Tropical tanks cover
a vast area of the hobby, from a basic community tank to a dedicated biotope
for a single species. I'll cover a few of these styles here. All these should
be read in combination with Fishkeeping Basics, which covers setting up
a tank. This section will deal with the differences required for specific
styles of aquarium.
The tanks covered
are
Community | Planted | Woody | River | Rocky
This is very often
the first aquarium for newcomers to the hobby. It contains a mixture of fish
from around the world and is usually fairly easy to maintain. At its most basic
it will have an undergravel filter, powered by an air pump, plastic plants
(live plants won't grow in an undergravel), a heater and a single lamp. When
using a UG filter have 2-3" of gravel over the plate and don't place too
much decor on the gravel as it restricts the water flow. Many fish are suitable
for the community. A pH around neutral will allow you to keep tetras, barbs,
some live-bearers and some cichlids like angels or some dwarf cichlids. Catfish
like Corydorus and many Gouramis will also do well in this kind of set-up. This
kind of tank will initially hold 1" of fish/1 gallon of water. These
should be added slowly, over a few weeks, once the filter has matured. After
it's been running for 6 months you can slowly double this level.
This tank can also
be a community tank, using plants and fish from around the world. Stocking levels
should perhaps be a bit lower than for the community tank and many larger fish
and cichlids are unsuitable as they destroy plants through sheer disturbance or
while setting out territorial boundaries.
Filtration should be
internal or external power filter, turning over the aquarium volume no more
than once/hour. Lighting needs to be more powerful than for a basic community,
at least 20watts/sq.ft. Adding Laterite clay or some other planting medium to
the gravel is a very good idea. A fine gravel bed of between 2-4" gives
the roots something to work in. Carbon Dioxide fertilisation also benefits the
plants.
For
more information see Aquarium plants
Plants are sold
loose or, more often, in leaded bunches or in pots. However they are sold they
should be planted separately. Bunches or pots should be dismantled carefully to
avoid damaging roots, and the plants should be placed so that there is space
between them to allow light to reach all the leaves. Try to avoid straight
lines. Groups of three, five or seven look more natural. The exception to this
is Cryptocorynes. They grow well in bunches but padding, lead weights and
potting material should still be removed before planting. Add any features like
rocks or bogwood first, these provide the focus points for your tank. I like to
take some water out of the tank to avoid flooding, then start with the small
foreground plants. Some Crypts, Glossostigma and/or Echinodorus tennelus, Pygmy
chain sword, make good foreground plants. Move then to the midground plants.
Again there are suitable crypts and sword plants as well as cuttings of some of
the stem plants. By using different size cuttings you can build a rising
terrace of one type of plant from the front to the back of the aquarium.
Diagonals and thirds are useful aids in designing a pleasing picture. Rocks,
wood or feature plants place on thirds or diagonals balance the picture nicely.
The
water for these tanks should generally be acid to
neutral, pH6.5-7.2. If you have hard alkaline water you have the following
options.
·
Choose different fish and plants.
·
Use chemical or other water
conditioners, like reverse osmosis units (expensive) or aquarium softener
resins to alter the water chemistry.
·
Filter your water through aquarium
peat. This will soften and acidify it. It will also turn it brown. Carbon will
remove this colour. This is best done outside the tank, prior to doing water
changes.
·
Use clean rainwater. To help remove
pollutants, this is best filtered through carbon and floss too.
Not, as you
might think, tanks for Toy Story characters but for riverbanks, catfish,
cichlids and vegetarian fish like Silver Dollars and Tinfoil barbs.
These tanks may
contain plants or not, depending on the effect you want and the fish you are
intending to keep. They are generally soft, acid water aquariums but may also
re-create brackish mangrove estuaries. Planted tanks are imitating riverbanks
with overhanging trees, exposed roots and dead wood in the water. In riverbank
aquascapes, the wood is put in 'upside-down' i.e. with the thickest parts at
the top to simulate roots or branches hanging down into the water. The spaces
between the 'roots' can then be filled with plants, which give the impression
of a rising bank, either by trimming them or by creating ascending shelves
supported by the wood. In a taller, part-filled tank some of these 'marginal'
plants can also be encouraged to grow out of the water where they may even
flower. This design is suited to taller tanks so that a reasonable volume of
water is retained for the fish. Additionally moisture-loving plants can be kept
in pots hidden amongst the wood to give a real jungle effect.
Water for brackish
tanks needs to have sea salt added to achieve a specific gravity of about
1.015, about 20grms. /lt. Use lots of wood to give the impression of a tangle
of mangrove roots. The wood is best varnished with a polyurethane varnish to
prevent it acidifying the water.
For tanks without plants,
or plastic plants you have different options for filtration. Under gravel
filters are cheap and easy to install and use medium sized gravel as their
base. External or internal power filters can also be used, but any filter will
need to turn over the tank volume two-three times/hour.
In addition you will
need wood. This should be obtained from your pet store as some woods degrade
and poison water when submerged. Roots of some trees (e.g. European Beech)
which have been waterlogged for a long time can be used and some wood can be
varnished using polyurethane varnish, which does not contain fungicides or
preservatives.
Many of the South
American Tetras and South East Asian barbs and danios relish this crowded, busy
type of decor. Catfish can be kept in the above set-up and
indeed some should be as algae eaters but many of them prefer faster moving
water, as in river tanks. Since many catfish tend to hide during the day you
should try to arrange caves and overhangs in the decor which you can see into.
In fact it is possible, using 'moonlight' tubes or red light to reverse night
and day in these tanks, encouraging the fish to come out when you want to see
them. Some algae growth is to be encouraged for the fish to browse on but
should not be the only food source for the fish. Many 'algae eaters' supplement
their diets with small shrimp and other meaty foods they find among the algae.
