Indian Almond Leaves – 5 Great Reasons To Use Them

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Indian almond leaves are a popular aquarium plant used by fish keepers for many reasons. Some of the benefits of using these leaves in an aquarium include reducing stress, boosting the immune system, and helping to create a healthy environment for your fish. Today’s article will talk about what these leaves are and their benefits. Let’s dive in!

What Are Indian Almond Leaves?

Indian Almond Leaves Outside

Indian almond leaves are leaves from the Terminalia catappa tree, also known as the Indian almond tree, which is native to parts of Asia, Africa, and Australia. These Indian almond leaves, also known as catappa leaves, are collected, dried, and sold as they are very beneficial to a variety of freshwater life and are essential for replicating blackwater ecosystems in the home aquarium.

Blackwater ecosystems are defined by their tea-colored, murky waters. Underneath these dark surfaces, the chemical and medicinal properties of the water help sustain a plethora of tropical fish and invertebrates, including wild relatives of the famous betta fish (Betta splendens).

This natural environment gets its color from decaying organics that leak tannins and tannic acid. In the aquarium, tannins can be released in the same way, especially by Indian almond leaves.

What Do Indian Almond Leaves Do In The Aquarium?

Not only do Indian almond leaves help replicate the natural ecosystems of many tropical fish, but there is a large list of benefits that come with using them in the aquarium.

Some of these benefits include:

  • Antifungal and antibacterial properties
  • Lower pH levels and soften water
  • Comfort shy and stressed fish
  • Quarantine system

Some of the only drawbacks to using Indian almond leaves are the blackwater appearance they give in the aquarium and their acidic properties. However, both can be controlled through water changes.

1. Antifungal And Antibacterial Properties

Tannins are naturally found in many trees and plants as a form of protection. They are mainly stored in the bark and new leaves where they act to defend the plant from infectious bacteria and fungi that try to enter.

In the fish tank setting, tannins act in the same way by decreasing the number of pathogens in the water column while bolstering the immune system of the fish. So much so that Indian almond leaves have been seen as a great natural addition to aquariums struggling with fin rot. Fin rot can be caused by bacteria or fungus and Indian almond leaves have been a great natural remedy.

While Indian almond leaves won’t entirely cure fin rot without any extra maintenance, they definitely increase the chances of a full recovery.

2. Lower pH Levels And Soften Water

Many tropical fish have adapted to the standard parameters of aquarium water no matter where they once originated from: 7.0 pH and 4-8 dKH. While most fish can live in these pristine conditions indefinitely, wild-caught and sensitive species will thrive in soft and acidic conditions that replicate their natural origins.

As the Indian almond leaves break down in the aquarium, they will start to release tannins and tannic acid that lower pH and general hardness. This is a gradual breakdown, and there’s little to no fear that water parameters will change too quickly for your fish to handle.

Still, it is best to test parameters regularly to make sure that your fish don’t get stressed out.

3. How Much Do They Lower pH?

The more Indian almond leaves that you add to your aquarium, the more your pH will drop due to the tannic acid being released. However, how much your pH will drop depends on some external factors that will be unique to every individual tank.

One of these factors is the carbonate hardness (KH) of the water being used. KH is the parameter that dictates how much or how little pH can be buffered at any given time. An improper KH will make changing pH levels difficult and volatile. Though this won’t make a big difference when using just a leaf or two, it’s definitely something to track with long-term use.

Other factors include the rate of decomposition, water change schedule, and use of activated carbon.

In general, it can be expected for pH levels to drop 1-2 ppm with the use of Indian almond leaves. This will usually result in pH levels settling between 5.0-7.0, which is perfect for blackwater fish species.

It is very important to keep track of pH levels when using Indian almond leaves. pH is measured on a logarithmic scale, which means that small changes in value can have much greater effects than anticipated.

4. Comfort Shy And Stressed Fish

A bed of Indian almond leaf litter can be the home of and food for many tank inhabitants. Small fish will love to take shelter in and feed on a leaf litter substrate, potentially spawning and raising nearly hatched fry. Shrimp especially love being able to forage on the undersides of the leaves and will feel comfortable reproducing in the coverage they provide.

In addition, many fish and invertebrates will appreciate dimmed lighting conditions, which can be achieved through the dark brown color of the water. If you’re struggling with particularly shyer fish or invertebrates, try adding some Indian almond leaves!

5. Quarantine System

As mentioned before, Indian almond leaves won’t be the only thing that cures your fish of fin rot or another fungal or bacterial infection, but they can definitely help speed up recovery and prepare fish for transfer to a new aquarium.

Indian almond leaves can safely be added to the quarantine or hospital fish tank system to bolster immunity, prevent some low grade infections, and improve water quality. Some fish keepers have abandoned all other forms of conventional aquarium medicines for the natural alternative of Indian almond leaves or another source of tannins.

