Curly Waterweed (Lagarosiphon major)

Species description

Care, breeding and tankmates

Plant profile

Placement

Background

Given its potential to grow very tall and bushy, it is best placed in the background of the aquarium. It can be planted in dense clusters to quickly create a lush, green backdrop. It's also suitable for coldwater tanks and ponds due to its adaptability.

Botanical form

Stem

It features relatively thick, brittle stems with strongly recurved, dark green leaves that spiral densely along the stem. The plant has a robust, somewhat stiff appearance compared to other stem plants. Under bright light, the growth becomes very compact, creating a thick, rope-like look.

Growth

Fast

This plant has an exceptionally fast growth rate and can easily take over an aquarium if left unchecked. Regular and sometimes aggressive trimming is required to keep it from shading out other plants. Its rapid growth is highly beneficial for competing against algae and oxygenating the water.

Substrate

None

Lagarosiphon major can grow vigorously without any substrate, absorbing essential minerals and nutrients directly through its leaves and stems from the surrounding water. If placed in the substrate, it uses fine gravel or sand merely as a physical anchor rather than a nutritional source. It can be easily cultivated either by floating freely or by lightly burying the lower stem portions in a shallow layer of inert substrate.

Column fertilization

Recommended

It draws the vast majority of its nutrients directly from the water column through its leaves and stem. Because of its fast growth, it can quickly deplete nitrates and phosphates in the water. Regular column fertilization is beneficial but often not strictly necessary in moderately stocked tanks.

Root fertilization

Optional

Root fertilization is generally unnecessary for Lagarosiphon major. While it does produce fine white roots to anchor itself, it doesn't rely heavily on substrate nutrients. It can even grow well if left floating freely in the water.

Trimming

Regular

Trimming is straightforward: simply cut the stem anywhere along its length. The lower portion will often branch out and produce new side shoots, making the bush denser. The cut tops can be replanted to easily expand the group.

Propagation

Cuttings

Propagation is incredibly easy and occurs through simple stem cuttings or by the plant naturally branching out. Any broken piece of the stem with a few healthy leaves can grow into a new plant. It also produces lateral shoots that can be pinched off and planted.

Sensitivity

Moderate

It is highly resilient and not particularly sensitive to water parameters, tolerating hard water and a wide pH range. It prefers cooler water temperatures and can struggle if the aquarium is kept constantly above 26°C (79°F). In very warm water, the stems may become thin and brittle.

Layout role

Background

It serves primarily as a fast-growing, dense background plant that provides structure and bright green color. Its robust nature makes it ideal for setups with active or herbivorous fish that might damage more delicate plants. It is excellent for creating a wild, natural jungle look.