Loricariidae and pl*cos (WWW mythology has it that to spell out the full name
of this catfish is death for the fish!) also require Lignin, a supplement they
obtain by grazing on the wood in the tank. For these fish, varnished wood is
NOT a good idea. Most of these fish also prefer a dark, sandy substrate in the
tank.
Cichlids
from South America like soft acid water and wood can be the ideal decor. Some,
like Angel fish, Discus or dwarf cichlids will be quite happy in planted
aquaria but others, like Oscars will soon reduce your careful work to a few
floating scraps and leaves as they dash about, dig pits and generally go about
their macho way of life. Other fish like Silver Dollars love planted tanks-
there's always something to eat -at least for the first few days, and many
larger, more powerful fish like piranha are just too clumsy for plants to
survive. Again, well-secured plastic plants can provide a bit of greenery (or
pinkery or whitery or bluery...) All of these acidophilic, jungle creek fish
will be happy in such a woody tank. A few plants may survive; Java fern, tough
as old boots and not quite so tasty or some large, well rooted sword plants
with their roots protected by larger pebbles may be OK.
These sit between
'woody' and 'rocky' tanks as they are a bit of either or both. Larger filters
and even additional powerheads can be used to create the rapid, well-oxygenated
water for these tanks. This rapid movement and powerful filtration imitates
river rapids and the tangles of dead wood and/or stones found around them. Some
Java fern and Java moss can be attached to the wood to soften it a little.
Plastic plants can be firmly anchored by siliconing them to rocks or wood. The
fish will occupy caves and other shelters among the rocks and wood.
Many sucker-mouthed
catfish and loaches enjoy these conditions, as do some of the West African
fishes like Kribensis.
These tend to be
Cichlid tanks. Central America and the African Rift Valley Lakes are the
classic examples. Many live bearers also come from hard water areas but the
decor is not so exclusively rockwork. Wood and plants are also appropriate for
these.
The rocks in West
Africa and Central America are limestone so this is a good rock to use if you
can get it. To prevent rocks falling and crashing through the glass you can
silicone pieces of slate to the sides and back of the tank to protect the
glass. Build up a maze like structure of tunnels and caves appropriate to the
size of fish you will be keeping. Large rocks, blocking line of sight along the
aquarium will help to define territories and reduce aggression. The water is
usually hard and alkaline. Rift valley fish in particular MUST have this type
of water. pH is about 8.2. This can be achieved by using Rift Valley Salts, and
the use of limestone decor in the tank helps to keep this stable. Even if you
are in a hard water area, make sure it's hard enough. Coral sand is sometimes
advised as a substrate but the fine dust it produces can irritate the gills of
some fish. It must be VERY thoroughly washed
Filtration needs to
be good to cope with the large amount of waste cichlids produce. Under-gravel
may be OK if there is not too much rockwork, which would block it, but external
canister filters, turning over the tank volume two-three times/hour are a
better bet.
Central American
cichlids are BIG and require correspondingly BIG tanks and BIG territories.
Communities of these
fish are generally not practical for the home aquarist although a pair of these
fish in a roomy tank can have a lot of character and be quite impressive.
Watching them spawn and care for their eggs and young is fascinating.
The African Lakes
(Malawi, Tanganyika and Victoria) are different story or rather, three
different stories.
All are community
tanks allowing a variety of cichlids and other fish to be kept together, all
are hard, alkaline water tanks and all, being BIG lakes provide excellent water
quality to their inhabitants. The differences come about due to differences in
the lakes.
Malawi is perhaps
the best known in fishkeeping circles. There are two main tyres of fish, the
Mbuna and the Utaka. Mbuna are rock dwelling, territorial fish while the Utaka
are open water fish and much more sociable. This is a very deep lake with
steeply sloping shores. The water in the middle is so deep that there is very
little life, so the fish are crowded round the shoreline. For Mbuna this makes
territory a very valuable asset and produces aggression to match. The answer is
over-crowding. This may seem a bit strange but it works like this. Males set up
territories and any fish in there has to have a reason. If it's a female of the
same species it had better be there to breed, or else--- Rather than keeping
one lonely male, you put in too many fish so that all this aggro is spread
around and no single fish gets too much. Lots of rockwork and caves give the
fish a chance to rest while somebody else gets it. Limestone is a good rock if
you can get it; it helps maintain the pH and hardness and is in fact the reason
some of these lakes are hard and alkaline in the first place.
Lake Tanganyika is
big too but it's shallower so the fish have more room to spread out, a variety
of habitats. Given that each fish is used to having an exclusive territory they
are not at all neighbourly and will not tolerate other fish in their space. You
might get away with a rock dwelling pair and a pair of shell dwellers in one
tank. Less rockwork, a sandy bottom, some escargot snail shells and even some
Vallis plants won't go amiss here. Some of the fish are rock-dwellers, some are
shell dwellers and some are open spawning. Over-crowding is not a good idea
here. Fewer fish produces a much happier tank.
Lake Victoria is
somewhere in the middle. The fish aren't so aggressive but territory still
centres round rock piles. Stocking levels can be around standard tropical:
10sq.ins. /1" of fish.
Filtration and water
changes need to match the tank population; Malawi needs lots of filter power
and regular water changes, Tanganyika needs a lot less as it has a low stock
level and Victoria needs good but not over the top.
One other thing. The
variety of fish in these lakes is the evolutionary result of a few species
being trapped when the lakes were formed. These diversified to fill all the
available space, but closely related species can still inter-breed. Avoid this
at all costs; choose diverse species from the many on offer.