Marine Invertebrate Acclimation Procedure

This is recommended for all crabs, shrimp, tube worms, snails, lobsters, etc.

  • Prepare your invert holding system for acclimation.
  • Float the bags containing your new animals in your invert system. If you are floating a few bags make sure that you drain some water from the system to prevent overflowing when the bags are introduced. You can keep the drained water in a bucket/s so that it can be used to refill the system once the acclimation is complete. 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 system temperature
  • Cut the bags open below the metal clips. Do not allow the water inside the bag to escape into your system.
  • Place the inverts in acclimation tubs together with their shipping water. Make sure the water level in the tubs is at about ¼ full.
  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.


  • If using tubs, start a SLOW drip of your invert holding system water. SLOWER IS BETTER!
  1. If using the shipping bags add about 1 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 again.
  1. For bags, repeat step #6.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.
  1. 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 remove the inverts from the bags/tubs making sure not to let the bag/tub water escape into your system and place the animals into your holding system. You may need to empty some of the bag water before you reach into the bags to remove the animals or you can “pour” the animals into a net held over your waste bucket/drain. Be extremely careful when handling certain inverts as many can have toxic stings or bites.
  • Discard the shipping bags and any water left in them or in the tubs.
  • Replenish the water you removed from your system during the acclimation process.

Keep the lights off/dimmed for at least the first 12 hours after acclimation.