Cabomba

Quick facts

Max height

80 cm

Growth rate

fast

Difficulty

intermediate

Placement

background

Propagation

cuttings

Water parameters

Temperature

18–26°C

pH

6.0 to 7.5

Hardness

2 to 12 dGH

Cold water

tolerated (unheated setups)

Light and nutrients

Lighting

high

CO2

not required, but boosts growth and color

Substrate

nutrient preferred

Feeding

feeds from both water column and roots (liquid ferts plus root tabs)

Substrate

What this plant roots into (or attaches to). The substrate affects both plant nutrition and water chemistry; see each linked page for full effects.

This plant feeds primarily from the water column, so substrate choice matters more for its fish-tank compatibility than for plant nutrition.

With fish

Plant-eating fish

will be eaten by mollies, silver dollars, large goldfish, and other plant-grazers

Diggers (corydoras, loaches)

may get uprooted by active diggers

Root-disturbing fish

sensitive to root disturbance, plant where roots stay undisturbed

Habitat

Native to slow-moving freshwater across the Americas, from the southeastern United States through Central America to South America. The genus Cabomba includes several species (C. caroliniana, C. aquatica, C. furcata) with similar fan-shaped, finely divided submerged leaves that create a feathery, intricate texture. The most common species in the aquarium trade is C. caroliniana (green cabomba). The plant grows as long, soft stems with whorls of fan-shaped leaves at each node. In the wild, it forms dense underwater meadows in ponds, slow rivers, and lake margins. Cabomba is widely available and inexpensive but has a reputation among experienced hobbyists as a plant that looks great at purchase and then deteriorates in many home tanks.

Outdoor pond use

This species transitions to outdoor ponds well, not just indoor aquariums.

Outdoor pond zones (USDA)

5 to 11 (winter low around -29°C or warmer)

Below the minimum zone, the plant won't overwinter outdoors but can still be grown seasonally and overwintered indoors. Several pond-friendly species (water hyacinth, water lettuce, parrot's feather) are regulated as noxious in some jurisdictions; check the legality data on the profile before releasing anything to an outdoor body of water.

Care notes

The reputation for difficulty is partly deserved: Cabomba needs more light than many beginners expect. Under low light, the fine leaves at the bottom of the stem die, the plant becomes leggy and bare, and it eventually disintegrates. Medium to high light (50+ PAR at the plant) keeps it healthy. CO2 injection significantly improves growth and prevents the lower-stem dieback that frustrates keepers. In a high-tech setup with CO2 and good light, Cabomba grows fast and looks spectacular, with dense, feathery growth that sways in current. Without CO2, it can still work under strong light, but growth is slower and the plant requires more attention. Soft to moderately hard water is preferred (GH 3-12); very hard water causes the fine leaves to develop calcium deposits. Plant stems in groups, pushed into the substrate. The fine leaves trap detritus, so gentle water circulation around the plant helps keep it clean. Trim tops and replant to propagate. The cut lower stems may or may not regrow; Cabomba is less reliable at producing side shoots than most stem plants. Because of the moderate difficulty and detritus-trapping tendency, many experienced aquascapers skip Cabomba in favor of easier feathery alternatives like Myriophyllum or Limnophila. But for keepers with adequate light and CO2, it's one of the most beautiful background plants available.

Further reading

• How to cycle a fish tank
• Water chemistry for fishkeepers: pH, GH, KH, and what they mean