Question

In biofloc system of culture, what is more important ?

• A. C : P ratio
• B. N : P ratio
• C. C : N ratio
• D. C : K ratio

Hint:

The success of biofloc technology depends on heterotrophic ammonia assimilation, which requires maintaining a high Carbon-to-Nitrogen (C : N) ratio of approximately 15:1.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Biofloc Technology (BFT) is an environmentally friendly aquaculture system based on in-situ microorganism production.
It relies on maintaining a balance of carbon and nitrogen to promote the growth of heterotrophic bacteria, which convert toxic nitrogenous wastes (like ammonia) into useful microbial protein.
Detailed Explanation:
In a biofloc system, the Carbon-to-Nitrogen (C : N) ratio is the key parameter for water quality and system stability.
- Fish excrete nitrogenous wastes (mostly ammonia) into the water.
- To encourage heterotrophic bacteria to assimilate this inorganic nitrogen into microbial biomass (bacterial floc), carbon must be added to the system (often using organic carbon sources like molasses, starch, or wheat flour).
- Maintaining a high C : N ratio (typically 12:1 to 20:1) ensures that heterotrophic bacteria have enough carbon to process the available nitrogen, keeping ammonia concentrations near zero and producing a nutritious natural food source (floc) for the cultured fish or shrimp.
The other nutrient ratios (C:P, N:P, C:K) are not the primary drivers of this biological waste-conversion process.

Step 2: Final Answer:
In a biofloc culture system, the C : N ratio is the most important parameter.