(not from the net!)
I love this plant. It is a great space-filler, looks lovely and grows extremely fast. I usually have to trim them weekly. When the plant grows to the top of the aquarium, just cut it at the midsection and replant. They produce very small, weak roots however and are easily uprooted by inquisitive fish. I have sand as the top layer in my substrate so I had to pile some gravel around these to keep the cory's from uprooting them. Planting these is not necessary. They can be tied to driftwood or rocks. I've found if you keep them in dense enough clumps it doesnt't even matter if some of them get uprooted as the ones around the uprooted one keep it from floating to the surface. As a final note, the only way I got these plants to thrive was to use CO2 injection. Otherwise they just fell apart. I used the do-it-yourself CO2 method of yeast fermentation.
Cabomba caroliniana is considered an invasive species throughout most of the USA. The leaves excrete a geletinous mucous which I theorize might be a source of an allelochemical. In nature it grows in dense clumps by rhizome propagation only in direct sunlight. It is important however, in the aquarium that the stems not be planted closely together. Preferring slightly acidic water with a low GH, it has also been known to grow in a pH of 8.0, as it does in my tank. Cabomba is a heavy water column feeder. And no it doesn't need to be planted into the substrate. Don't plant if you have a Calcareous substrate, as it will kill the plant. It prefers stagnant and slow moving water, but tolerant of turbulent water movement. Don't worry too much about decaying plant matter, it is a natural chelator for heavy metals.
Great plant, I love it. I see a lot of people have troubles with it breaking. It is somewhat weak, but I honestly don't have any trouble with it breaking or just falling apart. It's kept in a 160 L tank, decent lighting using 3 tubes from Aqua-glo and I have also managed to get it to flower. Some fish do like to snack on it at times, but its dense foliage means it's never visible. You can cut it, stick it anywhere and it grows, which I find great. On another note, I use a very fine grade gravel, which might help it out somewhat. I have tried it in a tank with your average grade gravel and the stems tend to rot and break apart. Maybe that's why some people have so much trouble with it.
Nice plant and great for tall tanks. I am trying to replicate memories of oceanic kelp forests with this tall plant, now over 70 cm and climbing. Takes a while to root indeed. I helped this process by planting parts of the stem that have aerial roots in the water column already. Once these roots take the plant does fine. It does seem to be showing some sort of nutrient deficiency, likely nitrates as these are low. Be patient with this one and keep the clones going all the time so it isn't a big deal if you lose a plant due to leaf loss.
I had one green cabomba plant and I had absolutely NO success with it. They are great plants, but they need to be kept in a big aquarium! I tried one in a 4 L bowl with my betta and he loved it, but I had to clean the tank at least once every two days because it was losing all of its branches or whatever you wanna call it. My experience was bad, but they do great in larger aquariums. Happy fishkeeping!
This plant is currently my third favorite plant in my tank, after Java Moss and Java Fern. It does well in a sand substrate, as gravel may not hold it in place. Also, if you plan on using this plant, don't get any big fish such as Cichlids, Gouramis, etc, as they will destroy it. I have it in a tank full of Tetras and Cories and it's just wonderful to look at. I agree that the leaves do tend to aimlessly drift throughout the tank and ending up clogging your filter, but you can remedy this situation by simply removing the leaves on a daily basis. It takes 2 seconds.
I've always had success with this plant in my 115 L tank with bright lights and CO2 (2 bubbles/second). I rarely fertilize this tank as I have algae problems as a result, but the plants seem to flourish despite this. This particular plant did something I've never seen in similar species of stem plant: it began to spread horizontally across the substrate by producing runners which would take root every few inches and sprout a new stem at each root section, effectively choking out my hairgrass which had taken YEARS to cover the bottom in similar fashion. Needless to say, the cabomba had to go. I pulled out every piece in the tank, and now, months later, a single, inch-tall shoot appeared amongst clusters of rotala and milfoil. Since then, this plant's resilience has more than earned its place in my limited tank-space. In response to other comments posted on these pages about weak or thin stems, broken leaves, etc., the answer is water current. True for most all species of stem plants, (and others) a slow current will produce thick stems and broad, sturdy leaves. Fast currents provided by powerheads, canisters, etc. will have the opposite effect. An example of this is in the area where I live in the Southern Appalachians, where the Dept. of Agriculture has introduced anacharis to the New River to counterract high phosphate levels from runoff from Christmas tree farms (a booming business in this area). Most of the anacharis in the river is characteristically thin, with only the tiniest of leaves, while small pools and eddies with virtually no water movement yield plants with the more desirable thickness and larger leaves.
Looked great for a while, but the plant keeps breaking up in my tank, getting caught not only in the intake filter, but also on my driftwood, other plants, etc. It's almost impossible to collect all the dead leaves. I've had to not only remove the plant, but also remove several other plants to clean them (where the dead leaves seem to catch due to the shape of the leaves). I would not consider it again.
These pages have enough comments to give the reader a basic idea on the topic. Further comments are still very welcome (through the site's contact form) as long as they provide new and/or advanced information not yet discussed in the existing ones.