Biofloc Aquaculture System- Basic

Discover what biofloc is, a protein-rich live feed from a microbial mix. It forms from unused feed and excreta, includes bacteria, protozoa, algae, and minerals, with 25–50% protein.

Biofloc uses photosynthesis in the Hyflux system to convert uneaten feed and nutrients into food, breaking down ammonia and nitrate. It supports diatoms, fungi, protozoans, plankton, feeding fish and shrimp.

Maintain water quality and dissolved oxygen; keep temperature 25–32 degrees, and ensure steady carbon sources (molasses, jaggery, sugar, tapioca, rice bran) with proper loading and mixing, to promote floc development.

Learn to maintain floc in buffalo fish farming with biofloc system by keeping density 30–40 per thousand and replacing 15–30 percent of water, adding probiotic with molasses to manage ammonia.

Explore the role of important bacteria in the biofloc system, including catastrophic, hypertrophic, and atrophic bacteria, and how bacterial biomass reduces ammonia by processing organic and nitrogen compounds.

Biofloc system bacteria regulate water quality by ammonia-oxidizing bacteria converting ammonia to nitrite and nitrite-oxidizing bacteria converting nitrite to nitrate. External carbon sources boost microbial biomass, supporting phytoplankton and zooplankton.

Understand the biofloc tank concept and how to set up a water tank with tarpaulin or cement. Recognize how LifeLock enables dense aquaculture with minimal investment and better profitability.

Tarpaulin tanks are economical, quick to set up, and portable but puncture-prone and less durable; cement tanks are strong, long-lasting (30–50 years), and offer temperature stability at higher costs.

Calculate tank volume and water capacity using cylindrical formulas with radius and height, and convert between cubic feet and liters, plus rectangular tank calculations with length, width, and water-filled height.

Round biofloc tanks minimize surface area, stabilize water temperature, reduce heat loss, and prevent corners where microbes hide; they distribute hydrostatic pressure evenly for easier cleaning and stronger structure.

Identify and gather essential materials for building a biofloc tank, including bricks, cement, waterproofing, tarpaulin, wire mesh, pipes, pumps, valves, and temperature monitoring equipment.

Set up a tarpaulin tank for a biofloc system by forming a center-point drain with a sand slope, a circular brick boundary, and installed irrigation pump, ensuring tarpaulin cleanliness.

Set up a multi-tank biofloc aquaculture system with a central drainage, water inlet pipe, sludge exit, and a spare tank, ensuring every tank bottom slopes toward the center drain.

Learn how pH, the potential of hydrogen, acts as a key water quality parameter in biofloc systems, with a neutral 7 and an optimal fish-friendly range around 6.5 to 7.5.

Optimize pH in biofloc systems to safeguard fish health: low pH (<7) increases mucus and stress; high pH boosts ammonia toxicity and damages eyes and skin; monitor temperature.

Explore how pH affects fish growth and reproduction in biofloc systems, highlighting ranges from 4–5 to 6–7 and the need to set and maintain the right pH throughout the cycle.

Adjust pH in a biofloc system with calcium carbonate or dolomite to raise pH when below six, targeting 6.5–7.5 (6–8 tolerance); use one tablespoon per 1000 liters and test batches.

Develop reliable pH testing in a biofloc system by using dolomite or calcium carbonate to reach required levels and verifying results with a digital meter.

Discover total dissolved solids, how rainfall dissolves minerals from rocks and soil to shape water taste, and how calcium, magnesium, and sodium determine hardness and potability.

Explore tds in aquaculture by linking total dissolved solids to dissolved ions like calcium, magnesium, potassium, sodium, and chloride, and apply salinity awareness to freshwater versus saline classifications.

maintain target TDS in a biofloc system by balancing freshwater (200-300 ppm) with sea salt and sodium chloride, adjusted per species (200-800 ppm) to support water clarity, photosynthesis, and temperature.

Learn to maintain total dissolved solids in a biofloc system by adjusting sea salt to reach salinity around 1200–1800 ppm, and recalibrate after draining using a tds meter.

Learn to calculate the salt addition needed to maintain target TDS in a biofloc system, using freshwater salinity ranges, Tilapia example, and tank capacity.

measure water and soil salinity by passing an electric current between electrodes in a salinity meter; total dissolved solids show the concentration of dissolved particles in ppm or mg/l.

Improve water quality with aeration by bringing water and air into contact to remove dissolved gases, carbon dioxide, metals, and volatile chemicals, and support aerobic breakdowns and nitrification.

Explain how dissolved oxygen affects fish respiration, growth, stress, and survival, including optimal, stressed, and lethal zones, and its role in decomposition and nutrient conversion, overstocking, and waste buildup.

learn the recommended minimum dissolved oxygen levels for freshwater fish, including warm water around 5 mg/L, cold water around 6 mg/L, and koi around 8 mg/L, with 9–10 mg/L preferred.

