Biofloc Technology: A Simple, Green Way to Farm Fish and Shrimp

With seafood lovers wanting more and wild fish stocks dropping—over 33% are overfished, says Fish Vigyan—old-school fish farming can mess up nature with tons of waste and water. Enter Biofloc Technology (BFT), a smart, planet-friendly fix that uses tiny microbes to clean water and double as fish food in a setup that barely wastes a drop. Wondering how Biofloc makes farming fish or shrimp easier and greener? This blog explains it in plain words—covering how it runs, its perks, a few hurdles, easy setup tricks, real-life success stories, and why it’s shaking up affordable aquaculture.

Note: This article draws on the expertise and insights of Aftab Alam, Consultant and Lead Independent Researcher at Fish Vigyan.

What Is Biofloc Technology?

Biofloc Technology (BFT) is a sustainable aquaculture method that raises fish or shrimp using bacteria to manage waste and create natural food. In tanks or ponds, waste turns into “flocs”—clumps of microbes, algae, and organic matter—that the fish or shrimp eat. Unlike traditional systems that flush out water, Biofloc reuses it with minimal replacement (In Situ water treatment), saving resources while boosting production. It mimics nature by recycling waste into a valuable resource, making it both eco-friendly and efficient.

The goal? Grow more seafood sustainably. As per Fish Vigyan, aquaculture must expand massively by 2050 to feed the world, and Biofloc is key. It shines in water-scarce or land-limited areas, producing organic fish or shrimp without polluting rivers or oceans—a win for farmers and the planet.

How Does Biofloc Technology Work?

Biofloc blends biology and farming practically. Here’s the process step-by-step:

1. The Tank or Pond

• Role: Fish or shrimp live in tanks (1,000 to 100,000+ liters), often made of concrete, plastic, or tarpaulin, or in tarpaulin-lined ponds.

• Details: Tarpaulin-lined ponds are affordable and common, with sizes tailored to farm needs. Tanks can be indoors or outdoors, depending on climate and space.

2. Adding Fish or Shrimp

• Role: Species like tilapia or shrimp are stocked densely—up to 20-40 kilograms per cubic meter, as per Fish Vigyan.

• Details: These species thrive by eating flocs, chosen based on local markets and resilience in high-density setups.

3. Feeding and Waste Production

• Role: Farmers provide feed, and waste (droppings, uneaten food) releases ammonia into the water.

• Details: Feed use drops 20-30% since flocs add nutrition, as per Fish Vigyan, cutting costs and waste.

4. Aeration System

• Role: Pumps or paddlewheels add oxygen and mix water, supporting fish and microbes.

• Details: Oxygen stays at 5-7 milligrams per liter (ppm), vital for growth, as per Fish Vigyan. Insufficient oxygen harms fish and slows floc formation.

5. Microbial Action (Biofloc Formation)

• Role: Bacteria convert ammonia into protein-rich flocs, driven by a carbon-to-nitrogen (C:N) ratio of 10:1 or higher.

• Details: Carbon sources like sugar syrup or molasses spark this, as per Fish Vigyan, creating a natural feed cycle.

6. Water Quality Control

• Role: Flocs help maintain ammonia at safe levels, ideally at 0 milligrams per liter (ppm), though brief spikes below 0.25 mg/L (ppm) total ammonia may be tolerable in new or cycling tanks, particularly at lower pH levels, according to Fish Vigyan.

• Details: Ammonia becomes more toxic as the pH increases from 6.5 to 8 and the temperature rises between 25 and 30°C. To prevent stress, nitrite levels should remain at 0 mg/L (ppm), or as close to undetectable as possible, since levels above 0.1 mg/L can be harmful, particularly to sensitive fish species. Daily water changes may be adjusted based on need, but larger changes, such as 10-25% of the total volume, are often recommended to effectively dilute nitrite spikes, especially during tank cycling or after disruptions.

7. Harvesting

• Role: Fish or shrimp (e.g., tilapia at 200-300 grams) are harvested after 3-6 months.

• Details: Yields hit 20-40 tons per hectare, as per Fish Vigyan, with nets making collection easy before restarting the cycle.

Key Parameters in Biofloc Farming

Managing water quality and system balance is crucial. Here’s what farmers track, per Fish Vigyan:

• Dissolved Oxygen (DO): Kept at 5-7 mg/L (ppm) for fish health and floc growth. Low DO risks fish stress or death.

• Temperature: 25-30°C suits tropical species, affecting growth and ammonia toxicity.

• pH: 6.5-8 range prevents ammonia from turning deadly; too high or low stresses fish.

• Ammonia (TAN): Ideal is 0 mg/L (ppm), but below 0.25 mg/L (ppm) is safe. High pH or heat makes it toxic faster.

• Nitrite: Close to 0 or below 0.1 mg/L (ppm) avoids poisoning fish in dense setups.

• Nitrate: Managing nitrate levels below 50-100 mg/L (ppm) to prevent long-term stress and water quality decline, requiring occasional dilution.

• TSS: Controlling Total Suspended Solids (TSS) between 200-500 mg/L to balance floc availability and water clarity, avoiding gill irritation. TSS includes both settleable and non-settleable solids

• Settleable Solids: It is a portion of Total Suspended Solids (TSS) that settle out within 30-60 minutes, typically range from 5-25 mL/L in an Imhoff cone for a TSS of 200-500 mg/L in Biofloc systems, averaging around 10 mL/L, depending on floc type, settling time, and characteristics.

• Alkalinity: Keeping alkalinity at 100-150 mg/L (as CaCO₃) to stabilize pH and support microbial activity.

• Salinity: Monitoring salinity at 0-35 ppt, depending on species (e.g., freshwater fish vs. shrimp), to maintain osmotic balance.

• Turbidity: Ensuring turbidity levels of 20-50 NTU to indicate healthy floc development without compromising visibility or oxygen levels.

• C:N Ratio: 10:1 to 15:1 ensures bacteria thrive, forming flocs efficiently.

• Stocking Density: 20-40 kg/m³ maximizes yield without overcrowding.

• Feed Conversion Ratio (FCR): Improved by 20-30%, meaning less feed for more fish.

Farmers use test kits to monitor these daily, keeping the system productive and fish healthy.

Setting Up a Biofloc System: A Farmer’s Guide

Starting a Biofloc farm takes planning. Here’s a practical guide from Fish Vigyan:

Choosing a Location

Find a spot with water and power access. No rivers or lakes needed—Biofloc’s low-water use fits dry areas. Flat land simplifies tank or pond setup.

Building Tanks or Ponds

Small farms start with 1,000-liter plastic or tarpaulin tanks. Larger ones use concrete or tarpaulin-lined ponds up to 100,000 liters. Dig a hole, line it with tarpaulin, and fill it—cheap and quick.

Installing Aeration

Aeration keeps oxygen at 5-7 mg/L (ppm), using pumps or paddlewheels (100 watts per 10,000 liters, as per Fish Vigyan). Solar panels help where power’s shaky.

Adding Bacteria and Carbon

Kickstart flocs with carbon sources like sugar syrup, molasses, or wheat flour. A 10:1 C:N ratio gets bacteria going, as per Fish Vigyan.

Stocking Fish or Shrimp

Add tilapia, shrimp, or carp at 20-40 kg/m³, based on market demand. Start small to test the system, then scale up.

Monitoring Water Quality

Use kits to check DO, pH, ammonia, and nitrite daily. Adjust carbon or water if ammonia nears 0.25 mg/L (ppm). Steady care keeps fish growing.

In weeks, a small setup can produce fish or shrimp, scalable with experience.

Why Biofloc Technology Is Gaining Ground? – Insights from FishVigyan.com

Discover why Biofloc Technology (BFT) is transforming fish farming, as explained by the experts at FishVigyan.com:

1. Efficient Water Use:

Utilizes minimal water exchange (just 1-5% daily or none at all), a stark contrast to traditional methods needing constant water flow, perfect for drought-prone areas.

2. Eco-Friendly Approach:

Harnesses microbial flocs to recycle nutrients, cutting down waste pollution and promoting sustainable aquaculture practices.

3. Budget-Friendly Farming:

Slashes costs by reducing water needs, feed expenses (with a 20-30% better FCR), and manpower, offering affordable solutions for fish farmers.

4. Boosted Yields:

Enables high-density stocking (20-40 kg/m³), increasing fish and shrimp production per space, ideal for profit-driven operations.

5. Natural Nutrition:

Provides protein-packed bioflocs (20-40% protein) as a free feed supplement, enhancing growth rates for species like shrimp and tilapia.

6. Superior Water Quality:

Manages harmful ammonia (0-0.25 mg/L), nitrite (<0.1 mg/L), and nitrate via microbial action, ensuring a healthier aquatic environment.

7. Versatile Applications:

Adapts to various species and setups—indoor tanks, outdoor ponds, or urban farms—making it a flexible choice for all farmers.

8. Weather Independence:

Thrives with limited external water, offering resilience in changing climates or regions with scarce freshwater resources.

9. Healthier Stock:

Strengthens fish immunity and curbs disease by fostering a balanced microbial system, reducing risks compared to conventional ponds.

10. Growing Market Appeal:

Caters to rising demand for sustainably sourced seafood, positioning farmers to succeed in eco-conscious markets.

11. Tech-Supported Simplicity:

Leverages user-friendly tools like turbidity meters and Imhoff cones, backed by research, to streamline adoption for beginners and pros alike.

At FishVigyan.com, we see these advantages fueling BFT’s rise as a game-changing, sustainable, and efficient aquaculture method for modern fish farming.

Which Species Suit Biofloc?

Biofloc technology (BFT) is particularly effective for cultivating certain aquatic species that thrive in high-density, microbial-rich environments. Here are some species commonly raised using biofloc systems:

1. Shrimp

• Pacific White Shrimp (Litopenaeus vannamei): This species is the most popular choice for biofloc systems due to its adaptability to varying water conditions and its ability to consume bioflocs as a supplementary food source.

• Black Tiger Shrimp (Penaeus monodon): While suitable, it is less frequently used compared to L. vannamei.

2. Tilapia

• Nile Tilapia (Oreochromis niloticus): Tilapia is highly adaptable to biofloc systems and can efficiently convert bioflocs into protein, making it a preferred option for BFT.

3. Catfish

• Channel Catfish (Ictalurus punctatus): Catfish can be raised in biofloc systems, though they may require more intensive management compared to shrimp or tilapia.

• African Catfish (Clarias gariepinus): Known for its resilience and rapid growth, this species is also suitable for biofloc systems.

4. Carp

• Common Carp (Cyprinus carpio): Carp can be cultured in biofloc systems, though they are less commonly used than shrimp and tilapia.

• Rohu (Labeo rohita): A widely cultivated species in South Asia that can adapt well to biofloc systems.

5. Other Species

• Barramundi (Lates calcarifer): This species can be cultured in biofloc systems but requires careful monitoring of water quality.

• Mullet (Mugil spp.): Mullet can also be raised in biofloc systems, especially in polyculture setups.

Key Considerations:

• High Stocking Density Tolerance: Species that can thrive in crowded environments are better suited for biofloc systems.

• Omnivorous or Detritivorous Feeding Habits: Species that can consume bioflocs directly or benefit from the microbial protein in the system are ideal.

• Hardiness: Species resistant to diseases and capable of tolerating fluctuating water conditions perform better in biofloc systems.

Less Suitable Species:

• High Oxygen Demand: Species requiring very high dissolved oxygen levels may not be ideal, as microbial activity in biofloc systems can reduce oxygen availability.

• Carnivorous Species: These may not benefit as much from bioflocs and often require costlier feed, making them less suitable for BFT.

In summary, species like Pacific White Shrimp, Nile Tilapia, and certain catfish are among the best choices for biofloc technology due to their adaptability, feeding habits, and ability to thrive in high-density environments.

Benefits of Biofloc Technology Explored

Water Conservation

Biofloc cuts water use by 90%, as per Fish Vigyan—perfect for dry regions like Andhra Pradesh. A tank needs just a bucket daily per kg of fish.

Cleaner Ecosystems

Waste turns into food, not pollution. Fish Vigyan predicts a 50% drop in aquaculture’s eco-footprint by 2030, sparing wild fish habitats.

Budget-Friendly

Less feed and water save 20-40% on costs, as per Fish Vigyan. Feed, the biggest expense, drops significantly with flocs.

Big Yields

20-40 tons per hectare beats ponds’ 2-4 tons, thanks to flocs and density, ideal for small land areas.

Weather Resilience

Controlled setups handle rain or drought, dubbed “climate-strong” by Fish Vigyan.

Food Supply

Biofloc could provide 30% of farmed seafood by 2030, as per Fish Vigyan, feeding millions affordably.

Challenges of Biofloc Technology

Biofloc isn’t perfect:

1. Initial Investment

Tanks, aerators, and liners cost ₹1.5 lakhs (3-4 10,000-liter tanks) to ₹15 lakhs (35-40 tanks), as per Fish Vigyan. Small farmers may need loans.

