Which parameters are critical for whitefish farming in ras?
The critical parameters are temperature, dissolved oxygen, pH, ammonia, nitrite, nitrate, stocking density, feeding rate, hydraulics and redundancy of key equipment.
Technology - RAS for whitefish
Technology for growing whitefish in closed RAS systems
Whitefishes are a cold-water group of salmonids. The key to RAS is: stable low temperature, high oxygen, clear water and a stable nitrogen cycle. We analyze environmental parameters, design features, growth, incubation and farm composition.
Juvenile whitefishes in the nursery pool
Short answer
Whitefish farming in RAS explains how to organize fish production with controlled water quality, oxygen, temperature, stocking density, feeding and routine operations. Whitefish species are cold-water fish, so temperature stability, water quality and careful juvenile handling are central to the design.
What is a whitefish RAS farm?
A whitefish RAS farm is a farm with repeated use of water, where the quality of the environment is maintained by a cleaning and preparation system: mechanical cleaning, biofiltration, gas mode / degassing, oxygen, automation.
The main feature of the group
Whitefish are cold-water: in a recirculation system the task is to maintain a stable low temperature, high oxygen and clear water, while the biofilter works slower and requires a reserve.
History and types
Industrial whitefish farming developed against the backdrop of a decline in natural populations. In the 1980s, GosNIORH created feed LS-81 and MS-84 and biotechnology for growing planting material, in the 1990s they developed commercial cultivation on artificial feed, and in the 2000s - the formation of replacement broodstock in industrial conditions.
Species (Coregoninae)
- Whitefish
- Peled
- vendace
- Omul (by region)
- Muksun
- Cheer
- Nelma (less often - a complex object)
- Hybrid peled × whitefish
Basic Environment Settings
Guidelines for regimes for pool rearing of juveniles. Target values are specified by water source, density and technology.
| Indicator | Norm/guideline | Comment |
|---|---|---|
| T (seasonal mode) | May 7–14; June–Aug 14–22; Sep 6–12 °C | At T>20 °C the risk of hypoxia increases - strengthen O₂ control. |
| T (optimum growth) | 17–20 °C | Larvae up to 1 g - top 20 °C; 3–5 g — 17–19 °C. |
| O₂ (outflow) | 7–9 mg/l (70–90%); acceptable 6.0–6.5 | Critical ~3 mg/l: stop feeding, aeration, increased flow. |
| pH | 6.8–8.0 (bottom 6.0, top ~8.5) | Monitor together with CO₂ and O₂. |
| CO₂ | 5–15 mg/l (up to 20 is acceptable) | During growth there is flow and degassing. |
| BOD₅ | 1–5 mgO₂/l (up to 7) | Growth is a sign of organic contamination. |
| COD | 15–30 mgO/l (up to 50) | Needs improved filtration. |
| Ammonium (N-NH₄⁺) | 0.10–0.40 mgN/l (>0.5 is unacceptable) | Non-ionized ammonia risk - load restrictions. |
| Nitrite (N-NO₂⁻) | 0–0,005 mg/l (>0.02 is unacceptable) | Danger of toxicosis; control with BOD and O₂. |
Growing options
cages
Subject to availability of reservoir and permits; conditions depend on the external environment and regulations.
Forward flow
Simpler in engineering, but critically tied to the source of water: flow rate, quality, seasonality.
RAS
Maximum controllability and biosafety, year-round operation; higher requirements for engineering.
Design Features
- Temperature: where do we get the “cold” from (source / heat exchanger / chiller) and how do we maintain stability over the seasons.
- Slow biofilter: at low temperatures, a reserve is laid in the area and volume of the biofilter and the maturation time.
- Gas mode (O₂/CO₂): degassing, oxygenation, oxygen reserve.
- Cleaning and transparency: sequence of units up to the biofilter, regular washing.
- Thread separation: quarantine, separate incubation, “clean” zones.
- Redundancy: pumps, oxygen, emergency power, alarm.
Flow calculation
Landmark - constant flow up to 0,6 l/s to the pool/flume. Water consumption is calculated through oxygen consumption by fish and the permissible decrease in O₂ between inflow and outflow: Qw = (ORC x M) / delta O2; critical ichthyomass Mkr = Qw / WR. Allowable exhaust O₂: 6.5 mg/l at 18–20 °C and 6.0 mg/l at 12–17 °C.
| Average weight, g | ORC20, mgO₂/(s kg) | WR, l/(s kg) | Critical biomass at Qw approx.0.6 l/s, kg |
|---|---|---|---|
| 0,008–0,3 | 0,744 | 0,29 | 1,6 |
| 0,3–4,0 | 0,313 | 0,12 | 4,5 |
| 4,0–20,0 | 0,208 | 0,08 | 7,5 |
Example for juvenile muksun at 20 °C, 100% O₂ saturation and permissible outlet O₂ 6.5 mg/l.
Growth (example: peled)
Growth dynamics of juvenile peled on artificial feed in swimming pools: in ~4.5 months they received 7–9 g with a yield of 38–80% (average monthly T 10–16 °C, O₂ 5,0–9,2 mg/l).