Along with Indian almond leaves, water changes will still need to be kept up with to continue to maintain water parameters. Activated carbon may also need to be run for better control of parameters.

However, Indian almond leaves can be a simple yet effective addition to the quarantine system for extra protection against bacterial and fungal infections.

Can You Use Too Many?

Indian almond leaves can be a great addition to most fish tanks for their medicinal properties and the comfort they bring to fish.

Some hobbyists may choose to only use a few leaves here and there for aesthetic purposes while others would rather create a full leaf litter substrate that is a few inches deep. There are many ways to use Indian almond leaves, but it’s very difficult to actually use too many.

The main side effect of using too many Indian almond leaves is having very dark brown water. At some point, it will become difficult to view fish and submersed plants might even have difficulty getting the light that they need to photosynthesize.

Overly dark water can easily be fixed through a series of partial water changes or by adding activated carbon to the aquarium. Gradually the dark water will lighten in color and pH levels and water hardness will also return to where they originally were.

This is where things can become slightly problematic, though. Indian almond leaves lower pH and the hardness of the water. The more Indian almond leaves that are used, the more that those levels will decrease in the fish tank.

It is very difficult to overdose Indian almond leaves in that aspect, and usually, you will lose sight of your fish before the water becomes too acidic for them to handle. Also, remember that most of the fish found in these black waters have been known to survive in acidic water conditions down to 3.0 ppm or less.

While these levels can be deadly if changed too fast, Indian almond leaves make this change in water quality slow and steady for your fish to safely adapt.

How To Use

Indian almond leaves are inexpensive and can be found at your local pet or fish store. It is recommended to use one medium-sized leaf for every 10 gallons of water. Two may be used for the same amount of water for a stronger effect.

Indian almond leaves take only a few days to sink to the bottom of the tank. After that, they will start to noticeably decompose over the course of a month or two. There is no need to remove the Indian almond leaves at any point and they can be left to decompose until there’s nothing left. Once your Indian almond leaves are nearly all gone, add a few new ones and start the process over.

Want all the benefits of Indian almond leaves but don’t necessarily want the mess? Here is how to make Indian almond leaf extract.

How To Make Indian Almond Leaf Extract

Indian almond leaf extract is exactly what it sounds like: a concentrated dose of tannins and tannic acid excreted from Indian almond leaves. Instead of adding Indian almond leaves directly to the aquarium, an extract is a great way to get all the benefits and natural look without any of the mess.

Here are the steps to making your own extract from Indian almond leaves (you can also see the video above by AquatikGuru):

  1. Prepare dried botanicals, including Indian almond leaves, walnut leaves, and common beech leaves as well as birch and alder cones; Indian almond leaves are the most common type of leaf to use in the aquarium setting as it has been the most researched. Make sure to purchase other dried botanicals from a trusted pet store.
  2. Place a handful of these botanicals into a heat-safe container that can be sealed.
  3. Pour boiling or hot water over the Indian almond leaves and seal the container for at least 24 hours. The water will turn dark brown.
  4. At this point, the leaves may be strained out of the dark water. The Indian almond leaves may be placed directly into the aquarium for use or boiled again for another batch of Indian almond leaf extract; the only downside to reusing leaves is that they will start to decompose very quickly, which can make for a cloudy dose.
  5. The recommended Indian almond leaf extract dosage is one ounce for every one gallon of water. More than this may be added at any given time as long as pH levels are carefully tracked.

If you don’t feel like making your own extract from Indian almond leaves, then there are many products available for sale in-store and online. Some options include premade tannin concentrates or powders. However, there are a few problems with these.

The main problem with using Indian almond leaf powder is that you can’t be sure of the ingredients. Unfortunately, it is possible that the powders are treated with dyes to enhance their appearance or that they include other unknown ingredients. While these dyes and ingredients aren’t likely to hurt fish if they’re from a reputable seller, dyed powder won’t give the full benefits that Indian almond leaves could otherwise.

If you don’t want to make your own extract from Indian almond leaves, then a premade liquid concentrate would be the best option for receiving the full benefits at a reasonable cost. Many fish keepers find that liquid Indian almond leaf products don’t contain a lot of product though and can be expensive for the amount you’re getting; many extracts come in small bottles only meant to treat a small fish tank one time.

To find the best liquid Indian almond leaf extract, make sure that you’re getting a product that treats hundreds or thousands of gallons of water while remaining under a $25 budget. Otherwise, it is much more worth it to make your extract from separately purchased Indian almond leaves.

Are They Good For All Fish?

