Almond leaves on a tree.
Almond leaves, also called Indian Almond Leaves (IAL), are used in home aquariums as a water conditioner. Their benefit has not yet been scientifically proven, but many fish breeders claim that they are good for their fish. Almond leaves are said to be beneficial to the betta, also known as the Siamese fighting fish, by adding substances called tannins to the water. Anecdotal evidence suggests that these tannins improve the habitat by making it more brackish, which the betta likes and mimics the waters of its home in Southeast Asia. Almond leaves also speed healing, promote general health, and promote ideal spawning conditions.
Tannins can be introduced into an aquarium by driftwood, and many aquarists who prefer not to change the acidity level of the aquarium soak driftwood before placing it in their tanks.
The tannins in the almond leaves will alter the acid level in the tank, bringing it down to a range that bettas prefer and thrive on. This natural substance can block fungal growth and strengthen the betta’s immune system. Tannins can also be introduced into an aquarium by driftwood, and many aquarists who prefer not to change the acidity level in their tanks will soak the wood before placing it in their tanks to remove much of the tannin.
In Asia, bettas prepare for their wrestling displays by exposing them to almond leaves. This exposure is believed to prevent serious injury by hardening and smoothing the fish’s scales, which prevents another betta from biting hard enough to cause more serious injury. The fish are pre-treated with almond leaves for a week and then treated again after the fight to promote post-battle healing.
Almond leaves are also commonly known as cepang leaves and catappa leaves. Other types of fish that have been shown to benefit from inclusion in the aquarium include catfish, rasboras, tetras, discus, and dwarf cichlids. Additional benefits include promoting more vibrant fish colors and healthier fins, as well as discouraging parasites.