View Full Version : Stem Pant Primer: A How To Guide, Part 1

10-02-2007, 06:53 AM
Almost all extravagant, prize-winning planted tanks in books or on the internet contain stem plants. Yet, stem plants often fail in hobbyists' tanks. In this post I'll show you how to have success with them.
Above all else stem plants need light, and lots of it. A 260 watt fixture of full spectrum light over a 55 gallon aquarium would not be too much. One should aim towards four watts per gallon. And make no mistake, stem plants need a fine, nutrient-rich substrate and 30 to 35ppm of Co2. Commonly available plant substrates are perfect for stem plants. If you wish to use stem plants in your next planted aquarium, these are the bare essentials you need.
Supplemental liquid fertilization would also be helpful.
Now some species.
Cabomba is one of the most commonly available stem plants. C. caroliniana of Central and South America is by far the easiest Cabomba species to keep. It can be kept in any aquarium with a pH between 6.8 and 7.5, with soft to moderately hard water. The brighter the light the more compact and attractive it will be. C. caroliniana's dark green, finely divided leaves look good in the sides and background of larger tanks. It grows quite fast, needing weekly trimming in good conditions.
C. caroliniana, called Green Cabomba in shops, reaches 20 inches tall. It prefers temps between 72-82 (22-28C).
More challenging is C. aquatica, called Yellow Cabomba or Giant Cabomba. It must have soft, slightly acid water and very bright light. Peat filtration is quite helpful.
Is the extra effort worth it? Aquatica is widely thought as one of the most lovely stem plants. Large, greenish-yellow whorls can reach more than two inches across. The leaves must be kept free of debris and fish such as Otocinclus or algae-eating shrimp should be employed in keeping it free of algae.
Plant aquatica stems 2.5 to three inches apart so light can reach the lower leaves. Aquatica reaches more than 16 inches in good conditions. Trimming should be done from the bottom, as those done from the top often don't regrow shoots, and topped plants look unattractive.
A beautiful plant. One of my favorites.
Equally challenging and just as rewarding is C. furcata, the Red Cabomba. Its also listed as C. piauhyensis in older publications, though the former is more usual. Very bright light, Co2 and soft, slightly acid water will reward the keeper with a rusty red-medium green centerpiece in a 40-gallon tank, or a larger grove in a larger container. C. furcata reaches 16 inches tall, occasionally taller in exceptional surroundings.
Generally easier to keep and just as beautiful are the Limnophilas. They usually go by name Ambulia in shops, which is no longer a valid name to science. All Limnophilas are from India, Indonesia and Sri Lanka, save for L. indica from Africa, Asia and Australia.
Dwarf Ambulia (L. sessiliflora) is dwarf only in common name, as sessiliflora reaches 20 inches tall. It is more compact than most of the Limnophilas, adaptable to different water conditions (if extremes are avoided), and is by far the easiest of the group to keep, thus ideal for novice planted tank keepers. It does need a good source of iron and a very bright light, and 72-82 (22-28C) temperatures. It will reward the aquarist with quite fast growth which is noticeable day to day. It propagates by side shoots and runners, making a bush of itself in a short time if happy. Plant the stems about 1.5 inches apart. It does well in harder waters.
UPDATE: L. sessilifora is on the Federal Noxious Weed List, and thus is banned in the United States. Those in other countries may still be able to obtain this plant.
Much larger and more difficult to keep is L. aquatica, the Giant Ambulia of India and Sri Lanka.
Reaching over 20 inches tall, the whorls of aquatica can reach 4.5 inches, making it a dominant plant in smaller aquariums. It needs a good source of iron and strong lighting, both for its health and to keep it more compact, as it has a tendency to get leggy. Trimming can cause aquatica to fail. Left alone, it will spread with new plants from its roots and new shoots on the stem. Spacing them out in groups at the back of aquariums is quite effective. Aquatica prefers 72 to 79 degree temperatures (22-26C).
