Ceratophyllum demersum "Mexiko" ("Rotstängelig")

Species description

Care, breeding and tankmates

Plant profile

Placement

Midground

It is highly versatile and can be used as a floating plant to diffuse intense lighting or anchored to hardscape materials. Care should be taken not to plant the stems deep into the substrate, as the lack of true roots will lead to rotting.

Botanical form

Stem

This variant is distinguished by its potential to develop striking reddish or brownish stems under strong light. The needle-like leaves remain dense and bushy, creating a beautiful contrast against the colored stems.

Growth

very-fast

It grows very rapidly, though sometimes slightly more compact than the common form depending on lighting. Constant trimming is usually required to manage its vigorous expansion.

Substrate

None

The 'Rotstängelig' (red-stemmed) variety of Ceratophyllum demersum from Mexico is completely devoid of true roots, making substrate composition irrelevant for its nutritional needs. It grows vigorously while floating freely, pulling nitrogen and other compounds directly out of the water. To keep it stationary, the stems can be gently tucked into any standard aquarium gravel or secured to hardscape. It is crucial not to plant the stems too deep into the soil to prevent decay.

Column fertilization

Recommended

Complete reliance on water column fertilization means it benefits greatly from regular dosing of comprehensive liquid fertilizers. Adequate iron dosing can help enhance the attractive reddish hues of its stems.

Root fertilization

None

Root tabs are ineffective for this plant as it lacks a root system for substrate nutrient extraction. All nourishment must be provided via the water column.

Trimming

Occasional

To trim, simply cut the top portions of the stems and remove or replant them. It is important to regularly thin out dense floating mats to ensure sufficient light reaches the lower areas of the tank.

Propagation

Cuttings

It propagates effortlessly by vegetative fragmentation, where any broken stem piece can quickly grow into a full plant. This makes it very simple to multiply and share with other hobbyists.

Sensitivity

Moderate

It shares the same sensitivity to liquid carbon supplements and certain fish medications as the common Hornwort, reacting by dropping its needles. It typically adapts well to a wide range of water parameters but appreciates clean, well-oxygenated water.

Layout role

Midground, Background

The reddish stems make it an interesting focal point when used as a background plant or a floating element. It provides excellent cover for fry and shrimp while adding a subtle splash of color to the upper levels of the aquarium.