While a betta fish grows his long, flowing fins naturally and at his own pace, you can help by promoting a healthy environment and keeping your fish stress free. Although there is no magic trick for growing large fins, doing your part offers as an owner offers benefits.
Step 1
Separate your betta from other fish. Fish such as tetras or other bettas may chew on his fins or cause damage from fighting. Put your fish in a tank that holds at least one-half gallon of water.
Step 2
Measure the pH in your betta’s tank with test strips and keep it around 7.0. Also, check the water temperature often. It should be between 72 and 82 degrees, since the betta is tropical and likes warm water -- he may become stressed in cold or hot water.
Step 3
Add 1 teaspoon of aquarium salt per 5 gallons of water. This helps remove any pathogens and kills bacteria that may damage your betta’s tail and fins.
Step 4
Feed your betta a properly balanced diet. Mosquito larvae are the betta’s natual food choice. However, live food is not a good idea since it may harbor bacteria that may invade your betta and prevent fin growth; therefore, feed him a pellet food and add freeze-dried bloodworms or brine shrimp.