No, Indian almond leaves are not good for all fish. While many of the beloved fish, like tetras and angelfish, available in pet stores come from tropical blackwater ecosystems throughout the world, many other fish come from areas with basic, hard water instead. This includes:

Most of the fish on this list prefer neutral or heightened pH as opposed to acidic conditions. Though these fish might adapt to lower pH levels over time, subjecting them to unideal conditions for extended periods of time can potentially shorten their lifespan.

Instead, one of the best fish to use Indian almond leaves with is the betta fish, particularly wild bettas. Otherwise, Indian almond leaves are a very popular addition to freshwater shrimp tanks as dwarf shrimp love to forage in and around the leaf litter.

Wild Bettas

Most fish keepers have had a betta fish tank at one point or another in their aquarium careers. However, not many have taken the time to understand their true natural habitat preferences and how important blackwater conditions are to their success.

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Wild betta fish species originate from southeast Asia, through parts of Vietnam, Cambodia, Thailand, and Laos. There, they live in extremely shallow ponds and overflows that are littered with palm fronds and other organic matter from the thick forest canopy above.

These areas are very low in visibility and oxygen, leaving the betta fish to develop a labyrinth organ that allows them to rise to the surface of the acidic water for atmospheric air. These betta fish species are also less colorful in appearance compared to their more desirable tank-raised counterparts and have more basic reds, blues, and blacks.

While not all wild betta fish species have been brought into the aquarium hobby, some popular species include Betta imbellis, Betta macrostoma, Betta picta, and Betta pugnax.

Given what is known about these wild fish, Indian almond leaves greatly help the transition between their natural habitat and the aquarium setting. Wild betta fish thrive in soft and acidic conditions. They are also very shy fish and will do well under the dark brown color of the water and the addition of some floating plants.

How To Remove Them From Your Aquarium

Adding Indian almond leaves to your aquarium is simple enough and so is removing them. If it turns out that you can’t stand the appearance of blackwater that comes with Indian almond leaves, then you’re not stuck with it forever! However, it’s going to take some time and a little extra maintenance to get your aquarium back to where it was.

Though there isn’t much that can go wrong in the removal of Indian almond leaves from your aquarium, you want to take your time. pH and general hardness can cause problems when changed too quickly and it is better to be safe than sorry.

First, you want to remove the Indian almond leaves from your aquarium to stop any more tannins from entering the aquarium. If the Indian almond leaves are already in small pieces, then use an aquarium siphon. Do this by sections so that you don’t stir up too much leaf litter at once, causing ammonia to enter the water column and a potential mini-cycle to start.

At the same time, perform a 25% water change and add activated carbon to the aquarium. The water change will help introduce untinted water and the new desired water parameters while the activated carbon will strip the remaining tannins from the water.

Within a few weeks, your tank should be back to being crystal clear with higher pH and hardness levels.

Other Alternatives

As mentioned before, Indian almond leaves are the most popular aquarium botanical as effects have been studied for years. Hobbyists have tried many other options though, including using leaves and cones that they might find on their own properties.

Some popular alternatives include:

  • Peat moss
  • Driftwood
  • Walnut leaves
  • Common beech leaves
  • Birch and alder cones
  • Oak leaves

Driftwood is not commonly seen as a way to introduce tannins, but tannins are the reason your aquarium turns brown after adding new pieces of driftwood! Driftwood is a great alternative to botanicals altogether, especially if going for a minimal aesthetic with rocks and wood features.

If planning to collect your own botanicals, like oak leaves, survey the area for possible sources of contamination. This mainly results from runoff and pesticides but can also be from animal defecation. If there are any signs of contamination at all, do not add them to your aquarium.

Also, make sure that the leaves are completely dried as live ones can release unwanted toxins into the aquarium.

Where to Buy

Indian almond leaves can be purchased at specialty fish stores or online. If you are looking to purchase them online, check out the links below. Both sellers offer high-quality leaves at great prices.

Final Thoughts

Indian almond leaves have antibacterial and antifungal properties which can help prevent and cure low-grade infections, like fin rot, while lowering pH and water hardness. They can help shy fish feel safer and become the home to an assortment of fry and juvenile fish and invertebrates.

The only problem with using Indian almond leaves is that they can create an undesired dark tint to the aquarium water, which not all hobbyists will find appealing. These effects will need to be reversed through a series of partial water changes and the use of activated carbon.

In most cases though, the benefits outweigh the cons, especially if keeping a blackwater fish species!


  1. Hello Mark,
    I’m a beginner to the world of catappa leaves lol. I’ve owned my lovely betta, Kobe, for 7 months.

    My 5-gallon aquarium uses a charcoal/carbon-activated filter media which I replace on a monthly basis.

    If I understand correctly, my media should NOT be used with catappa leaves because the carbon will negate the benefits of the leaves?

    What filter media should I be using if I wish to continue placing catappa leaves in Kobe’s aquarium?

    Thank you.
    Linda & Kobe


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