When you think of beautiful bunch plants to decorate the aquarium,Cabomba quickly comes to mind. When it grows well,its beautiful,finely cut fan-shaped leaves provide not only a screen for heater,filters,and so on,but also a fine place for smaller fish to shelter.
Cabomba can be grown in the middle or background of the aquarium,but in good conditions it can grow too long pretty quickly. For that reason,try it at the sides of the aquarium in groups of three or four. Allow the stems to grow in toward the center,pruning tehm for cuttings when they are too long.
Don’t crush Cabomba stems together. Give the plants toom so they can grow and expand,and so the light can reach the lower leaves. The main plant never grows emersed,though small floating leaves will often accompany the small emersed flowers.
Taxonomy and Background
Part of the family Cabombaceae,which they share with the seldom-seen geneus Brasenia,five species of Cabomba are generally seen in the hobby. These are C.aquatica, C.caroliniana, C.furcata (piauhyensis),C.haynesii,and C.palaeformis. The previously recognized C.australis is now considered to be a sub-species of C.caroliniana,namely C.caroliniana var.caroliniana.
They originate from Central,North,and South America,with one species in China,but C.caroliniana especially has spread widely and is considered a serious weed in North America (particularly in the West and Southwest,though it now grows as far north as New York and Washington) and is now widespread in parts of Australia,both through inadvertent dumping and delibereate introduction. C.furcata is sometimes found in the wild in North America,but in warmer locations where its more difficult demands can be met (Purerto Rico,for example).
In the wild,C.caroliniana may have stems up to 10 metrers (33 feet) long and has been recorded growing 50 mm (2 inches) in one day. They grow reooted in the mud of water that is stagnant to slow-flowing,including streams,smaller rivers,lakes,ponds,sloughs,and ditches that are 1 to 3 meters (nearly 10 feet) deep. C.caroliniana is able to tolerate a wide range of conditions,including temperate waters. The submerged leaves and stems have a thin gelatinous coating. The leaves of C.aquatica tend to be less finely divided than those of the other species.
Flowers are produced above the surface along small,oval,notched leaves on thin stems. Color of the flowers is dependent on the variety. Flowers of C.caroliniana and C.palaeformis tend to be white,while C.aquatica flowers are yellow,and those of C.furcata are purple.
Cabomba flowers from about May to September (the flowering period is rather longer in the wild,especially in the warmer southern states) and has its maximum growth period in summer. It propagates freely from stem pieces. It is self pollinating,and its seed sets freely in the southern states but doesn’t seem to set further north. The stems are fragile,and since each broken-off piece can become a new plant it rapidly spreads. The flowers are small,solitary,and normally white. Usually they are associated with the small floating leaves. The flowers open in the morning and close in the afternoon,then submerge below the water.
Probably in response to environmental factors,flowers can vary in color; plants with purple-tinted flowers have been called Cabomba caroliniana var.pulcherrima. South American plants with yellow flowers have been called C.caroliniana var.flavida.
Cabomba can be propagated from even very small segments from the main stem. In the aquarium it is best to cut the tops off of the stems that are a few inches long and replant them. Strip off the lowest leaves and push the end into the substrate,or leave to float in a well-lit aquarium,and soon long white roots will form. Healthy plants grow fast and need regular pruning,which will supply all the new plants needed. In long stems growing along the surface of the water,lateral shoots will occasionally arise.
The key to growing good Cabomba is light. For maximum growth,and to bring out the beauty of C.furcata,3 watts per gallon or more is needed,though this intense light is only needed for three to four hours each day. In shady conditions,the stems remain short or become leggy,with the whorls spaced out widely along the rather pale stems,or the lower leaves start to die off. What we want are dense whorls and the beautiful intense green color (or reddish shades in furcata). In addition,keep the CO2 levels up to around 10 ppm,especially for furcata. Cabomba also responds well to above-average nutrients levels. C.caroliniana will tolerate soft or hard water,but C.furcata needs soft,acid water. Both are rather sensitive to water changes,as this tends to reduce the higher nutrient levels they prefer.
In the wild Cabomba grows in muddly situations,so a fertilized substrate definitely aids growth,and it promoted the growth of the fine white roots. Dissolved nutrients (nitrates and phosphates) in the water are important too,and they greatly aid good growth. Hardness, pH value,and temperature (though growth seems to slow as the temperature reaches about 80° F) seen fairly unimportant for C.caroliniana. C.furcata prefers the water to be warmer and softer. If anything it needs even more light to achieve its attractive reddish-purple color.
The problem with this well-lit nutrient-rich environment can be algae. Once algae blooms and gets into the Cabomba whorls,it is hard to eliminate-although it will do them no harm unless it becomes really excessive. In a balanced,well-planted aquarium,the fast growth of Cabomba and others will help deter algae.
Lack of nutrients and CO2 leads to weak growth and easily broken poor-looking stems,and the broken pieces can block filters. Heavy water circulation from powerheads can also cause broken stems and bits of the whorls clogging filters. Cabomba prefers a quiet or gentle circulation. Also,keep the water well filtered,otherwise floating debris will be caught by the fine leaves and look very unattractive.
v The shades of color of Cabomba are variable under different environmental conditions. Flowers are required to define the true species.
v Cabomba furcata is often offered in the trade as C.piauhynsis, C.warmingii, C.pubescens, C.plaeformis, or C.australis and may be called red Cabomba or purple fanword
v Cabomba aquatica is offered by some of the Far Eastern suppliers as green Cabomba,but it is uncertain if it is the true species.
v Varieties offered in the trade,such as the so-called yellow Cabomba, C.asiatica (which is not yellow but green),are almost certainly forms of Cabomba caroliniana. Other forms are silver queen and various “varieties” called multipartite,paucipartita,and pulcherrima.
v Where Cabomba just will not thrive,consider Ceratophylum,Hottonia,Limnophila,Myriophyllum,or Synnema. All prefer bright light but are easier as to water conditions and will generally grow whrere Cabomba languishes.