2. Skill Needs

Farmers must master C:N ratios, flocs, and aeration. Fish Vigyan notes training gaps slow adoption.

3. Power Use

Aerators need 100 watts per 10,000-liter tank, as per Fish Vigyan—outages can disrupt oxygen.

4. Floc Balance

Excess flocs clog water or stress fish, requiring regular removal.

Troubleshooting Common Biofloc Issues

Problems happen—here’s how to fix them, per Fish Vigyan:

• High Ammonia (>0.25 mg/L): Add carbon (e.g., sugar syrup) to boost bacteria, or swap 5% water.

• Low Oxygen (<5 mg/L): Check aerators for clogs or power issues; add a backup pump.

• Floc Overload: Scoop out excess with nets if water gets murky or fish gasp.

• pH Swings: Add lime to raise pH or reduce carbon if too high, keeping it 6.5-8.

Daily checks with test kits catch issues early, saving crops.

Economic Feasibility: Does Biofloc Pay Off?

Biofloc’s costs and profits vary:

• Setup: ₹1.5 lakhs (small, 3-4 tanks of 10 cubic meter each) to ₹15 lakhs (large, 35-40 tanks), as per Fish Vigyan.

• Running Costs: Feed (reduced 30%), power (₹5,00-10,000/month for large setups), and water (minimal).

• Revenue: Tilapia at ₹150/kg or shrimp at ₹400/kg yields ₹3-8 lakhs/ha annually, depending on density (20-40 tons/ha).

• Break-Even: Small farms recover in 1-2 years; large ones in 2-3, as per Fish Vigyan.

For low-cost fish like carp (₹150-200/kg), Biofloc beats RAS, making it profitable where premium fish don’t sell.

Profitable for Low-Cost Fish Farming (Unlike RAS)

Biofloc shines for affordable fish:

• Lower Costs: INR 1.5-15 lakhs vs. RAS’s INR 40 lakhs to 1 Crore, as per Fish Vigyan.

• Simple Tech: Uses basic aeration and flocs, not RAS’s complex filters.

• Market Fit: Carp at INR 150-200/kg thrives in India, unlike RAS, as per Fish Vigyan.

RAS suits salmon; Biofloc wins for budget species.

Biofloc Globally: Real-World Cases

• India: Andhra Pradesh shrimp farms hit 30 tons/ha, as per Fish Vigyan, earning ₹10 lakhs/ha yearly.

• Vietnam: Biofloc shrimp make 20% of exports, as per Fish Vigyan, boosting rural jobs.

• Mexico: Tilapia farms save 85% water in arid zones, feeding local markets.

• Thailand: Catfish yields rise 50%, cutting feed costs.

• Indonesia: Carp farms use 90% less water, as per Fish Vigyan, thriving in small spaces.

The Future of Biofloc Technology

Better Tools

Sensors for flocs and oxygen cut risks by 25%, as per Fish Vigyan.

Solar Shift

Solar aerators in India slashed costs 30% in 2023—clean and cheap.

Small-Scale Growth

Tarpaulin kits aim for small farmers by 2026.

Mega Farms

Trials target 50 tons/ha, as per Fish Vigyan.

Health Gains

Healthy bacteria (probiotics) in flocs boost growth 15%, as per Fish Vigyan.

Biofloc vs. RAS

Feature Biofloc RAS

Water Use 1-5% daily 1-10% daily

Setup cost ₹1.5-15 lakhs ₹40-100 lakhs

Power 100W/10,000L 40-60% of costs

Output 20-40 tons/ha 20-40 tons/ha

Low-Cost FishProfitable Not profitable

Why Biofloc Matters

Biofloc delivers fresh seafood, a cleaner planet, and food security. As wild fish fade, it meets needs sustainably, impacting your plate and global hunger.

Final Thoughts

Biofloc turns waste into wealth—saving water, cutting costs, and growing fish affordably. It needs skills and power but beats RAS for low-cost farming. As per Fish Vigyan, it’s a cornerstone of eco-friendly aquaculture. Your next meal might be Biofloc-grown!

What do you think? Share below!

Tags: Biofloc Technology, Sustainable Aquaculture, Low-Water Farming, Organic Fish Farming, Tilapia in Biofloc, Shrimp Farming