Arjuna Pods | Terminalia arjuna
Arjuna Pods on the Surface:
Arjuna Pods (Terminalia arjuna) are the dried seed capsules of the Arjuna tree, a close relative of Terminalia catappa, the same family responsible for Indian Almond Leaves, one of the most widely used and studied leaf litter in the hobby. Sourced from Sri Lanka, these lightweight seed pods become encrusted with beneficial biofilms as they condition in the aquarium, mimicking the dynamic seed and leaf litter that falls from the riparian canopy into tropical streams. They release moderate tannins and humic substances as they break down into detritus, contributing to the soft, tinted water conditions that our fish would encounter in nature.
Essential Details
- Tannin Level: Moderate
- Tint Color: Warm amber to light brown
- Durability: Highly durable
- Habitat Location: Tropical climates around the globe
- Optimal For: Bettas, tetras, rasboras, dwarf cichlids, freshwater shrimp, nano fish, and all tannin-adapted species
- Use with Caution: Small pods may be a choking hazard and should not be used with axolotls
- Size Range: Individual seed pods approximately 1–2 inches long and 1/2 -1 inches in diameter
- Quantities: 10 pods per package
Arjuna Pods for Aquariums & Vivariums
Arjuna Pods belong to the Terminalia genus, the same family that produces Indian Almond Leaves, and they carry many of the same ecological properties, but in a very different physical form. As the pods condition and they become colonized by beneficial bacteria and fungi, they help us aquarists mimic the natural accumulation of seed debris on the forest floor of tropical riparian zones, as we would find in our fish's natural habitats. This scattered distribution recreates microhabitat complexity in aquarium substrates, allowing small fish, shrimp, and invertebrates to live in an aquarium that more closely mimics their natural environment.
As Arjuna Pods break down into detritus, they develop beneficial biofilm across their fibrous surfaces, creating a consistent grazing source for freshwater shrimp. The high lignin content of these pods grows biofilm particularly well, with shrimp and microfauna returning to pods repeatedly as microbial populations establish and cycle. This grazing behavior mirrors what occurs in the wild, supporting invertebrate communities that form the base of the food web.
The medium levels of tannins released by Arjuna Pods enable them to be used across all low-, medium-, and high-tannin aquariums, without the more intense initial tannin load of higher-tannin botanicals, such as catappa leaves. To reduce their tint contributions to your botanical method aquarium, just give them an extra-long initial boil or soak when following the preparation instructions. They can be layered with Indian Almond Leaves, catappa bark, and other Terminalia-family materials to create a diverse and ecologically coherent substrate zone.
Beneath the Leaves: Terminalia arjuna in the Wild
The Arjuna tree grows along the banks of rivers and streams across South Asia, its roots often partially submerged during seasonal flooding. In Sri Lanka, where these pods are sourced, the tree is deeply embedded in riparian forest ecology. Its seed pods, leaves, and branches fall directly into the waterways below, carried downstream, and settle into the leaf litter zones that shelter small fish and invertebrates. The Terminalia family's chemical profile, rich in tannins, humic substances, and antioxidants, has shaped the water chemistry of these streams over millennia, and the organisms living within them have adapted accordingly.
In the aquarium, Arjuna Pods allow us, as aquarists, to recreate this allochthonous input of canopy-derived material falling into the water and becoming part of the substrate. The same processes that play out on a streambed in nature can unfold at the bottom of our aquarium, well, almost the same, with canopy materials softening, biofilm development, detrital accumulation, and the slow return of botanical materials to the ecosystem. Mother Nature knows best.
Sustainability Note:
This product's packaging is home compostable. Just like the botanicals inside, it will break down naturally and return to the soil, because what supports your ecosystem should minimally impact our planet.
Not for human consumption. Preparation required.
This is a natural product, and variation in size, shape, and segment separation between pods is expected.
Arjuna Pods | Terminalia arjuna
Home is getting more natural
While the aesthetic appeal of botanicals and tinted water can be quite attractive to us, the recreation of nature to emulate water conditions, feeding patterns, spawning displays, and territory building are the true benefits botanicals provide to our critters.
Botanical FAQs
Compostable Packaging Promise
Our packaging is designed to return safely to the Earth, just like the botanicals inside. Every bag is BPA- and Phthalate-free, GMO-free, and contains no animal products. Each meets ASTM D6400 composting standards, ensuring it can fully break down in a home compost bin.
What are the Fluffy White Growths on my Botanicals?
That’s biofilm and fungi—what we call the “goo phase.” It’s one of the clearest signs that your aquarium is alive and functioning. These growths wax and wane naturally as botanicals decompose. They’re harmless, even beneficial, and will disappear on their own once microbial populations stabilize.
Will botanicals lower the pH of my water?
That depends entirely on your source water. In very soft or RODI water, botanicals can gradually lower pH as tannins and humic substances accumulate. In medium to hard tap water, buffering capacity often resists these shifts, and you may not notice much change. At Betta Botanicals HQ, our very hard water (350+ ppm) shows almost no pH change unless we use botanicals like Alder Cones or Macaranga Leaves.
When should I replace leaves or pods in my tank?
We recommend allowing botanicals to fully break down into detritus, since this fuels microbial life and enriches the substrate. You can remove them once they stop tinting the water, but you’ll lose some of their ecological benefits. Each time you add new botanicals, follow proper preparation and observe your livestock until you learn your aquarium’s rhythm.
Are your products just for bettas?
Nope. Our botanicals are safe for almost all aquariums, terrariums, vivariums, and paludariums. The only exceptions are goldfish and axolotls, which may ingest small pods like alder cones or casuarina cones. For those species, we recommend large leaves such as Indian Almond, Loquat, or Jackfruit.
What are Tannins?
Tannins are natural compounds released by leaves, seed pods, and bark as they decompose in water. They soften water, gently lower pH, and create the characteristic tea-stained tint found in blackwater habitats. But their role goes far beyond color—tannins fuel beneficial bacteria, fungi, and biofilms, which form the foundation of a healthy ecosystem. They also offer mild antifungal benefits and help reduce stress in fish by replicating the natural conditions they’ve evolved in. At their core, tannins are plant-derived antioxidants that connect your aquarium to the same processes at work in wild flooded forests and streams.