Igarapé do Daracua, shallow blackwater stream of Rio Negro, Brazil

_th place in Biotope Aquarium Design Contest 2020

Volume: 140 Litres
Dimensions: 120×30×48
List of fishes: Hemigrammus bleheri
Paracheirodon axelrodi
Aphyocharax anisitsi
List of plants: Not such aquatic plants seen in the habitat
Description of decorations: The driftwoods are collected from nature, which is similar to the woods found in the shallow stream, and also to give the natural feel, the small twigs and branches are added for a bit more detailing. The Substrate is made of a mixture of natural river base sand, and natural sand. Leafs are added on weekly basis to give it a natural look of leaves fallen from the trees, and also to create a layer over the substrate as a second substrate. New leaves are added to imitate natural layers, seen in the habitat.
Description of equipment: Filter – internal dual sponge filter
Light- phillips led 24 watt cool daylight, 2 spotlights of 8 watt
Flow- 800lph powerhead to provide the minimum flow seen in those streams
Water parameters: Temperature is 28°c
Ph is 6
Additional info: Water change monthly once 20%

INFORMATION ABOUT BIOTOPE:

Description of the area surrounding the biotope: Igarapé do Daracua is actually representative of a wide variety of shallow, forest streams, black water habitats, that is found throughout the amazon and its tributaries but specially the Rio Negro in Brazil, not very far from barcelos, this small forest streams are filled with branches and leaves, that are fallen off the tree.
Description of the underwater landscape of the biotope: The small river passes through a forest, it carries sands with it, so the bottom is sand, and there is a lot of driftwoods found at the bottom, the branches fall from the trees and the leaves forms a layer over the sand substrate.
The dense layer of leaves, filled with biofilm, provides food for the fishes, the leaf also provides shelter for the smaller fishes and they look for small insects for their food.
The leaf layer also has a lot of organic particles. The sunrays through the trees creates a nice shade at the bottom.
The water is moderately transparent, a bit tanned, tea colored, the sunrays passes through the trees around the stream, and when falls on the stream creates a nice shade at the bottom.
Description of the parameters of the habitat: Water is a bit tea colored, a bit yellowish, the temperature stays around 28-30 degree Celsius, sometimes in summer it increses to 32 degree celcisus. Ph can be as low as 4.5 and can range upto 6.5, depending on the both area and season.
List of fishes and invertebrates occurring in the nature biotope: Hemigrammus bleheri,
Nanostomus eques,
Dicrossus filamentosus,
Acarichthys heckelii,
Crenicichla marmorata,
Heros notatus,
Poecilocharax weitzmani
Mesonauta festivus,
Paracheirodon axelrodi,
Aphyocharax anisitsi,
List of plants found in the nature biotope: Not such aquatic plants seen
Sources of information: