The purpose of acclimation is simple: the water that the fish or corals are packaged in has different temperature, pH, and salinity parameters than your aquarium. Fish, and especially invertebrates (including corals), are very sensitive to even minor changes in these parameters, so proper acclimation is the key to ensuring their successful introduction into your home aquarium.
We recommend either of the two acclimation methods explained in this guide, and want to remind you the acclimation process should never be rushed. Also, remember to keep your aquarium lights off for at least four hours after your new fish, corals, or invertebrates are introduced into the aquarium to help them further adjust.
Though not a requirement of the acclimation process, it is highly recommend that all new aquatic life be quarantined in a separate aquarium for a period of at least two weeks to reduce the possibility of introducing diseases and parasites into your aquarium and to ensure they are accepting food, eating properly, and are in optimum health before their final transition to your main display.