In Aquariums, How Do I Use Almond Leaves?

Almond leaves, also called Indian almond leaves (IAL), are used in home aquariums as a water conditioner. Their benefit remains unproven scientifically, but many fish keepers claim they are good from their fish. Almond leaves are said to be beneficial for 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 is to a betta’s liking and mimics its Southeast Asian home waters. Almond leaves also are said to speed healing, encourage better health overall and promote optimum spawning conditions.

The tannins from almond leaves will change the acidic level in the tank, lowering it to a range that bettas prefer and thrive in. This natural substance can block fungus growth and strengthen a betta’s immune system. Tannins can also be introduced into an aquarium by driftwood, and many aquarists who prefer not to change the level of acidity in their tanks will soak the driftwood before placing it in their tanks to remove much of the tannins.

In Asia, bettas are prepped for their fighting displays by exposure to almond leaves. It is believed this exposure prevents serious injury by hardening and smoothing the fish’s scales, preventing another betta from biting hard enough to inflict more serious wounds. The fish are pre-treated with almond leaves for a week, and then treated again after the fight to promote healing after the battle.

Almond leaves are also commonly known as ketapang leaves and catappa leaves. Other types of fish that have been shown to benefit from their inclusion in the fish tank are catfish, rasbora, tetras, discus and dwarf cichlids. Additional benefits include the promotion of more vibrant colors in the fish and healthier fins, plus the discouragement of parasites.

Almond leaves release tannins into the water, which have antifungal and antibacterial properties, beneficial for fish health. They create a natural environment, similar to the habitats of many tropical fish, and can lower pH levels slightly, which is preferred by certain species. Additionally, they serve as a food source for beneficial microfauna and a hiding place for shy or breeding fish.

The general recommendation is to use one large leaf per 10 gallons of water. However, this can vary depending on the size of the leaves and the desired effect. Start with fewer leaves and observe your water parameters and fish behavior, adjusting as necessary. It's important to monitor the pH and tannin levels to avoid drastic changes in water chemistry.

Before adding almond leaves to your aquarium, rinse them thoroughly in clean water to remove any debris or contaminants. Some aquarists also choose to boil the leaves for 10-15 minutes to sterilize them and release tannins more quickly. After boiling, let the leaves cool before placing them in the tank, or simply add them directly to the water if you prefer a gradual release of tannins.

Almond leaves typically decompose over a period of 2-4 weeks, depending on the leaf size and water conditions. Once they start to break down and lose their color, it's time to replace them. Some aquarists leave the decomposed leaves in the tank to serve as detritus for microorganisms, while others prefer to remove them to maintain a cleaner appearance.

Yes, almond leaves can alter water parameters by releasing tannins that may slightly lower the pH and hardness of the water. This is generally beneficial for species that thrive in soft, acidic environments. It's essential to monitor water parameters regularly with a test kit to ensure they remain within a safe range for your fish.

Almond leaves are most suitable for freshwater tropical aquariums, particularly those housing species from blackwater habitats, like bettas, tetras, and dwarf cichlids. They are not recommended for marine or reef aquariums, or freshwater tanks with species that prefer hard, alkaline water, as the tannins released can conflict with the needs of these organisms.