When purchasing fish from the fish shop, several steps should be taken in order to ensure fish's health. These steps are essential to ensure that the fish introduced would not suffer from fish stress.
Water parameters tested is the pH, chlorine levels as well as the water temperature. The pH level of the water should be close to that of the fish shop's water. Chlorine should be zero and the water temperature should be at an appropriate level of the fish species.
Turning the light off during introduction would reduce stress. Upon arrival at home, place the plastic in the tank, letting it float unopened for fifteen to twenty minutes. While waiting, you may want to rearrange decorative figures in the tank. By making movements to the decorative figures, it will help to break up the territories of fish that you already have. This will result in less fighting while the new fish try to find their place in the tank. After the fifteen or twenty minutes are up and the water temperature is stabilised with the tank's, acclimatising the fish is the next step.
Importantly, you should not mix the water from the store into your tank. Carefully open the bag and using a cup, scoop an equal amount of water from the tank into the bag for a 1:1 ratio. Once it is done, close the bag and allow it to float for another fifteen to twenty minutes. For sensitive fishes, report this step five or six times.
Lastly, place a net into the bag and lift the fish out. Transfer the fish quickly and gently transferring it to the tank. Discard the water from the plastic bag in the sink and never mix it into the tank. Leave the light off for several hours to allow the fish to adjust to the new setting.