Borneo Rasamala Root | Altingia excelsa
Borneo Rasamala Root on the Surface:
Borneo Rasamala Root (Altingia excelsa) is harvested from the juvenile root systems of the rasamala tree, a canopy species growing up to 50 meters tall and native to the humid forests of Java, Sumatra, and the surrounding islands of the Indonesian archipelago. Ours is sourced from West Java. These roots are lightweight and durable, with a gnarled branching structure and warm brown to dark brown coloration. Their profile is noticeably thicker than our Melastoma roots. In our botanical method, blackwater, and biotope aquariums they provide surface area for biofilm colonization and territorial definition for a wide range of species.
Essential Details
- Tannin Level: Low to negligible; contributes minimal brown tint
- Tint Color: Yellow/brown
- Durability: Durable; resists breakdown
- Habitat Location: Humid montane and hill forests of Java, Sumatra, and the Indonesian archipelago
- Optimal For: Southeast Asian biotope aquariums, blackwater aquariums, botanical method aquariums, vivariums, terrariums, and paludariums
- Use with Caution: Suitable for all inhabitants
- Size Range: Medium: approximately 8"–12" length, 6"–8" width; Large: approximately 14"–18" length, 6"–8" width
- Quantities: Sold individually as 1 piece or in a 2-pack. This is a natural product, and variation in branching structure, color, and form between pieces is expected.
Borneo Rasamala Root for Aquariums & Vivariums
Rasamala roots are a structural botanical, functioning differently from leaf litter or seed pods in the ecosystem. Rather than contributing to detrital accumulation or tannin output, their primary role is physical: providing structure that supports biofilm development, defines territories, and creates refuge within the water column and substrate zone of our botanical method aquariums.
Once submerged and conditioned, the textured surface of these roots becomes a productive grazing site for biofilms and microbial communities. In aquariums housing shrimps, small loaches, plecos, or suckermouth catfish, these roots serve as grazing habitat and shelter that replicates the submerged roots and snag habitat found along the margins of Southeast Asian forest streams. Shrimp in particular will work the surface continuously as the biofilms regenerate.
Waterlogging is necessary before placement into your botanical method aquarium. Boiling the root, then soaking it in a bucket of water for several days, is the most efficient approach, ensuring you are exchanging the water once or twice during the soak. Some pieces will require longer. Once waterlogged, the root will remain in place on the substrate without anchoring. In vivariums and paludariums, waterlogging is not required, but you should bake the wood to ensure sterilization before placing it inside your enclosures.
These roots pair well with other Southeast Asian materials: Melastoma roots for contrast in scale, Arjuna pods, Sterculia pods, and Jambolan Leaves for tint and habitat.
Beneath the Leaves: Altingia excelsa in the Wild
Altingia excelsa is an evergreen tree reaching up to 50 metres in height across the warmer regions of its Indonesian range, forming part of the upper canopy layer in humid montane forests from the foothills of the Himalayas through Myanmar, Peninsular Malaysia, Sumatra, and Java. It grows in rich, well-drained volcanic soils, where its root systems extend laterally through the forest floor and, along stream margins, directly into the water.
In these environments, exposed and submerged root structures form snag habitat, zones of complexity along stream banks and channel margins where small fish, invertebrates, and aquatic insects concentrate. Organic matter accumulates around root bases, detrital layers build, and microbial communities establish the foundation of the food web. The roots introduced into an aquarium or vivarium help us to mimic this. Mother Nature leads the way.
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 — variation in color, shape, and branching structure between pieces is expected.
Borneo Rasamala Root | Altingia excelsa
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.
