Fast-growing aquarium plants

Fast growers pull nutrients out of the water before algae can use them, which makes them the cheapest algae control there is. Expect to trim regularly. Profiles list light, CO2 and growth rate for each species.

Height: 0–59.1 in; 0 in (0.1 cm) to 59.1 in (150 cm); half the list stays at 15.7 in (40 cm) or under
Temperature: 68–82°F; 20–28°C, most of the list
Light: 13 low light; 82 medium light · 54 high light
CO₂: 47 no CO₂ needed; 77 CO₂ beneficial · 25 CO₂ required
Difficulty: 91 easy; 39 medium · 19 difficult

123 plants and 27 varieties

Fast growers that need nothing

Hornwort, guppy grass, Hygrophila polysperma, jungle val, waterweed and water sprite are among the beginner plants with low or medium light and no CO₂ need. They grow in a bare tank with a shop light, they soak up the nitrate a new tank produces, and they give fry somewhere to hide. Hornwort and guppy grass do not even need planting. Drop them in and they float or sink and grow either way. Hygrophila polysperma is a US federal noxious weed, and bringing it into the country or across state lines needs a USDA permit. Guppy grass and waterweed are marked invasive, so put their trimmings in the trash.

Stems that fill a background in weeks

Rotala rotundifolia, ambulia and Ludwigia palustris are marked easy, and Hygrophila corymbosa is marked beginner. Plant a bunch, cut the tops off when they reach the surface, and replant the tops beside the parents. Within a month you have a wall. Bacopa australis is a midground stem instead. It reaches 15.7 inches (40 cm) and creeps sideways under bright light. Rotala and ludwigia color up toward red under stronger light and with iron in the fertilizer, and stay green without. Rotala rotundifolia and ambulia are marked invasive, so put their trimmings in the trash. Ambulia is also a US federal noxious weed, and bringing it into the country or across state lines needs a USDA permit.

Floating fast growers

Frogbit, dwarf water lettuce, salvinia and red root floater grow faster than anything rooted because they take carbon dioxide straight from the air. They shade the tank, which many fish appreciate, and they pull nutrients out of the water faster than any filter. The cost is that they need thinning every week or the plants below them go dark. Amazon frogbit, dwarf water lettuce and Salvinia natans are marked invasive, so never release them or dump them outdoors.

Fast but demanding

Rotala macrandra and wallichii, Ludwigia inclinata and its Pantanal form, red cabomba and glosso are also rated fast, and they are rated difficult. They want high light and injected CO₂ and a steady fertilizer routine, and when one of those slips they decline as fast as they grew. Fast growth means fast feedback, which is a virtue in an experienced keeper's tank and a trap in a first one. Red cabomba is marked invasive, so put its trimmings in the trash.

What fast growth costs you

Fast growers eat. In a tank without fertilizer they show it as pale new leaves and holes in the old ones, potassium and iron running short before nitrogen does. Expect to trim weekly, to pull handfuls of floaters, and to fertilize once the fish waste stops being enough. The trade is a tank that stays clear of algae with very little scrubbing.

By the numbers

Smallest

Tallest

Easiest to grow

No CO₂ needed

Low light

FAQ

Common questions

Do fast-growing plants really reduce algae?

They compete for the same nutrients and light, so a tank stuffed with fast growers has less algae than the same tank without them. They are not a cure for too much light or too much food, and a shaded tank grows less of everything.

Which fast-growing aquarium plants need no CO₂?

Hornwort, guppy grass, jungle val, Vallisneria spiralis, waterweed and water sprite are among the plants that list no CO₂ need. Every floating plant here does too, except Riccia fluitans, floating pennywort and the mosaic plant, which list CO₂ as beneficial.

What is the fastest-growing aquarium plant?

The floaters, because their leaves sit in air. Duckweed, frogbit and salvinia can double in a week in a well-lit tank. Hornwort, guppy grass and water sprite keep pace under the surface.

How often do fast-growing plants need trimming?

Weekly in a well-lit, fertilized tank, every two weeks in a low-tech one. Cut stems above a leaf node and replant the tops if you want more plants.

Can fast-growing plants live in low light?

Yes, a good number of them. Hornwort, guppy grass, Hygrophila corymbosa, jungle val, giant val, Elodea canadensis and duckweed are among those that list low light.

Do fast-growing plants need fertilizer?

Eventually. A lightly stocked tank feeds them for a while, then new leaves come in pale or full of holes. A weekly all-in-one liquid fertilizer, and root tabs for the swords and vals, keeps them going.

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