This covers a
variety of topics related to live plants in the aquarium.
Stem plants | Rosette plants | Mosses and ferns | Floating plants
Lights, CO2, filtration and other
accessories| Planting
| Cuttings
Plant types.
Stemmed
plants. These can have several leaves, pairs of
leaves or single, alternate leaves growing along a stem. They are probably the
easiest plants to grow and can be large and fast growing. Leaf nodes, where the
leaf joins the stem, can produce leaves, roots or new shoots. Simply snap the stem,
plant it with at least one node buried and you have a new plant. The original
plant will then grow a new shoot, or shoots, from the top node on the remaining
stem. One of the commonest, Cabomba can reach 6m. in length if it has the space
and can grow visibly in a day.
Hygrophila
polysperma and H. polysperma ‘sunset’ with new shoots
Rosette
plants. These plants grow from a crown in or
around the gravel bed. Each leaf grows directly from this crown. There are
several types of rosette plants. These include Vallis, a grass like plant,
Amazon swords, Cryptocorynes, Aponatogens and Nympheas or lilies. Vallis,
swords and crypts spread by throwing off runners with young plants growing
along them. When these plants reach a big enough size they can be separated
from the 'mother' plant. Vallis and swords (echinodorus) need to be planted
with the crown above the gravel surface; crypts need to have the crown buried.
Aponatogens and nympheas grow from tubers. The plant can be removed from the
tuber and a new plant will grow again. Some of these plants look good as
individual specimen plants standing out against a background of stemmed plants.
Contrast leaf shapes, sizes and/or colours.
Cryptocoryne
wendetii
Mosses,
ferns and runners. There are only a few aquarium plants
in this group but they are easily available, adaptable and useful. The
commonest are Java fern, Microsorium pterops and Java moss, Vesicularia
dubyana. Another plant, which is often featured by Takashi Amano in his tanks,
is Glossostigma elantoides. This plant produces single leaves along the length
of the runner but with enough light it will produce a thick carpet of cover
over the aquarium gravel. Java moss and java fern can be grown on rocks or
wood. Tie them on with black cotton initially and they will soon attach
themselves by their own roots. Java fern can be grown on gravel provided only
the roots are buried. The rhizome or stem must be above the gravel surface.
Microsorium pterops,
Java fern
Floating
plants. There are a variety of floating plants
available. They can be very useful as nitrate reducers. They tend to be fast
growing and can provide useful shade for fish like Discus that do not appreciate
bright light. They also provide good nest building sites for bubble nesters
like Gouramis. Please, for your own sanity, avoid Duckweed. This is less a
floating plant, more a floating plague.
Light,
CO2, filtration and other accessories. Sufficient
light is an essential for good plant growth. I find that one florescent tube
the length of the tank for each 6" of tank width is sufficient, i.e. two
tubes for a 12" wide tank, 3 for 18" etc. Deeper tanks require more
light. Fitting reflectors to the lamps helps but over 18" deep really
needs mercury vapour lamps. These are cheaper than the metal halides used for
marines but slightly more expensive initially than florescents. They are also
very good over open topped tanks. With an open top you can encourage many
plants to grow up out of the water where some of them will flower, adding
another dimension to your aquarium.
Co2 is plant food.
Plants combine CO2 with other nutrients in the water to produce sugars and
tissues. A by-product of this photosynthesis is oxygen. The oxygen
produced in a planted aquarium is more than sufficient for the fish in the
tank. There are a number of commercial CO2 units available which dissolve the
gas in the aquarium water. The amount of CO2 required varies according to the
plant demand and the hardness of the water. Soft water needs much less than
hard. In very soft water areas, like here in Aberdeen, I get reasonable plant
growth with no additional CO2. Even so the addition of CO2 turns the plant
growth from reasonable to spectacular.
Filtration for a
planted tank should be slower than for a normal tank, no more than 1-1.5 times
the tank volume/hour. External or internal power filters are good. I like to
use a larger filter with the return slowed down. CO2 is easily bubbled off in
gas exchange at the surface so set the filter return about 4" below the
surface. Air driven filters or bubbles are not a good idea.
Substrate/plant
food. Laterite clay is a very useful addition to the substrate as it feeds the
roots of the plants. Use a fairly deep gravel bed, min.2", to allow for
good root growth, particularly for plants like sword plants and crypts.
4-6" is nor too much for some of the larger specimens. Again there are
several commercial substrates available. If you use one then try to get one
that has a whole system built round it. Each manufacturer adds different trace
elements to their substrate and then balances this with other nutrients in
their liquid or tablet plant foods. If you try to mix and match you may find
you are overdosing one element while starving plants of another. Some of these
systems are fairly expensive. While they do give good results it is worth
shopping around.
Under gravel heating
cables. These low power cables are used to encourage a very slow flow of water
and nutrients around the plant roots. Many plants enjoy having their feet warm.
An additional benefit of this slow circulation is that the gravel bed becomes a
very efficient slow biological filter. Some manufacturers make an external
thermostat which controls two heaters, one a cable heater and the other a water
heater. This gives preference to the UG cable with the other heater as back up
if it gets really cold. I achieve the same effect with a heater/stat set at 75F
and a UG cable controlled by an external Stat set at 77F.
Hygrophila
polysperma and Tropica's new ground cover, Hemianthus callitrichoides 'Cuba'
Ease the pots off.
Don't worry too much if you remove any roots growing through the pot, there are
plenty more in the rockwool.
Tease the wool
apart. You'll find that it comes off the roots quite easily. I sometimes use
one of my wife’s knitting needles to get some of the wool away. Rinse them
under the tap to leave...
...bare rooted
plants, a pot, a label and a pile of rockwool. Only the plants go in the tank.
The pot and wool can be kept for potting up cuttings to pass on.
Scoop a small hollow
in the gravel. Using thumb and third finger, hold the plant with the roots in
the hollow, use first and second finger to pull the gravel back over the
roots!?!
For smaller, mat
forming plants like the Hemianthus, you won't really be able to separate them
into individual plants so break the pot into 6-8 sections and remove most of
the wool. The small remaining amount is buried in the gravel for the plants to
grow out of.
You can even sprinkle a little fine gravel over the top of the plant to help secure it.
Using scissors (or
sharp fingernails) make a clean cut just above a pair of leaves.
Remove the bottom of
the stem from the cutting then use the bottom two leaves of the cutting as
anchors to hold it in place until the roots grow. Push them down into the
gravel with your finger tips.
Firm the gravel around the
cutting as shown.