A large number of factors affects in the rise and fall of microalgae populations. One of the most important factors is nutrients specially nitrogen and phosphorus. One of the most important freshwater green algae is Chlorococcum , which belongs to family of Chlorococcaceae and P=12%, N=15%) and 0.1, 0.4, 0.8 kg/m 3 of cattle manure (C=25%, P=3%, N=11%); effects of inorganic algal media including BBM (Bold Basal’s Medium), BBM+soil extract and BBM with 5, 10, 15 and 25mg/l of Na 2 HPO 4 on green algae, Chlorococcum sp. culture were examined in randomized complete block design. Results shown this species could be able to growth on chicken and cattle manures, but the mean maximum specific growth rate (0.054 day -1 ), algal dry biomass (0.644 mgL -1 ), chlorophyll a (9.42 mgL -1 ) and minimum doubling time of population (12.63 days) were obtained from Chlorococcum . Comparable results between inorganic media indicated that BBM+ soil extract had suitable performance with highest algal density (11.5 × 10 6 cells/ml), dry weight (0.79 mg/ml), and specific growth rate(0.101 day -1 ) . To comparison organic and inorganic algal culture media for Chlorococcum a experiment between the most suitable examined media (BBM, BBM+soil extract, 0.8 kg/m 3 chicken manure, 0.8 kg/m 3 cattle manure and their mixture at 1:1:1:1 ratio) was conducted. The results showed that the highest algal density (11.6 × 10 6 cells/ml), dry biomass (0.81 mg/ml), specific growth rate (0.13 day -1 ) and chlorophyll a (9.42 mgL -1 ), were obtained with those Chlorococcum grown on BBM+soil extract. This microalgae was easily cultured using organic and inorganic media and could also benefit from its biomass in different aquaculture purposes as well as other industries. Keywords Green algae Chlorococcum , Algal culture, Algal medium, Algal growth and biomass, Chlorophyll a , Soil extract.
