Acclimating Fish To The Aquarium

Acclimating Fish to the AquariumAcclimating fish to an aquarium is a lot easier than most people think. Below are some things to look out for when going through this process.

It is good idea to have a quarantine tank for any new fish as this gives you time to observe them for any parasites or diseases over a period of a week or more. But if you don’t it is still advisable to watch for any signs of changes when your new fish are added to your aquarium.

Feed your existing fish and turn off your aquarium lights before placing any new fish in your aquarium. Feeding will help to lessen any aggression of your older fish and the darkness will minimize stress of your new fish while they get used to their surroundings. Float the bag in the tank for about 15 to 20 minutes. This will help adjust the temperature of the bag water to the aquarium water.  If the bag is a lot cooler, let the bag sit at room temperature for about 20 to 30mins before floating it. Do not pour the bag water into the aquarium as this only adds more waste to the aquarium. Once the temperature has been matched, place a net on a bucket and gently pour the fish into the net. Add the fish to the aquarium as soon as possible.

Purchasing Online & Local Aquarium

When purchasing fish online they have usually been transported for periods of longer than 6 hours where ammonia is going to build up in the bag. The pH is going to drop over time as all of the available oxygen is used up by the fish. This will turn any Ammonia in the water into less harmful ammonium. The fish will be safer in this state than a bag full of ammonia. Once the bag is open the pH will begin to rise immediately from the increased oxygen as the water gasses off any CO2 at the surface in the bag. This will convert the ammonium back into ammonia which is extremely toxic for the fish. Remove the fish as quickly as possible from the bag and add them to the tank. The faster the better because the ammonia is rising each second the bag is open. Drip or dip acclimation is not recommended.

You can add ammonia neutralizers like Seachem’s Prime to the water which will neutralize ammonia and give you more time to place your fish into your aquarium.

Fish purchased from a local aquarium shop have usually been in the bag for less than an hour so they don’t have a lot of ammonia build up. There is not a danger of dip or drip acclimation.

Drip & Dip Acclimation

Drip acclimation is done by adding aquarium water through a small tube directly into the new bag of fish one drop at a time. Double the amount of water in the bag over a period of about 1 hour and then add the fish to the aquarium.

Dip acclimation is done by floating the bag of new fish on surface of your aquarium and adding aquarium water to the bag a cup at a time over an hour and then releasing the fish into the aquarium.


Fish are sensitive and it is best to get them into the aquarium as soon as possible so they can acclimatize to their new conditions. An hour of Drip or Dip Acclimation is not necessary and is only adding more stress to the fish as it can take up to a week for a fish to fully adjust to their new environment. The quicker the fish are placed into the aquarium so they settle the better.