Explore how oxygen enters water in ponds through air contact and photosynthesis, affecting dissolved oxygen levels. Track how light (sunrise to sunset and night) and seasonal temperature influence the system.

Explore how aerators boost oxygen in biofloc aquaculture, why fish gasp at the surface, and how temperature, filtration, and ammonia testing influence dissolved oxygen management.

Understand the difference between aeration and oxygenation in biofloc systems: oxygenation is dissolved oxygen influenced by water flow; aerators add oxygen, but dispersion relies on water movement, not bubbles.

Compare electromagnetic, diaphragm, and ring blower air pumps for biofloc systems, considering lpm, depth-related pressure, energy use, noise, maintenance, and backup power options.

Calculate lpm by dividing tank capacity by 60 minutes to determine air flow. For 10000 liters, this yields about 170 lpm; ensure 24/7 operation with backup pumps and solar inverter.

Learn how airstones disperse air into water via a pump, with six to eight stones near the substrate to prevent stagnation and protect fish by regulating bubble size.

Use a porous airstone to increase air-water surface area, boosting gas exchange and dissolved oxygen, while weighing the airline to stay submerged and prevent large bubbles.

Maintain air stones by rinsing, scrubbing, and drying after cleaning. Soak in a bleach solution (1 part bleach to 3 parts water) for 24 hours, rinse, and dry before storage.

Understand how water temperature drives metabolism, oxygen demand, and ammonia levels in aquatic animals, and learn to time operations and measure temperature accurately in biofloc aquaculture.

Explore how water temperature in biofloc systems drives fish metabolism, feeding, growth, and reproduction, and how heat or cold, oxygen, ammonia, and stress shape tank health and survival.

Explore how water temperature shapes biofloc formation, with 20–25°C forming stable flocs; higher temperatures cause flocs to lose integrity and sink as sludge, reducing dissolved oxygen and impacting fish health.

Explore desirable temperatures for cold, warm, and tropical aquaculture species in biofloc aquaculture systems, from sublethal below 20 C to ideal culture ranges of 25-30 C and tolerable 25-35 C.

Explore how water temperature drives dissolved oxygen in biofloc systems, with DO values at key temperatures, and identify temperature sensitive species such as carp, eel, and silver fishes.

Control temperature in a biofloc system by shading tanks, creating a complete closed environment, and recirculating water; insulate and heat as needed while monitoring electricity costs.

Use groundwater from a well as starter water for biofloc systems, avoiding stored underground water. Ensure the water is free of pathogens, nematodes, and protozoa to prevent fish mortality.

Identify nematodes as common fish parasites, and explain how viral, bacterial, and fungal pathogens threaten organs and overall health in freshwater, marine, and brackish fish.

Identify essential ingredients for floc development in biofloc systems, including water and frog development, probiotics, molasses, the carbon source, calcium carbonate, rock salt, and chloride.

Explore how probiotics—live microorganisms like Lactobacillus and Bacillus—boost fish health, immunity, digestion, and water quality, promote growth and reproduction, and offer alternatives to antibiotics within biofloc systems.

Explains what molasses is, a byproduct of sugarcane juice refinement used as a carbon source in biofloc aquaculture, and outlines two methods to prepare molasses through heating and stirring.

Explore fermented carbon for carbon farming by making Fco from organic sources like molasses and jaggery, fermenting 72 hours in an airtight container with probiotics to boost bacterial growth.

Learn how to prepare FCO for biofloc aquaculture, including a 50-liter 72-hour probiotic and molasses mix in an airtight container and slow-drip dosing at 30–40 ml per liter.

Explore organic carbon sources for biofloc aquaculture, including molasses, jaggery, cane sugar, rice bran, and tapioca byproducts; selection relies on local availability, cost, biodegradability, and efficient bacterial assimilation.

sanitize biofloc water with antifungal detergent or potassium permanganate, rinse and dry; check water parameters (pH 6.5–8.5) and apply probiotic with molasses, maintaining 22°C for two days before stocking fingerlings.

This lecture outlines a flow chart for biofloc water preparation, covering tank sanitization, groundwater filling, parameter checks (6.5–7.5), calcium carbonate adjustment, and molasses with probiotics.

Add calcium carbonate to adjust pH to 6.5–7.5, using one tablespoon per 1000 liters and avoiding overshoot. Add salt to maintain brackish salinity, supporting biofloc formation and parasite resistance.

Explain ammonia as a toxic, colorless gas produced by fish excretion, its link to feeding and protein, and its bacterial conversion to nitrate with a 0.01–0.02 mg/L threshold.

