Marine Fish Acclimation Procedure

  • Prepare your fish quarantine/fish holding system for acclimation. If using a fish quarantine system (HIGHLY recommended), the water chemistry and parameters in the quarantine system should match your holding system as closely as possible. Make sure that the water volume in the system you are using is low enough that it won’t overflow once bags are floated in the tanks.
  • Turn off or dim the lights in the room. Red lights can be used to illuminate.
  • Equalize the temperature in the shipping bags with your quarantine/holding system by floating the bags in the water. DO NOT CUT THE BAGS OPEN YET. Float the bags for at least 10-15 minutes. If your bags feel excessively warm or cold when you receive them, float them for up to 30 minutes or until the bag temperatures measure close to your tank temperature.
  • Cut the bags open below the metal clips. Do not allow the water inside the bags to escape into your system.
  • If using acclimation buckets/tubs, pour the fish in their shipping water into the tubs. If you have mutually aggressive species (angels, basslets, etc), make sure that you have a way to keep them separated. Pour out excess water so that the tub is about ¼ full (the water is just over the top of the fish).
  1. If using the plastic shipping bags (not recommended), leave them floating in the water making sure that the shipping water does not mix with the system water.
  • VERY IMPORTANT – add an ammonia reducing agent like Amquel or Chloramx to either the tubs or into each bag. Ammonia is relatively non-toxic in its ionic form (ammonium) at lower pH. As soon as the pH rises the ammonia changes to toxic ammonia. For this reason it is 100% essential to get rid of as much ammonia as possible prior to any further acclimation steps. FAILURE TO EXERCISE THIS IMPORTANT STEP CAN CAUSE SEVERE AND IRREVERSIBLE DAMAGE TO YOUR MARINE ANIMALS, VERY OFTEN RESULTING IN IMMEDIATE OR DELAYED DEATH. PLEASE CHECK THE AMMONIA REDUCING PRODUCT YOU SELECT FOR SAFETY WITH INVERTEBRATES AND CORALS BEFORE USING IT ON THOSE ANIMALS.
  • Add a gentle supply of air to each tub via an airstone.
  • If using tubs, start a SLOW drip of your fish quarantine/fish holding system water. SLOWER IS BETTER!
  1. If using the shipping bags add about a cup of system water to each bag.
  • As soon as the tubs are almost full, pour out the water to waste so that the tubs are 1/2 full.
  1. For bags, repeat step #7.b. every 5 minutes until the bags are full. Do not allow the water inside the bags to escape into your system. When the bags are full, empty half the contents of each bag to waste.
  • Allow the tubs to fill again with drip water.
  • Add about 1 cup of your system water to each bag every five minutes until the bags are full again.
  • At this point the pH, specific gravity, and temperature in the tubs/bags should match that of your system. The ammonia should also be minimal or zero.
  • Carefully net the fish inside the tubs and dip them in a tub/bucket containing a prepared commercial fish dip. Choose a dip that has broad spectrum medicating properties and, preferably a stress coat. Follow the manufacturer’s directions on the dip bottle carefully – do not expose your fish to the dip for longer than is advised as some dips can be dangerous to fish health after long exposure. NEVER USE ANY FISH DIP ON INVERTEBRATES OR CORALS UNLESS IT IS SPECIFICALLY RECOMMENDED FOR THAT USE BY THE MANUFACTURER.
  1. Carefully net the fish from the bags and dip in the same way.
  • Remove the fish from the dip tub into your fish quarantine system. If you do not have access to a quarantine system (HIGHLY recommended) place the fish into your fish holding system.
  • Discard the shipping bags and any water left in them or in the acclimation tubs.
  • Keep the lights in the room off/dimmed for at least the first 12 hours after acclimation. Again, red light can be used.
  • Replenish any water you removed from your acclimation/holding system before you floated the bags.