Red milfoil
Myriophyllum mattogrossense
Also known asMato Grosso milfoil · Red foxtail · Brazilian watermilfoil
Water parameters
Light and nutrients
Substrate type: rooted. Propagation: stem cutting.
Substrate compatibility
| Substrate | pH effect | Nutrient load |
|---|---|---|
| Aquasoil (ADA Amazonia) | lowers pH | very high |
| Dirted tank (mineralized topsoil) (DIY soil substrate) | slightly acidic | very high |
| Mineralized clay substrate (Seachem Fluorite) | neutral / inert | moderate |
| Inert sand (Pool filter sand) | neutral / inert | none |
| Inert gravel (Aquarium gravel) | neutral / inert | none |
With fish
Origin and habitat
A feathery stem plant of the watermilfoil family, Haloragaceae, Myriophyllum mattogrossense (Hoehne), native to western South America and west-central Brazil, including the Mato Grosso region that gives it its name, in slow rivers, ponds and marshes of the wet tropics. The stems are reddish, 30–60 cm long, with whorls of very finely divided bright-green leaves, an even softer, feathery texture than Cabomba, and the upper stem flushes orange to red under strong light. The genus Myriophyllum has over 60 species worldwide, many temperate, but M. mattogrossense is one of the tropical ones that takes well to aquariums and is among the easiest milfoils to grow.
Care notes
Moderate care, and one of the more forgiving Myriophyllum. It does best under medium to high light with regular feeding, and while it grows in low-tech tanks, CO2 makes it faster and denser; aim for ten to twelve hours of light. It is not fussy about nutrients, wanting mainly some nitrate and phosphate, and grows larger and sturdier at moderate nitrate and phosphate levels, with iron and trace dosing bringing out the red tops. Growth is fast, often 5–10 cm a week, so it needs frequent cutting back; propagate from the many lateral shoots by snipping a tip and replanting. The very fine leaves trap detritus, so gentle flow around the plant keeps them clean. It is a tropical species, best around 20–28°C, not a coldwater plant. Its delicate texture is a strong contrast against broad-leaved backgrounds, and it makes a soft, refined background or midground accent that, unlike Cabomba, is fairly easy to keep. It is an ornamental, not a crop, so it is unsuited to media-bed aquaponics or hydroponics.