Your betta fish most likely will come from a water environment somewhat different to what you have waiting at home for it, so you see it is extremely crucial to gently ease him through the transition period without actually shocking him. If you follow these steps below closely you will avoid any discomfort and harm coming to your betta fish on his initial introduction to his new home:
Keep your betta away from direct hot sunlight (as well as cold air ducts and vehicle vents) on your way back from the pet shop. Take him directly home without delay, and don’t leave him sit in your automobile for longer than it’s absolutely necessary.
Water Temperature Changes Gradually
You should float the bag or small container that your betta fish was put in the pet shop inside your aquarium and/or small fishbowl that you already have set up for him.
This will allow him to acclimatize much quicker and allow the water temperature change gradually. You should allow it to float for several minutes before you release your betta fish.
Carefullly slice open the shop bag and add a small amount of aquarium water to the bag. You should still keep the bag floating for a while in the aquarium say for about twenty minutes or so. A good idea is to use a clip or household clothespin to secure the bag to one side in order to prevent it from sinking. You should keep adding a little more of aquarium water to the bag so that your betta acclimatizes without shock.
Try and repeat this step enough times till the bag is filled with aquarium water. This method depends on the differences in the actual pH level between your aquarium water and the water used by the pet shop. This is a step that should be taken slow and take you several minutes to perform. After you complete this step you can release your fully acclimatized betta pet into his new environment.