Water sprite

Overview

Water sprite (Ceratopteris thalictroides) is a tropical fern with light green, finely divided, slightly translucent leaves. You can grow it two ways: planted in the substrate, where it forms a tall bush 12-16 inches (30-40 cm) high, or floating, where the leaves broaden and the roots hang down like a curtain. It grows wild in tropical wetlands of Asia and other warm regions.

It is one of the most rewarding plants for beginners: it grows fast, soaks up nitrate, competes with algae from day one and gives fry and shrimp plenty of cover. In Europe it is also a legal, highly recommended alternative to floating plants that are now banned there.

Care and tank setup

Water sprite does well in almost any cycled tropical tank of 10 gallons (40 liters) or more. What it dislikes is low light and, when floated, a choppy surface.

• Planted: bury only the roots, never the crown, or it will rot. It works well in the background or along the sides.
• Floating: aim the filter outlet at the glass and keep it to no more than half the surface.
• Light: moderate; in dim tanks the leaves come in thin and pale.
• Tankmates: great with guppies, bettas, gouramis, tetras and shrimp. Goldfish, large cichlids and some herbivores shred it.

The leaves are delicate, so handle it gently. If it suddenly falls apart, the usual causes are a sudden water change, a nutrient shortage or a copper-based medication.

Fertilizing and trimming

Because it grows so quickly, it appreciates a weekly dose of comprehensive liquid fertilizer with iron and potassium, especially in lightly stocked tanks. When planted, a root tab near the roots helps. Trimming is easy: remove old or yellow leaves at the base and thin out plants when they take over. Every plant you remove takes nitrate and phosphate out of the water with it.

Propagation

It propagates itself through plantlets that sprout along the edges of mature leaves. Once they have a few leaves and roots, they break off and float, or you can detach and plant them yourself. Within a few weeks you will have more than you need. Never dump extras in ponds or streams: give them away, take them to a store or put them in the trash.

Recommended equipment

What you need to keep the Water sprite healthy, checked against Amazon stock.