Preliminary communication

Improvement of water quality on carp fish farms

Ljubica Debljak ; Sveučilište u Zagrebu, Agronomski fakultet, Svetošimunska 25, 10 000 Zagreb
Krešimir Fašaić ; Centar za ribarstvo, Kneza Mislava 2/V, 10 000 Zagreb
Željko Bebek ; Direktor ribnjaka Donji Miholjac, Donji Miholjac
Zdenek Adamek ; Istraživački institut za ribarstvo i hidrobiologiju, Vodnjani, Češka republika
Darko Slačanac ; Ribnjačarstvo Donji Miholjac, Donji Miholjac

Abstract

Investigations on the effect of potassium salts (10 mg L-1 1), hydratized lime (10 mg L-1 ) and copper sulphate (0.2 mg L-1) on the biochemical consumption of oxygen (BPK 24 h), were carried out on the fish farm D. Miholjac, in fish ponds 1a (16 ha), 1b (15 ha) and 1c (15 ha). Two year old carp fry (young) were cultured with a stocking density of 12 500 ind/ha-1 (625 kg/ha-1 ), 13 300 ind/ha-1 (560 kg/ha-1) and 12 000 ind/ha-1 (780 kg/ha-1), respectively.
The doses given of all applied chemicals decreased the BPK 24h, but diffe¬rently (Table 4.). The individual doses of potassium salts used decreased the biochemical consumption of oxygen during 24 hours from 0.27 to 2.5 mg L-1 (9-73%), hydratized lime from 0-1.29 mg L-1 (0-44%) and copper sulphate from 0 to 1.97 mg L-1 (0-44%). Only the application of potassium salt was statistically justified (P < 0.05). The decrease of BPK 24 h was more expressed in the period when the oxygen concentration in the water was low.

Keywords

carp pond; water quality

Hrčak ID:

77054

URI

https://hrcak.srce.hr/77054

Publication date:

23.9.1993.

Article data in other languages: croatian

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