Growing technology
Incubation of eggs. Weiss devices 8 each l (~5 l caviar ≈ 300 thousand eggs). Mode: T 2.7–8.5 °C, O₂ 7–11 mg/l (not lower than ~60%), pH 6.5–7.5. Water consumption by stage: 2.2–2.4 → 2.6–2.8 → up to 3–3.5 l/min. Incubation 160–180 days, embryo yield 60–70%.
Larva and fry. Stocking of nursery tanks on days 2–5 after hatching. Switch to food: at 7–10 °C - 2nd day, at 5-6 - 3rd, at 3-4 - 4-5th. On the outflow there are “lanterns” (sieves No. 11–12 → No. 7), then grates 2 mm.
Growing up to 10 g. By weights with sorting; feed LS-81 (start) and MS-84. Control of water quality and palatability.
Diagram of a nursery pool (tray) with an outflow unit and a “lantern” filter.
Growing standards (peled)
| Indicator | Larvae | Fry | Fingerlings |
|---|---|---|---|
| Water depth, m | 0,2 | 0,2 | 0,3 |
| T water, °C | 8–16 | 15–18 | 10–16 |
| Weight, g (start→end) | 0,003 → 0,03 | 0,03 → 1,0 | 1,0 → 10,0 |
| Feed | LS-81 (start) | MS-84 | MS-84 |
| Krupka, mm | up to 0.5 | 0,5–1,0 | 1,0–3,0 |
| Feedings/day | 16 | 16 | 8 |
| Feed Payment (FCR) | 2,0 | 1,5 | 1,5 |
| Density, thousand/m³ | 50 | 25 | 2,5 |
| Survival rate, % | 95 | 60 | 95 |
| Period, months | 1 | 1 | 2 |
Planting material
Obtained in the form of eggs, larvae or juveniles. Whitefish caviar: diameter 2.3–3.0 mm, weight 7–8 mg, 50–60 thousand pieces/l.
- Transportation of larvae: in bags with oxygen (water/oxygen ≈ 1:2). Peled at 4–7 °C: up to 12 h - 8–10 thousand/l, up to 24 h - 4–5 thousand/l, up to 36 h - 3 thousand/l.
- Transport of juveniles (0,4–2 d) in summer at 14–17 °C: up to 15–17 kg/m³. Feeding is stopped 1 day (juveniles) or 2 (fingerlings) before transportation.
Site and building
- Water: analysis + flow rate stability; for RAS - quality of recharge and water exchange modes.
- Electricity supply 380 B + redundancy of critical nodes.
- "Cold": cold source/heat exchange/chiller and building insulation.
- Sewerage and collection of wash water; ventilation and dehumidification with large water surfaces.
- Zoning: incubation/fry separately, goods, water treatment, warehouses, sanitary areas.
Farm composition
- Incubation (Weiss devices) - if “from the calf”
- Larva and early growth + fine fur cleaning
- Growing by weights (sorting, transfers)
- Product block or block of planting material
- RAS core: mechanical cleaning → biofilter → degassing → oxygen → pumping
- Slurry unit and rinsing waters
- instrumentation and automation and alarm
- Quarantine (preferably separate)
Equipment and costs
Equipment
- Incubators (Weiss et al.), sorting tanks
- Trays and pools (Swedish 2x2 m, Yeisk 4.2×0.7 m) + “lanterns” and grilles
- Feed dispensers and feed storage
- Fur cleaning (drum/sieve), biofilter, pumps
- Oxygenation (cones/columns), aeration, CO₂ degassing
- Water control: oximeters, sensors, tests
- Redundancy: emergency oxygen, UPS/generator, alarm
Resource costs
- Electricity: pumps, mechanical cleaning, automation, oxygenation, possibly a chiller.
- Water: make-up + wash water.
- Stern: main OPEX; FCR in the early stages is 1.5–2.0.
- Planting material: eggs/larvae/fry, logistics and quarantine.
- Staff: fish farmer + RAS operator/engineer.
Project implementation
Technology design — our profile (service “Design of fish farms”).
Building design.
Supply of equipment.
Construction of a building.
Installation of technology.
Launch and stocking.
We will design a RAS farm for whitefish
From temperature and gas conditions to the selection of equipment and working documentation.
Completed projects
Incubation and fry farms for whitefish: Buryatia (up to 6 million pieces) and peled in the Magadan region.
Buryatia, up to 6 million units.Complex layout
Buryatia, up to 6 million units.Technological diagram
Buryatia, up to 6 million units.Module layout
Magadan regionHatchery and fry workshop (peled)
FAQ
Frequently asked questions
Clear answers to the questions that usually appear before a RAS fish farm project starts.
Can standard equipment be used without calculation?
It is risky. Equipment must match the species, biomass, feed load, water quality and building layout. A generic set can lead to weak filtration, unstable oxygen or difficult maintenance.
How is the technology selected for a project?
The choice depends on fish species, target capacity, water source, climate, available building, energy costs, staff skills, market format and the required level of automation.
Calculate a whitefish RAS farm based on your conditions
Describe the type of fish, purpose (fry / product / RMS), region and available water source - we will prepare a preliminary calculation and propose a module configuration.
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