How to Grow and Care for African Water Fern

The African Water Fern, known scientifically as Bolbitis heudelotii, is a slow-growing aquatic plant from the rivers of tropical Africa, popular in aquascaping for its distinctive foliage. The plant is characterized by its deep green, finely textured leaves, which have a translucent quality, adding a unique aesthetic to freshwater aquariums. This fern provides a lush, jungle-like appearance and is prized for its steady, manageable growth.

Planting the African Water Fern

The rhizome, the thick horizontal stem where leaves and roots grow, must never be buried under the substrate. Burying the rhizome cuts off its access to oxygen and nutrients in the water column, leading to rot and the eventual death of the plant.

There are two primary techniques for securing the fern. The first is attaching it to hardscape like driftwood or porous rocks with cyanoacrylate super glue gel or by tying it loosely with fishing line or cotton thread. Over time, the fern develops anchor roots that grip the surface, and the thread can be removed.

An alternative method is to place the fern on top of the substrate. If the plant is buoyant, a small weight can hold the rhizome down without burying it. This allows the roots to grow into the substrate for anchorage while the rhizome remains exposed. Ideal placement is in the midground of the tank for moderate water flow and light.

Required Water and Light Parameters

The African Water Fern prefers low to moderate lighting. High-intensity light is detrimental because its slow-growing leaves become a surface for algae, which inhibits photosynthesis. A daily photoperiod of 8-10 hours is sufficient.

The fern thrives in soft, slightly acidic water. The ideal temperature range is 71–82°F (22–28°C), with a pH between 5.0 and 7.0. Water hardness (GH) should be kept low, under 6 dGH, as the plant can struggle in hard, alkaline water. It is adaptable to a range of conditions if changes are not sudden.

Carbon dioxide (CO2) injection will improve the fern’s health and growth rate. As a plant that draws nutrition from the water column, it benefits from a comprehensive liquid fertilizer providing macronutrients and micronutrients. Because the rhizome is not buried, substrate-based fertilizers or root tabs are ineffective.

Pruning and Propagation

Pruning involves trimming any old, yellowing, or decaying leaves with sharp, clean scissors as close to the rhizome as possible. This practice directs the plant’s energy toward producing new, healthy fronds.

Propagation is achieved through rhizome division. Using a sterile razor blade or sharp scissors, cut the rhizome into smaller sections. Ensure each new piece has a healthy portion of the rhizome and at least a few leaves attached.

The new sections can be planted using the same methods as the parent plant, either attached to hardscape or placed on the substrate. Newly propagated plants exhibit a brighter green color than the established parent, adding a pleasing contrast.

Troubleshooting Common Problems

The plant may “melt” or lose its leaves after being introduced to a new aquarium. This is a stress response to the change in water parameters. If the rhizome remains firm and healthy, the plant will recover and produce new leaves once it has acclimated.

Slow or stunted growth is linked to a deficiency in care parameters. Insufficient lighting or a lack of nutrients from a liquid fertilizer are common culprits. Reviewing your lighting schedule and fertilization routine can resolve this issue.

Black, brown, or transparent patches on the leaves indicate poor health or decay. This can be caused by a buried rhizome or a severe nutrient deficiency. Inspect the planting and ensure the rhizome is fully exposed to the water column.

Algae growing on the leaves indicates that the lighting is too intense or the duration is too long. Reduce the light intensity or shorten the daily photoperiod to manage this problem. Placing the fern in an area with good water circulation also helps deter algae from settling on its leaves.