Identify the three main ammonia sources in biofloc systems: gill excretion from protein metabolism, breakdown of suspended solids, and dead fish, and learn to prevent spikes.

Explore ammonia toxicity in Biofloc systems, detailing toxic-to-non-toxic ratio and the impact of high pitch and temperature. Note that fish withstand 100x more total ammonia at 6.5 than at 8.5.

The lecture covers ammonia poisoning in fish, detailing early symptoms like gasping at the surface and lethargy, and later hemorrhages and gill discoloration as ammonia rises.

Regularly test ammonia to prevent buildup in biofloc systems; reduce feeding, pause feeding during stress, and balance carbon to nitrogen with a carbon source while water exchanges help control ammonia.

Explore total ammonia nitrogen (tan) and how biofloc systems use heterotrophic and autotrophic bacteria, carbon sources, and nitrite-to-nitrate conversion to keep ammonia in check.

Control total ammonia nitrogen in biofloc systems by managing carbon to nitrogen ratio: high C:N (12:1–20:1) during formation and six to ten to one during maintenance, using molasses.

learn how to calculate tan and dose carbon sources to control ammonia and support floc development in biofloc systems, using molasses, jaggery, or sugar at 6:1 or 10:1 ratios.

Explore how carbon to nitrogen ratio controls nitrogen levels in biofloc systems, using low protein feeds, monitoring total ammonia nitrogen, and drip dosing to stabilize water quality.

Understand how the C:N ratio controls ammonia in biofloc systems by maintaining a carbon source about ten times the ammonia present, using molasses as the example carbon source.

Calculate the carbon and nitrogen content in tilapia feed to determine the carbon source and the C:N ratio, using dry matter and crude protein.

Adjust carbon sources to achieve a 20:1 carbon to nitrogen balance in the biofloc system, calculating required molasses amounts and accounting for existing carbon content to maintain the target ratio.

Manage fish feed to maximize growth and maintain good health, minimize waste, and achieve optimum yield.

Evaluate how fish conditions, culture conditions (temperature, oxygen), and nutrition affect feeding in biofloc systems; analyze management factors like frequency, rate, and timing, plus prey and a food delivery system.

Evaluate criteria for selecting fish feed—species, age and size, feed quality, and feed conversion ratio—and compare natural feeds (plankton, phytoplankton, zooplankton) with ballots, flakes, freeze feed, tablet platform, granular form.

Explore life stages of fish and their feeding requirements, detailing feed particle sizes for fry, fingerlings, and growers, and a phased feeding schedule with biomass targets.

Evaluate feeding response in biofloc aquaculture by observing fish activity, weather, and how quickly feeds are consumed; classify from excellent to poor with examples like 5-10 minutes for excellent.

Assess the feeding response by monitoring feed suitability and water quality, including temperature and stressors, to detect overfeeding or underfeeding and take remedial actions; avoid feeding when response is poor.

In a biofloc system, feeding rates depend on fish size and growth; small larvae need high protein feed almost hourly, while larger fish require fewer feedings.

Calculate daily fish feed requirements in a biofloc tilapia system by applying body-weight percentage, multiplying by fish count, and adjusting for feeding frequency.

Explain food conversion ratio (FCR) in fish farming, how feed intake relates to growth, and how calculations impact profitability.

Identify marketable fish species with strong demand, estimate growth to six to seven months, and assess profitability under a biofloc system considering feed costs, conversion, and guidance from fishery boards.

Assess species for biofloc systems by physiology and tolerance to high solids and poor water quality, prioritizing those that digest microbial protein via floc, like shrimp and tilapia.

Explore fish species used in biofloc systems, including pangasius, tilapia, catfish, and shrimp, and discuss benefits for freshwater farming and marginal farmers.

Explore fish feeding strategies by zone—surface feeders access floating feed and surface air, middle-layer feeders rely on mid-water food, and bottom feeders graze the substrate within a biofloc system.

Calculate tank fish density by selecting a target biomass or marketable size, divide the 10,000 liter tank volume by per-fish biomass to estimate count, and adjust for 20 percent mortality.

Sanitize fish seeds before transferring to the biofloc tank to reduce stress, injury, and infections, using potassium permanganate, accustoming to tank water, dipping, hospital tank transfer, and antibiotic feeding.

Develop a seeding and harvesting plan tailored to your circumstances for better monitoring. Schedule harvest at the start of winter to reduce mortality and maintain tank temperature based on biomass.

Grading fish guides transferring juveniles, separating fast from slow-growing stock, selecting predator sizes for fry control, and partial harvesting for marketable fish in polyculture.

Sort and grade fishes to assess population status, reduce cannibalism losses, match feed sizes to fish sizes, separate sexes for breeding, and streamline sales and harvest stress.