of your animal(s).


It is also likely the water inside the bag/package your new livestock arrived in has a different salinity than the water inside your aquarium. Beware: sudden changes in salinity can shock fish and inverts and may leave them more susceptible to infection and/or disease. We recommend a salinity of 1.019-1.023 for fish-only (FO) systems and a slightly higher salinity—1.024-1.026—for reef aquariums.

pH and Ammonia

refractometerThe natural metabolic processes of fish and corals releases toxic ammonia and carbon dioxide during shipping, lowering the pH of the water. At lower ranges, harmful ammonia is transformed into an inter-form ammonium. If the pH were suddenly raised, the ammonium would release ammonia harmful to animals. Proper acclimation will raise the pH slowly, safely releasing and removing ammonia. Keep in mind too that while this occurs more frequently during shipment of livestock, it also occurs while transporting new animals home from your local fish store, albeit not as extreme.

Fish should be quarantined for a minimum of 14 days before introducing them into a display tank. Quarantining inverts and corals is also advised to avoid introducing pests and disease into your display tank (be on the lookout this fall for a companion article on pests and diseases). Inverts and corals should be quarantined separately from fish so you can easily observe specimens and inspect for parasites.

If you're looking for specific information about quarantine tanks/systems, like what to do in the event of a problem, I encourage you to visit the Team Marine Depot section of the Marine Depot Forums and read Quarantine Methodology in the Marine Depot Education Center.