How this estimate is calculated
Biofilter Sizing Calculator · calculation version 3.0.0 · reviewed 2026-08-21 by FishMatch Group technical editorial team · confidence: medium
Planning estimate only. Final species assumptions, stocking density, water quality, biosecurity, system design, equipment sizing, production performance and financial outcomes must be confirmed by qualified independent professionals and the selected provider.
Purpose
Derive an indicative MBBR media volume and drum-filter flow from daily feed load.
How it was calculated
- TAN_kg_per_day = daily_feed_kg × TAN_per_kg_feed_g ÷ 1000
- media_volume_m3 = (TAN_kg_per_day × 1000) ÷ media_nitrification_rate_g_per_m3_per_day
- drum_filter_flow_m3_per_h = system_volume_m3 × turnover_multiplier
Where each value comes from
- Daily feed load
- Calculated
- TAN per kg feed
- Reference assumption
- Media nitrification rate
- Requires supplier confirmation
- System volume
- Buyer input
What the outputs mean
- Indicative MBBR media volume
- Daily TAN load
- Indicative drum-filter flow
Biological assumptions
- ≈30 g TAN per kg feed at ~45% dietary protein is a planning convention; actual excretion varies with diet and species.
Engineering assumptions
- Media nitrification rates (150–800 g TAN/m³/day) depend on temperature, dissolved oxygen, pH, alkalinity and biofilm maturity.
- Media volume is not reactor volume: K1/K3 media is typically filled at 40–60% of reactor volume.
Limitations
- Does not size CO₂ stripping, degassing, alkalinity dosing, denitrification, UV or ozone — all of which are required in a real RAS.
- No drum-filter model, micron rating, biofilter vendor or reactor geometry is selected.
What must be confirmed before you build
- Integrator biofilter design at design temperature
- Alkalinity and pH control strategy
- CO₂ removal and degassing design
- Media supplier performance data
Sources for default assumptions
Next step
Review every value above, correct anything that does not match your site, then transfer the reviewed figures into a structured RFQ. Nothing is sent to any supplier until you approve it. Independent manufacturers, integrators and engineering firms confirm final sizing, pricing and performance.