Sandy rift in the middle reaches of the Kalchik river. Ukraine

_th place in Biotope Aquarium Design Contest 2020

Volume: 250L
Dimensions: 100*50*50
List of fishes: Alburnus alburnus
Gobio gobio
Pseudorasbora parva
Rhodeus amarus
Rutilus rutilus
List of plants: Phragmites australis
Potamogeton natans
Ceratophyllum demersum
Description of decorations: Oak driftwood of company resembling those flooded in the river
Hagen primer 1-2mm
Description of equipment: External filter, Eheim Experience 350, 1050 l / h.
Circulating flow pump, Aqua Nova NWM-2000, 2000 l / h.
Backlight – Lamp Ptero Ray Mini 25, 9 W.
Upper (main) – Lamp Ptero Ray 5950 / 90-100, 63 W
Water parameters: 24С
рН- 8,0
gH- 27
kH -10
PO4 -0
Additional info: weekly change of 30% water


Description of the area surrounding the biotope: Kalchik is a river flowing through the territory of the Donetsk region of Ukraine. Right tributary of the Kalmius river. Kalka is a small rivulet, a tributary of the Kalchik, flows between the villages of Katerinovka and Maloyanisol in the Nikolsky district of the Donetsk region
The source of Kalchik is located in the village of Kalchinovka, on the border of Donetsk and Zaporozhye regions. Kalchik flows into Kalmius 6 kilometers from its mouth in the city of Mariupol, on the northern outskirts of the Azovstal plant. It has a tributary Maliy Kalchik. The Starokrymskoye reservoir is located on the river. The river is 88 km long. The drainage area of Kalchik is 1263 km². Water consumption is from 3.0 to 30 m³ / sec [1]. On the watershed between the rivers Berda and Kalchik there is the Kamennyi Mogily reserve, a branch of the Ukrainian Steppe Reserve.
Description of the underwater landscape of the biotope: A complex complex of aquatic and wetland vegetation and no less diverse fauna develops in the Kalchik River and its tributaries. The organisms that live in the river have adapted to their habitat. The bottom of the river is silty with sandy shoals, consisting of granite chips. The main ecological groups of organisms in water bodies are plankton and benthos in the form of phyto – and zoobenthos. The hydrofauna is represented by freshwater fauna. Of the higher aquatic plants, the Kalchik River is characterized by reed, cattail, horn-leaved plants, and duckweed near the banks.
Description of the parameters of the habitat: 26C – summer
In winter – freeze-up
pH 7.8-8.0
gH- 27 -30
TDS- 1500
List of fishes and invertebrates occurring in the nature biotope: Neogobius gymnotrachelus
Leucaspius delineatus
Squalius cephalus
Carassius gibelio
Cyprinus carpio
Scardinius erythrophthalmus
Gasterosteus aculeatus
Tinca tinca
Abramis brama
Perca fluviatilis
Rutilus rutilus
Sander lucioperca
Alburnus alburnus
Аlburnus leobergi
Сobitis tanaitica
Esox lucius
Idus idus
Alburnus alburnus
Gobio gobio
Pseudorasbora parva
Rhodeus amarus
Rutilus rutilus
List of plants found in the nature biotope: Stratiotes aloides
Phragmites australis
Butomus umbellatus L.
Ceratophyllum demersum
Typha minima
Potamogeton crispus
Potamogeton natans
Threats to the ecology: In the upper and middle reaches of Kalchik, it is polluted by salts washed away from agricultural territories, in the lower reaches of the Mariupol household wastewater. An increased content of oil products and non-volatile phenols is observed in water [1].

Water salinity increases from source to mouth. Near the mouth, mineralization reaches 2.5 g / l
Sources of information:

Comments of the members of the jury of Biotope Aquarium Design Contest 2020