The Anubias genus is a highly favored group of aquatic plants among freshwater aquarium enthusiasts, celebrated for its hardiness and appealing deep green foliage. These plants tolerate a wide range of water conditions, making them popular for beginners and experienced hobbyists alike. Anubias does not need to be planted in the substrate; burying the entire plant can actually lead to its demise. This unique requirement is due to the plant’s specific anatomy, which has adapted to a different method of nutrient uptake and anchoring.
The Critical Role of the Rhizome
The biological reason Anubias cannot be fully planted lies in its specialized stem structure, known as the rhizome. This is a thick, horizontal stem from which the roots grow downward and the leaf stalks grow upward. In its native West African environment, Anubias grows as an epiphyte, naturally attaching to rocks and driftwood with the rhizome exposed to the water column. The rhizome is designed to absorb oxygen and nutrients directly from the surrounding water, not from the substrate. If buried beneath gravel or sand, it becomes deprived of oxygen and water flow, leading to suffocation and decay known as rhizome rot. To keep Anubias healthy, the entire rhizome must remain completely above the substrate line, though the fine roots can grow into the base material.
Securing Anubias Without Substrate
Since the rhizome must remain exposed, Anubias is secured to hardscape elements like driftwood or porous rocks. This mimics the plant’s natural anchoring behavior and provides a stable base for the roots to attach permanently. There are three main successful methods for attaching these plants without damaging the sensitive rhizome.
Using Cyanoacrylate Glue
The most popular method involves using cyanoacrylate, commonly known as super glue, specifically the gel formula. This adhesive is non-toxic once cured and provides an instant, secure bond when applied to the rhizome and pressed onto a dry spot on the hardscape. Only small dabs of the gel are necessary, and care must be taken to only glue the roots or the bottom of the rhizome without covering any emerging leaves.
Tying with Thread or Line
Another common technique is tying the plant to the hardscape using thin, dark cotton thread or fishing line. The thread is carefully wrapped around the rhizome and the attachment point, snug enough to hold the plant firmly but not so tight as to cut into the stem. If cotton thread is used, it will naturally dissolve over a few weeks, allowing the roots time to grip the surface.
Wedging into Hardscape
The final method is simply wedging the plant into a natural crevice or gap within a piece of driftwood or rock formation. This is the least invasive technique but requires a hardscape piece with a tight enough opening to hold the plant securely.
Basic Care Requirements for Optimal Growth
Once Anubias is correctly anchored, its reputation as a low-maintenance plant is well-earned, as its growth requirements are modest. It thrives best under low to moderate lighting conditions, consistent with its origin on shaded riverbanks. High-intensity lighting should be avoided because it promotes the growth of algae, particularly green spot algae, on the broad, slow-growing leaves.
The plant’s slow metabolism means it has low nutrient demands and primarily absorbs what it needs from the water column. Liquid fertilizers can enhance growth, but they are not necessary unless the water column is nutrient-deficient. Anubias is highly adaptable to standard tropical aquarium water parameters, tolerating a wide pH range of 6.0 to 8.0 and temperatures between 72°F and 82°F (22°C to 28°C).