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How To Properly Acclimate New Fish

Edit: Just to clarify; my HowTo is not the same as another found on another popular fish forum. Mine is different in that with mine the water in the bag is eventually completely removed. Not so with the one on the fish forum. This is not to say theirs is wrong and mine is right. Only that there are different methods for acclimation and this is mine.

The whole purpose of acclimating new fish is to slowly introduce them to the water in your quarantine tank (temperature, pH, etc.) while getting rid of the LFS water in the bag without adding it to your own aquarium. Here’s the procedure I go through with all new fish.

Have an empty bucket and a 1/2 cup measuring cup standing by.
Turn tank and room lights off.
Float the unopened bag for 15 minutes.
Open the bag and scoop out half the water in the bag and dump it in the bucket.
Scoop 1/2 cup of tank water gently into the bag.
Allow to sit for 15 minutes.
Scoop out 1/2 cup bag water and dump it into the bucket.
Scoop 1/2 cup tank water gently into the bag.
Allow to sit for 15 minutes.

Rinse and repeat the process of scooping water out of the bag and into the bucket, and scooping tank water into the bag and allowing to sit for 15 minutes for the next hour and a half or more. This gets rid of old LFS water and slowly replaces it with your tank water. When the process is over, and since all of the water in the bag is from your tank and contains no water from the LFS, you can now gently dunk the bag in the tank and release the fish without the stress of a net.

You can either do it the way I mentioned above, or purchase an inexpensive acclimation kit from Doctors Foster & Smith (I am not an affiliate. I just like their products). Either way gives you the exact same results where the old bag water is completely removed and replaced with your tank water.