L. indica is a relatively easy, 16-20 inch plant that does well in most aquariums with strong lighting. There are several species that are sold under this name. Without examination of the flower, positive identification is impossible. However, all can be kept at 72 to 82 (22-28C) degrees and are adaptable to water conditions. Stems should be planted two inches apart so light can reach the lower leaves.
Perhaps the easiest red plant to grow, Alternanthea reineckii provides contrast in the aquarium. If your tank has strong lighting, Co2 and an iron-rich substrate, I wouldn't hesitate to recommend this plant.
Olive green, lanceolate (spear-like) tops over rich purplish-red undersides typify reineckii, but the red will fade in insufficient light. The more light it has, the healthier and more attractive reinecki will be.
It can be cultivated by cuttings, but use sharp scissors to do so, as tearing can cause the plant to recede. Its common name is Red Temple Plant.
Reineckii reaches 20 inches in the best conditions, less in most tanks.
A most satisfying plant, this South American likes temps between 72 and 82 degrees (22-28C).
The water milfoils, Myrophyllium, are one of the best plants for fry finding themselves in a dangerous world. The feathery, fine upward facing leaves are perfect warren for little fish to hide in. It also means the plant must be kept free of debris and algae.
The delicate foxtails (M. aquatica. M. scabatum, M. hippuroides) must be kept in cooler water, between 65 and 74 degrees, with brilliantly bright light. In those conditions, they are very hardy, and develop into beautiful scrolls. Hippuroides of the United States (called the Green Milfoil, the Water Mifoil) can tolerate up to 75 degrees, though it does better in the upper 60's. It reaches 20 inches. Scabatum, called foxtail in the trade, can grow to 2 feet. Given cool water down even down to 65, it is quite hardy. Aquatica may be the king of the cool water aquarium plants, with delicate leaves on a long, graceful stem.
Finding fish to go with these cool water beauties can be a challenge. Goldfish are unsuitable, as they will pick them apart. White Clouds (Tanichthys albonubes) and the exquisite Celestial Pearl Danio (Celestichthys margaritatus) are two options for a 72 degree tank.
For the tropical tank, there are two stars; green myro and red myro.
The latter is M. tuberculatum, from Brazil. It lives in water between 72-82 (22-28C), grows to 16 inches and sports rusty red leaves. It keeps that color in strong light and a low pH, down as low as 5.0 up to 7.5. It is important the water be soft with this species. Iron-rich fertilizers are essential. A similar plant, mattogrossense is sometimes sold as tuberculatum.
Banned in some parts of the US (check with your local government) is the lovely Green Myro (M. aquaticum) of South America. With bright light, a rich substrate, Co2 and iron fertilization, it grows very well, up to 20 inches, and needs to be kept with a low pH 6.0-7.0. It does best in soft water. In very good light it can produce tough leaves above the surface. Temps are 72-86 (22-30C).
Both tropical and temperate milfoils produce side shoots from the stem, but cut these off to replant very carefully, as the parent stems are easily damaged.
Ludwigia, a native of the United States, has long been popular in the aquarium. Given the temperate environment in most of the US, surprisingly, most species do very well in tropical tanks. Several hybrids are available, usually between L. repens and L. palustris. If you see one available as "L. mulletii", an invalid name, it is that hybrid.
Continued in Part 2

10-02-2007, 01:37 PM
WOW, excellent! your fingers must be bleeding from all that typing!

10-02-2007, 02:57 PM
Dave...I nominate you for god.
Your articles are always so good.
One quick question...how would I trim my cobamba?
It is like growing all over the tank and I saw you said you are supposed to trim it near the bottom. I have 2 stalks of cobamba in one corner of my tank and they have grown all the way up to the surface and to the middle of my tank where the light is. I want to trim them down as they are just overcrowding and becoming a mess.

10-03-2007, 09:23 AM
Stem plants do that (get messy) when there isn't enough light/nutrients/Co2. Bright light, 4wpg or better, will keep it compact.
Don't know what lights, wattage/color temp you're using, zack.