Are Indian Almond Leaves Good for Aquarium Fish?
Have you ever seen a stack of large, dried leaves at the fish store and wondered what they are for? Terminalia Catappa (IAL) is a tree that comes from India and Oceania. It also produces catappa or Indian almond leaves. Its fruit seeds taste similar to almonds, and its leaves are commonly used in herbal teas and traditional medicines.
The Indian almond tree bears fruit and leaves
A dried catappa leaf can slowly decompose in aquarium water and create tannins. These plant-based substances gradually lower the pH level and give the water a yellow-brown hue. People don’t like the brownish tint that tannins naturally produce from leaves and driftwood. They can use chemical filtering to remove them.
What is the purpose of Catappa Leaves?
If you have sensitive species (like crystal shrimp and certain South American fish) that prefer
Low pH and low water quality
Indian almond leaves slow down the release of tannic acid and humic acid. They take longer to work than pH buffer chemicals, but their gradual effect is sometimes considered “safer” because they are less likely to cause deadly pH swings. Because of their impact on water chemistry, the leaves are generally not used for high pH fish like African cichlids and many livebearers.
While some soft water fish don’t require low pH for their normal living conditions, you may be more successful with breeding and raising their fry if you make the water more acidic. That is why breeders often use catappa leaves with their Apistogramma cichilds and betta fish (both Betta splendens and wild type bettas). For additional support, gouramis and betta fish sometimes make bubble nests under the leaves, as they float for the first few day.
Betta fish are kept in an aquarium that has tannin-tinted water
It is interesting to note that Indian almond leaves have slight antibacterial or antifungal properties. The tannins in plants help protect them from pathogens like bacteria and fungus. Scientists continue to investigate their effectiveness for human medicine. Aquarists love to use catappa plants to help their fish heal minor ailments and improve their immune systems. Tannings can be helpful for betta fish who bite their tails. For fungal growth prevention, experts suggest adding alder cones or tannin-rich leaves to hatch fish eggs.
Microorganisms consume the Indian almond leaves as they soak in water. They reproduce quickly and develop into layers of biofilm, infusoria. This microfauna can be a great food source for tiny shrimp and fry. It is often the only food that is small enough to be eaten by them in their first stages of life. You can soak several leaves in water for up to three weeks if you are going away and don’t have anyone to feed your shrimp colony. Drop them in your aquarium and they will be a great long-lasting food source for you while you are gone.
Blackwater aquarium that mimics a Brazilian forest stream
If you are looking to make a South American or blackwater aquarium that resembles the natural environment of your fish, then use lots and lots of catappa leaves. The darker water makes shiny fish like neon tetras, cardinal tetras, and certain discus really stand out. It also helps skittish fish feel more comfortable since they are more hidden from view by the tannins in the tank. The leaf litter can be used as a hiding place for fry and shy bottom dwellers, such as pygmy corydoras, if you have enough Indian almond leaves.
How to Use Indian Almond Leaves
You can wash the leaves in water if they are extremely dirty or dusty. However, the catappa leaves that Aquarium Co-Op sells are so clean, we simply drop them into the fish tank. The leaves usually stay floatin’ for 3-7 days. If you are concerned about their floating, add a rock or ornament to weigh them down. Also, you can break the leaf in half to just use part of it or crumble it into smaller pieces to speed up the decomposition process.
Ready to use in aquariums
How many catappa leaf should I use for 5-20 gallons? If you are making a blackwater tank, use more leaves and soft woods (like Malaysian driftwood and cholla wood) until you achieve the desired color.
Should I boil Indian almond leaves? We do not boil them because it releases all the tannins and then you don’t get their benefits. Some people prefer to make a catappa herb extract. This is done by boiling one of the leaves for every 0.5 gal (2 liters), of water. You should not use a pot that is too small or fragile to stain the leaves. Once the liquid has cooled you can add some to the tank until the desired color is achieved. To dilute too much extract, you can simply add more water to the tank.
When is it time to replace catappa leaves? Catappa leaves usually last between one and two months before they completely fall apart. Add another leaf to the plant to allow it to break down and release tannins.
Caridina cantonensis shrimp nibbling on the remains of a catappa leaf
If you are thinking about keeping shrimp or breeding softwater fish, or creating a blackwater biotope for your aquarium, grab some catappa leaves. Aquarium Co-Op leaves are precleaned and ready to use right out of the package.