Significant factors affecting the economic sustainability of closed aquaponic systems. Part II: fish and plant growth
Autor: Palm, Harry W.; Bissa K.; Knaus, U. 2014
In:
AACL Bioflux
Bandangabe: 7 Auflage: 3 Ergaenzung: http://www.bioflux.com.ro/aacl
ISBN: 1844-9166 Seite: 162 - 175 Jahr: 2014
Einordung:
Institut: Professur Aquakultur und Sea-Ranching
Abstract: Two identical closed ebb-flow substrate aquaponic systems for warm-water fish were tested for fish and plant productivity. Each system contained 3.7 m3 water, and the relationship of the water volume in the aquaculture tank to the settling basin (sedimenter, clarifier), the biofilter and the hydroponic units was 2.25:1:0.075:0.6 (fish tank:hydroponic unit = 3.75). The comparative batch cultivation of African catfish (Clarias gariepinus) and Nile tilapia (Oreochromis niloticus) at the fish feed input level of 200 g per day resulted in non-significant total growth of 13 kg. The feed conversion ratios (FCR) were 1.0, better values compared with earlier tested closed aquaponic systems. The specific growth ratio was not significantly different (p < 0.05) between C. gariepinus (0.65% d-1 ± 0.25) and O. niloticus (0.71% d-1 ± 0.19). Combined dissolved oxygen (DO) levels in the fish tank, clarifier and sump were significantly different between the two species, with 6.95 mg L-1 (± 0.50) in C. gariepinus and 4.73 mg L-1 (± 1.05) in O. niloticus. Significantly better growth was observed for plants in combination with the Nile tilapia, with 55.89 g (± 49.77) for lettuce and 168.27 g (± 350.88) for cucumber fruits. This is referred to a slightly different light regime and a different fish species cultivation. The available plant nutrients (nitrite, nitrate), as well as the suspended particle load, in both identical systems, also differed, with consequences for system maintenance and substrate biofilter activity. Key Words: African catfish, aquaponics, biomass weight gain, Clarias gariepinus, ebb and flow system, fish to plant combination, Tilapia. Ansprechpartner Weitere Information im WWW
Zur Publikation: Mitarbeiter,
Projekte
Weitere Publikationen im Forschungsteilschwerpunkt
Letzte Änderung des Eintrages:
01.02.2017
|