Category: Aeration systems
Product guide · AerationPaddlewheel Aerators for Shrimp & Fish Ponds — Sizing & Quotes
Paddlewheel aerators are the workhorse of pond aquaculture — they add oxygen and, just as importantly, create the circulation that sweeps sludge to the pond centre. This guide covers how many horsepower your ponds actually need, how to read SOTR and SAE claims, where to place units, and what drives price.
Short answer: Paddlewheel aerators splash water to add oxygen to ponds and create circulation. Efficiency varies widely: an optimised design reached about 2 kg O₂/kWh in standard tests, while many typical designs reach 1 kg O₂/kWh or less. Ask for tested SAE at standard conditions.
What paddlewheel aerators do
- Surface aerators with paddle-tipped wheels driven by an electric motor and gearbox, mounted on floats and anchored across the pond.
- They transfer oxygen by splashing and entraining air at the surface, and simultaneously drive a rotational current that concentrates sludge in the pond centre for removal.
- Standard in shrimp ponds, tilapia and catfish ponds, and intensive lined systems; used with diffused aeration in biofloc and high-density units.
- Sold as 1 HP, 2 HP and 3 HP units with 4–10 paddle wheels; long-axle and 'aero-tube' variants suit deeper or larger ponds.
Typical specifications
| Parameter | Typical range | What it means for you |
|---|---|---|
| Unit power | 1, 2 or 3 HP (0.75–2.2 kW) | 2 HP four-wheel units are the global commodity standard for shrimp. |
| SOTR (standard oxygen transfer rate) | 1.2–2.2 kg O₂/h per unit | Measured in clean water at 20 °C, 0 mg/L DO — always ask for the test standard. |
| SAE (aeration efficiency) | 1.2–2.0 kg O₂/kWh | The number that governs your electricity bill; a 30% gap compounds over years. |
| Impeller / paddle count | 4, 6 or 8 wheels | More wheels spread transfer over a wider area and improve circulation. |
| Rotation speed | 80–120 rpm | Set by gearbox ratio; higher speed increases splash but also wear and shrimp stress. |
| Gearbox | Sealed oil-bath reducer | The single most common failure point — confirm seal type and spares availability. |
| Float / paddle material | HDPE or fibreglass floats, PP/HDPE paddles | UV stabilisation matters in tropical sites; cheap floats chalk within two cycles. |
| Duty | Continuous, often 12–24 h/day | Motor must be rated for continuous outdoor wet duty, IP55 or better. |
Sizing guidance
Aeration is sized from the biomass, feed rate and temperature at the end of the cycle — not from pond area alone. The area-based rules below are planning shortcuts; verify with an oxygen budget once the stocking plan is fixed.
| Project scale | Indicative aeration duty | Design notes |
|---|---|---|
| Semi-intensive shrimp, 5–8 t/ha/cycle | 8–12 HP per hectare | Typically 4–6 × 2 HP units per hectare, run mainly at night and after feeding. |
| Intensive shrimp, 10–20 t/ha/cycle | 16–30 HP per hectare | 8–15 × 2 HP units per hectare; near-continuous operation in the final third of the cycle. |
| Super-intensive / lined ponds, 25 t/ha+ | 30–50 HP per hectare | Combine paddlewheels for circulation with diffused aeration or oxygen injection for transfer. |
| Tilapia / catfish grow-out ponds | 4–10 HP per hectare | Lower feed loads and higher tolerance; emergency capacity matters more than continuous capacity. |
Oxygen budget rule of thumb: peak oxygen demand ≈ 0.20–0.25 kg O₂ per kg of feed applied per day, plus sediment and plankton respiration. Divide by the unit SOTR (derated ~65–70% for pond conditions, salinity and temperature) to get the number of units — then add standby capacity for the worst night of the cycle.
How to choose
- Compare SAE, not HP
Two 2 HP units can differ 30–40% in kg O₂ per kWh. Over a 120-day cycle running 16 h/day, that difference dwarfs the purchase price gap.
