Anacharis

Overview

Anacharis is the classic beginner and goldfish plant - a fast, leafy stem plant sold in cheap bunches almost everywhere. In the trade the name covers Egeria densa (Brazilian waterweed) and sometimes true Elodea; care is near-identical. It grows quickly in cool, ordinary water and eats nitrates for a living. The honest caveat: it is a regulated invasive in parts of the US and elsewhere, and it can fall apart in very warm, dim tanks.

Origin & Natural Habitat

Egeria densa is native to South America (Brazil, Argentina, Uruguay) in slow rivers and lakes. Introduced populations now choke waterways on several continents - it is a major weed in California's Delta and in New Zealand, and it sits on the Washington and Oregon quarantine lists as a Class B noxious weed, where selling or shipping it is illegal. Check your local rules before buying, and never release aquarium plants into waterways.

Appearance

Bright green stems with dense whorls of small, slightly curled strap-like leaves, growing as upright columns that branch freely. Bunches quickly turn into a leafy thicket; roots are thin, white and optional.

Why People Grow It - Qualities & Benefits

• Very fast, forgiving growth in unheated tanks
• Excellent nitrate sponge for new setups and ponds
• Cheap and available nearly everywhere
• Good cover for fry; goldfish tolerate it better than most plants

Care

Light: Moderate. It survives low light but gets pale, stringy and sheds lower leaves; good light keeps it dense.

Water: Prefers cool to mild, roughly 16-24°C; it manages in tropical tanks but often weakens above about 26°C long-term. pH 6.5-8.0, tolerates hard water well.

Substrate: Optional. Float it, or plant stem bundles loosely - buried ends sometimes rot, and the plant regrows from the healthy upper stem anyway.

CO₂ & feeding: Not required. It feeds from the water column; a basic liquid fertiliser prevents pale, stunted tips in clean tanks.

Placement: Background thickets, pond bunches, or floating in breeding tanks.

Extra: ⚠️ Legal status matters with this plant. It is banned or regulated in several regions; buy locally compliant stock and bin all trimmings.

Propagation

Cut healthy stems into sections of 15 cm or more and replant or float them - every piece grows. Trimmings must go in the bin, never down drains or into ponds connected to waterways.

Common Problems & Pests

Falling apart in warm, low-light tanks (bare stems, dropped leaves); rotting buried stem ends; snails riding in on cheap bunches. Goldfish and large cichlids will still eat or shred it, just more slowly than they destroy softer plants.

Toxicity & Safety

Not known to be toxic to cats, dogs or aquarium livestock. Shrimp-safe.

Best Suited For

• Beginners with unheated or coldwater tanks
• Goldfish keepers and pond owners (where legal)
• Cycling and breeding tanks
• Anyone needing fast growth with no equipment

FAQ

Is anacharis legal where I live?

It depends. Egeria densa is a listed noxious weed or prohibited species in several US states and countries because escaped plants choke waterways. Check your state or national invasive species list before ordering online.

Why is my anacharis disintegrating in my tropical tank?

Warmth plus dim light is the usual cause - it is naturally a cool-water plant. Move it closer to the light, keep the tank at or below about 26°C, or choose a true tropical stem plant instead.