If you’re an aquarist, you’ve probably heard of Indian almond leaves (also known as Catappa leaves). These leaves of the Terminalia catappa tree are especially popular in the betta and shrimp hobby as a natural medicine and water conditioner. They are said to help combat fungus and bacterial problems like finrot, and prevent stress by mimicking the natural habitat.
As mentioned before, Indian almond leaves are the leaves of the Terminalia catappa tree, which grows in large parts of Asia. The leaves are usually harvested by simply picking them off the ground. After drying them, they are ready for use in the aquarium.
You can import Indian almond leaves directly, but nowadays they are also available in some pet-/aquarium stores and online!
When placed in an aquarium, Indian almond leaves slowly start to decompose. While this happens they turn the water a yellow or brown color by releasing tannins. These tannins gradually lower the pH and are said to have antifungal and antibacterial properties, which comes in very handy when you have a fish suffering from fin rot or when you’re raising vulnerable fry.
The dark color of the water is considered unsightly by some aquarists, but it actually mimics the natural habitat of many fish species! In fact, it’s said that a lot of fish feel less exposed when in tannin-rich water, which may help shyer fish gain more confidence. These properties and more definitely make using Indian almond leaves worth considering.
- Adding a few leaves to a quarantine tank with a sick fish can help speed up the healing process. I’ve spoken with Betta breeders who have actually stopped using regular fish medication altogether and treat sick fish with nothing but Indian almond leaves and clean water.
- When you’re dealing with fish/invertebrates that prefer soft, acidic water, Indian almond leaves can also be great for stimulating breeding. The tannins released by the leaves help create water conditions that are similar to those in the natural habitat of the fish, which means ideal breeding conditions. If you’re trying to get your Bettas or Crystal Red shrimp to breed, adding a few Indian almond leaves to the breeding tank can speed up the process!
- Indian almond leaves can also be used as beginner food for certain fish fry and baby shrimp as they feed off the decomposing matter. Not only do the leaves potentially provide a first meal but can also be used as emergency food if other food sources are scarce. Indian almond leaves also provide hides from predators.
- Indian almond leaves can actually be used to condition the water. In fact, it’s sometimes known as the “poor man’s water conditioner,” although this may be more the case for those that have ready access to natural sources. For the rest of us, getting Indian almond leaves can be expensive, so it’s typically best to buy them in bulk when possible (and you should still always use commercial water conditioner to be safe)! Since the leaves also help slowly lower the pH, it’s said to be better for keeping harmful ammonia under control since ammonia is converted to the less toxic ammonium at low pH (anything less than 8.0).
- Lastly, there are also situations where Indian almond leaves can be added to the aquarium purely because of the way they stain the water. If you’re interested in setting up an Asian blackwater biotope, which imitates blackwater rivers and streams, Indian almond leaves are a must have. They appear in these regions naturally so they are biotope correct. You can also add the leaves to other aquarium setups with fish that prefer soft, acidic water if you like the look of it.
There are a a few different ways to use Indian almond leaves; the easiest is to just place them in the aquarium and wait for them to do their job. The more you add, the darker the water gets. You can tear the leaves up if you want the tannins to release more quickly. Once they start decomposing you can take them out or replace them, but it’s also fine to wait for them to be completely decomposed. Shrimp and fry will actually appreciate it if you don’t remove the leaves because as mentioned earlier they feed on the decomposing remains.
If you’re not a big fan of leaf litter in your tanks, another option is to soak the leaves separately and adding the stained water while doing a water change. You can also make your own blackwater extract, which is a concentrated version of stained water. This is done by taking a very large amount of Indian almond leaves, boiling them in a pot of water and letting them soak for multiple days afterwards.
You only have to add a small amount of the extract to your aquarium to get that blackwater look. (And by the way, if you’re not the kind of person who stands around boiling leaves, you can also just buy your Indian almond leaf extract. We don’t judge.)
With the popularity of realistic blackwater biotope aquariums ever-growing, so is the amount of different types of dried tree bits sold by aquarium companies. Most aquarium stores nowadays not just sell the classic Indian almond leaf but might carry many other different types of litter that you can use in your tank.
Generally speaking, all of these products have the same beneficial effects as Indian almond leaves. They release beneficial tannins and help create a natural look that your fish will appreciate. So switch it up!
How about some banana-, magnolia-, oak-, mulberry- or guava leaves? Or maybe seed pods from various plants like alder cones (much appreciated by dwarf shrimp), magnolia or lotus? If that’s still not enough, you could even try twigs and bark like that from the Indian almond tree, palm fronds, or plain old oak twigs.
Some of these items you can collect yourself if a certain tree grows near you. Do keep pollution in mind, though: clean any leaf litter before using and avoid anything that’s growing in polluted areas.
If you have any more questions about Indian almond leaves and their use, leave a comment below. Happy fishkeeping!