- Gearbox and seals
Ask for gearbox brand, seal rating and the price and lead time of a seal kit. Field failures are almost always gearbox or bearing, not motor.
- Motor protection
IP55+ continuous duty, thermal overload, and an electrical design that survives tropical humidity and voltage dips.
- Placement and circulation
Position units to create one consistent rotational current toward the centre drain; opposing currents kill both circulation and sludge control.
- Backup power
A generator or emergency aerators sized to hold DO through a two-hour outage; one lost night can lose a whole cycle.
- Spares and service
Confirm in-country service or a local stockist. Paddles, floats, seals and bearings are consumables, not one-time purchases.
What drives the price
- Unit power and wheel count
The base commodity spec; 2 HP four-wheel units set the market reference price.
- Motor and gearbox quality
Branded motors and sealed reducers add materially to price and to service life.
- Efficiency (SAE)
High-efficiency designs cost more up front and usually pay back inside one to two cycles on energy.
- Float and paddle materials
UV-stabilised HDPE versus commodity plastic changes replacement frequency in tropical sites.
- Order volume
Aerators are bought by the dozen or hundred — unit price falls sharply with container-scale orders.
- Freight
Bulky, low-density cargo; consolidate into full containers and confirm knock-down packing.
Unit prices and farm aeration budgets: not sourced. We have not found a dated public source for paddlewheel aerator prices, so no range is shown. Quotes depend on power, wheel count, motor and gearbox, freight and duty — request them on the same specification.
Common specification mistakes
- Sizing on pond area alone and discovering the shortfall in the final month of the cycle.
- Buying on HP and price without comparing SAE, then paying for it every night in electricity.
- Aerators placed so their currents cancel, leaving dead zones and sludge across the whole bottom.
- No emergency aeration or generator — a single outage during peak biomass can end the cycle.
- No spares budget for paddles, floats, seals and bearings, which are consumables.
Quote checklist for paddlewheel aerators
State these in your request so offers are priced on the same basis. If you do not know a value yet, write “unknown” — suppliers must then state the assumption they used, and our team flags differences when comparing.
- Unit power — your required value, or “unknown”
- SOTR (standard oxygen transfer rate) — your required value, or “unknown”
- SAE (aeration efficiency) — your required value, or “unknown”
- Impeller / paddle count — your required value, or “unknown”
- Rotation speed — your required value, or “unknown”
- Gearbox — your required value, or “unknown”
- What it serves — species or product, life stage or grade, and the capacity it must handle (peak load, not annual average)
- Site and climate — country, water source, temperature and salinity range or ambient conditions, power supply
- Quantity, destination and timing — number of units, delivery point and terms, required delivery and commissioning dates
- Documents you need — manuals, test or performance reports and any conformity or electrical certificates required where it will be installed; no certification is assumed
Capacity, operating conditions, materials, quantity, delivery terms and installation scope change the price most — see what drives the price above. Send this checklist as a reviewed project request.
Components that work with it
- Water quality sensors
DO probes start aerators automatically at night
- Shrimp pond liners
Aerator placement and anchoring are designed with the pond lining
Plan before you request quotes
Free calculators give a first sizing or cost scenario from your own inputs. Results are estimates to discuss with suppliers, not quotations.
Paddlewheel aerators — buyer questions
Get quotes for paddlewheel aerators
Send your duty, site conditions and target capacity once. We turn it into a comparable specification, send a confidential RFQ to producers and suppliers that may fit the project, and coordinate their replies on the same scope. Free for buyers; qualifying projects start at USD 250,000. FishMatch does not manufacture equipment, and buyers do not contact suppliers directly.
Related pages
Sources and review
- Efficiency of mechanical aeration — Global Seafood Alliance, 2015-11
Ranges marked "manufacturer-stated" come from public manufacturer documentation reviewed by FishMatch; they are examples, not guarantees, and supplier names are not shown. Last reviewed 2026-10-24.