Product definition
Sinking versus floating aqua feed: what the choice changes in your plant
Short answer
Buoyancy is a production specification, not a marketing label. Floating feed requires higher expansion and lower density, which reduces throughput per hour, raises drying load and demands tighter control of moisture, die configuration and knife speed. Slow-sinking feed sits between the two and is often the hardest to hold consistently. Sinking extruded feed allows higher density and higher throughput but still requires water stability control. Because capacity and energy differ by product, quote every buoyancy type separately with its own tonnes-per-hour figure — a single plant TPH number across mixed products is meaningless.
Questions buyers ask
Can the same line switch between floating and sinking feeds?
Extrusion lines are commonly designed for a product range, but each product has its own throughput, drying load and settings. Specify the full product portfolio in the RFQ, with capacity required per product, so the supplier engineers for the whole range rather than the easiest item.
Why does throughput drop on floating feed?
Floating feed requires greater expansion and lower bulk density, which means more volume and more moisture to remove per tonne. The dryer and cooler therefore handle a larger load per tonne produced, and the sustainable line rate falls.
Should buoyancy be a guaranteed parameter in the contract?
Density, durability and water stability can be defined as measurable acceptance parameters at commissioning, against a named recipe and test method. Agree the method before contract, not after.
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Species and farming method determine buoyancy; buoyancy determines density, density determines throughput. Fix this before requesting quotations.
Define your aquafeed line in a structured RFQHow buoyancy is achieved
- Degree of expansion at the die, controlled by moisture, temperature, pressure and recipe
- Bulk density target, verified continuously in production
- Die and knife configuration for the diameter and length required
- Drying profile, since residual moisture affects both density and stability
- Post-extrusion oil coating, which increases density and must be accounted for
Capacity impact by product type
- Floating, low-density products generally reduce throughput per hour
- Small diameters reduce throughput regardless of buoyancy
- High oil inclusion increases coating and cooling requirements
- Slow-sinking products demand the tightest process control window
Specification checklist per product
- Species and life stage
- Buoyancy class: floating, slow sinking, sinking
- Target bulk density range
- Pellet diameter and length
- Target fat, and split between in-recipe and coated fat
- Water stability requirement and test duration
- Durability and fines tolerance
- Required tonnes per hour for that specific product
Buoyancy classes and what they demand
| Class | Typical use | Production implication |
|---|---|---|
| Floating | Surface feeders, visible feeding control | Highest expansion, lowest density, highest drying load, lowest throughput |
| Slow sinking | Mid-water and marine species | Narrowest process window, tightest density control |
| Sinking extruded | Bottom feeders, shrimp, some marine species | Higher density and throughput, still requires water stability control |
Indicative guidance for scoping. Species requirements should be confirmed with your own nutritionist.
Questions buyers ask
Can the same line switch between floating and sinking feeds?
Why does throughput drop on floating feed?
Should buoyancy be a guaranteed parameter in the contract?
Continue the decision
Define your aquafeed line in a structured RFQ
Write the requirement once and send the same document to every supplier you are considering, including one you already prefer. FeedMatch sells nothing and takes no part in the contract.
Define your aquafeed line in a structured RFQScope and neutrality
- FeedMatch Group is an independent, supplier-neutral procurement platform. It does not manufacture, install or commission feed-processing equipment and is not an EPC contractor.
- FeedMatch does not sell feed, ingredients, premixes or additives and does not act as a trader.
- FeedMatch is not a bank, lender, credit provider or financial adviser. Financing, where relevant, is arranged by independent third parties.
- Calculator outputs and planning ranges on this site are indicative inputs for your own evaluation, not quotations, nutritional advice or performance guarantees.