Black
water pools, creeks and rivers originate in the rain forest areas of the world. The term “Black
Water comes from the staining process of the
water as it passes through decaying vegetation and roots; discoloring the
water to a bronze tea color. These waters are very acidic and soft, the
hardness in some areas is negligible.
In South America one of the most famous regions is the Rio Negro which is the second largest tributary of the Amazon, at least 450 miles long by boat but impassable after that due to the number of sandbanks etc. As the tributaries flood many of the ponds and streams are formed; indeed during the flooding season as lot of the
fish species will use this as their breeding season, depositing their eggs among the sunken roots and
plant life. In black
Water habitats the
substrate is typically leaf litter over a base of clay or sand. Decaying
wood and
plant matter is common especially in flooded forest areas. As the floods occur many of the terrestrial
plants become submerged but do not suffer any ill side effects as a result.
The
pH of the
water can be as low as 4.5 and the maximum is usually around 6.5.
Temperature of the
water is on the high side (27 – 30 deg C), and as mentioned earlier the
hardness of the
water will be as low as 0-4 DH. Recreating these conditions in a
biotope can be difficult but not impossible.
Setting up the tank
Fine
gravel or sand should be used for the
substrate with pieces of bog
wood either laid on the
substrate or mounted horizontally to give the impression of submerged roots. For a realistic effect the
lighting should be subdued and a low
water flow inside the
tank. Peat run inside the
filtration system will help to soften the
water and reduce the
pH. Always test the
KH on a regular basis, if it drops too low you run the risk of a
PH crash. Keeping it above 3 DH will prevent this from happening.
Plants for the tank
For the
background Cabomba
planted in groups is ideal, this is normally used in brightly lit
tanks but will grow with subdued
lighting. Sword
plants (Echinodorus) are perfectly happy with low
lighting and are found in Black
Water areas naturally. Use the larger species at the rear of the
tank but
plant some of the dwarf species in the fore ground to give a good effect. Vallisneria looks great for the mid to back of the
tank set in groups. For a floating species, use the tropical hornwort. This
plant can even be used as a bunch
plant at the rear of the
tank alongside the cabomba.
Fish for the tank
Discus and
Angelfish are the two top candidates for this
biotope; the golden rule is not to place both species in the
tank together. Decide which of the two you wish to add as
Angelfish can easily pass diseases onto the
discus even though they are not affected themselves.
Corydoras make great
substrate cleaners; if adding them it would be better to use a sand
substrate as they can damage their barbells on
gravel.
Most of the
tetra species are ideal; in my own
biotope I use a shoal of
cardinal tetras with
discus, the effect really works.
Loricarids (armoured
catfish) will also do a cleaning job on the
biotope;
Ancistrus are well renowned as
aquarium glass cleaners.
Dwarf cichlids, of which there are many to choose from, make for interesting
tank viewing, especially if you are lucky enough to get a pair.
Sources of information
www.mongabay.com,
www.wikipedia.orgSouth American Blackwater Stream
has been viewed times since June 30, 2009.