Cabomba
Cabomba caroliniana
Also known asGreen cabomba · Carolina fanwort · Fanwort
Water parameters
Light and nutrients
Substrate type: nutrient preferred. Propagation: cuttings.
Substrate compatibility
| Substrate | pH effect | Nutrient load |
|---|---|---|
| Aquasoil (ADA Amazonia) | lowers pH | very high |
| Mineralized clay substrate (Seachem Fluorite) | neutral / inert | moderate |
| Dirted tank (mineralized topsoil) (DIY soil substrate) | slightly acidic | very high |
| Inert sand (Pool filter sand) | neutral / inert | none |
| Inert gravel (Aquarium gravel) | neutral / inert | none |
With fish
Origin and habitat
A fine-leaved aquatic perennial of the family Cabombaceae, native to southeastern South America, in southern Brazil, Paraguay, Uruguay and northeastern Argentina, and to parts of the United States. The genus Cabomba holds several species, including C. caroliniana, C. aquatica and C. furcata, all with fan-shaped, finely divided submersed leaves in whorls along soft stems, giving a feathery texture; C. caroliniana, green cabomba, is the common one in the trade. In the wild it forms dense underwater meadows in ponds, slow rivers and lake margins. Spread through the aquarium trade, it has become a damaging invasive abroad, listed as a Weed of National Significance in Australia, where it chokes east-coast waterways, and naturalised across Europe. It is cheap and widely sold but has a reputation for looking superb at purchase then declining in many home tanks.
Outdoor pond use
- USDA zones
- 5–11 (winter low around -29°C or warmer)
Care notes
Its difficulty is real and mostly about light and water chemistry. Cabomba needs bright light, roughly 30 to 40 PAR or more for the green form; under low light the fine lower leaves die, the stem goes leggy and bare, and the plant falls apart. CO2 is not strictly required but makes a big difference, roughly doubling growth and sharply raising the odds of success, and leaf drop most often signals a CO2 shortfall. It is fussy about water: keep it soft to moderately hard, pH 6 to 7.5, since hard water above about 8 GH, high pH, or temperature shock from water changes all trigger melting. Plant stems in groups pushed into the substrate, give gentle flow so the feathery leaves do not trap detritus, and propagate by terminal cuttings of 10–12 cm trimmed below a node, though the cut lower stems regrow less reliably than most stem plants. Many aquascapers skip it for easier feathery plants like Myriophyllum or Limnophila, but with strong light and CO2 it is one of the most beautiful background plants. Note the legal side: because it is so invasive, C. caroliniana is banned as a Weed of National Significance in Australia and restricted in parts of the US and Europe, so check local rules and never release it into the wild. It is an ornamental, not a crop, and unsuited to media-bed aquaponics or hydroponics.