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 are similar to almonds. The leaves of Terminalia catappa are often used in herbal teas as well as traditional medicines.

Fruit and leaves of the Indian almond tree

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?

You can request that sensitive species, such as crystal shrimp or certain South American fish, be removed.

Low pH water and low pH water

, Indian almond leaves can slowly lower pH by releasing tannic acid, humic acids, fulvic acids, and other organic compounds with weak acidity. 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.

Some soft water fish can live with low pH, but breeding and raising eggs may prove to be more rewarding if the water is made more acidic. Breeders use catappa leaves to raise betta fish (both wild and Betta splendens) and Apistogramma Cichilds. Also, since the leaves float for the first few days, betta fish and gouramis sometimes create bubble nests underneath them for additional support.

Betta Fish in an Aquarium with Tan-Tinted Water

It is interesting to note that Indian almond leaves have slight antibacterial or antifungal properties. In nature, tannins help to protect plants from attacks by bacteria, fungus, and other pathogens, and scientists continue to research their antimicrobial efficacy for possible use in human medicine. Many aquarists use catappa leaves to treat mild illnesses and boost their fish’s immune system. If your betta fish bites his tail constantly, tannins can help speed up his recovery. Some veterans also recommend adding tannin-rich leaves or alder cones when hatching fish eggs to fight off fungal growth.

As the Indian almond leaf soaks in water, microorganisms begin to consume and break it down. They quickly reproduce and form a layer of infusoria. This microfauna makes excellent food for shrimp and fry, and can even be the only food they eat in their early years. If you plan on going out of town and have no one to feed your shrimp colony, try soaking several leaves in a bucket of water for three weeks until they become very slimy with biofilm. You can then drop them into your aquarium to make a long-lasting vacation food.

Blackwater is a biotope aquarium that imitates the 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. Darker water allows shiny fish such as neon tetras and cardinal tetras to really shine. Because they are less visible from the tank’s tannins, it makes skittish fish more comfortable. If you add enough Indian almond leaves, the leaf litter can serve as hiding spots for fry or shy bottom dwellers like pygmy corydoras.

How to Use Indian Almond Leaves

If the dried leaves are very dusty or dirty, you can gently rinse them in water first, but the catappa leaves sold by Aquarium Co-Op are clean enough that we just drop them directly 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. To speed up the process of leaf decomposition, you can either cut it in half or chop it into smaller pieces.

Dried catappa leaves ready to be used in aquariums

How many catappa leaves should I use? Start with 1 leaf (approximately 4-7 inches or 10-18 cm long) for every 5-20 gallons of water. You can use more leaves or soft woods, such as cholla and Malaysian driftwood, to achieve the desired color in a blackwater tank.

Do I boil Indian almond leaves for their health benefits? Not because boiling them releases the tannins. If you don’t like how the leaves look, you can make a catappa extract by boiling one leaf per 0.5 gallons (2 liters) water. (Make sure to use a cheap pot you don’t care about because it may become stained.) Once the liquid has cooled, pour a little into the tank until you reach the color you want. You can add more extract if you need to.

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 chomping on the remains a catappa leaves

Next time you’re thinking of keeping shrimp, breeding soft water fish, or building a blackwater biotope, grab a stack of catappa leaves to get the job done. Aquarium Co-Op leaves are precleaned and ready to use right out of the package.