questions: asked about biofloc fish farming and raft culture 
 answers: biofloc culture- harmful substances are converted into useful fish feed using probiotic and other substances,
only for summer season. higher c:n ratio is maintain by adding carbohydrate sources.
oxygen is provided on daily basis and regular check of ammonia, nitrite, nitrate, oxygen level, ph level and h2s gas 
minimun requirement of stabdard fish feed 

raft cu8lture- maninly use for mussel farming 
iron or wooden or pvc fram are arranged forming a standard square or retangular floated by using empty drum 
rope are tied to the frames the other end of the ropes are remain submerged inside the water by using weight 
 for such practices please visit your district fisheries department and participation in traing is must