{
    "name": "Aquaculture Dissolved Oxygen Demand Calculator",
    "url": "https://calculators.geekmidst.com/calculators/aquaculture-dissolved-oxygen-demand-calculator",
    "markdown": "https://calculators.geekmidst.com/calculators/aquaculture-dissolved-oxygen-demand-calculator.md",
    "category": "Agriculture",
    "description": "Estimate how much oxygen a fish stock consumes from its biomass and consumption rate, the water flow that would supply it, and the aerators needed.",
    "summary": "Fish oxygen use is biomass times a consumption rate. To keep up, inflowing water must carry that much oxygen above your minimum level, or aerators must add it.",
    "also_called": [
        "Fish oxygen consumption calculator",
        "Aerator requirement calculator"
    ],
    "applies_to": "Worldwide",
    "last_updated": "2026-10-29",
    "computation": "Results are computed in the visitor’s browser on the HTML page. This API describes the calculator; it does not compute results.",
    "inputs": [
        {
            "name": "biomass",
            "label": "Fish biomass",
            "type": "number",
            "default": "2000",
            "unit": "kg"
        },
        {
            "name": "o2_rate",
            "label": "Oxygen consumption rate",
            "type": "number",
            "default": "300",
            "unit": "mg O₂ per kg fish per hour"
        },
        {
            "name": "do_in",
            "label": "Dissolved oxygen of inflow water",
            "type": "number",
            "default": "8",
            "unit": "mg/L"
        },
        {
            "name": "do_min",
            "label": "Minimum dissolved oxygen to keep",
            "type": "number",
            "default": "5",
            "unit": "mg/L"
        },
        {
            "name": "aerator",
            "label": "Oxygen added per aerator (field rate)",
            "type": "number",
            "default": "0.5",
            "unit": "kg O₂/h",
            "optional": true
        }
    ],
    "outputs": [
        {
            "key": "demand_kg_day",
            "label": "Oxygen demand",
            "format": "number"
        },
        {
            "key": "demand_g_h",
            "label": "Oxygen demand",
            "format": "number"
        },
        {
            "key": "flow_l_min",
            "label": "Water flow to supply it",
            "format": "number"
        },
        {
            "key": "flow_m3_h",
            "label": "Water flow to supply it",
            "format": "number"
        },
        {
            "key": "flow_us_gpm",
            "label": "Water flow to supply it",
            "format": "number"
        },
        {
            "key": "aerators",
            "label": "Aerators needed",
            "format": "integer"
        }
    ],
    "formula": {
        "text": "Demand (mg/h) = Biomass × Rate;  Flow (L/h) = Demand ÷ (DO_in − DO_min);  Aerators = ⌈Demand (kg/h) ÷ Aerator rate⌉",
        "variables": {
            "Rate": "mg of oxygen used per kg of fish per hour",
            "DO_in": "oxygen in the incoming water, mg/L",
            "DO_min": "lowest oxygen level you will allow in the tank or pond"
        }
    },
    "worked_example": {
        "inputs": {
            "biomass": "2000",
            "o2_rate": "300",
            "do_in": "8",
            "do_min": "5",
            "aerator": "0.5"
        },
        "steps": [
            "Demand = 2,000 kg × 300 mg/kg/h = 600,000 mg/h = 600 g/h, or 14.4 kg a day.",
            "Each litre of inflow can give up 8 − 5 = 3 mg, so flow = 600,000 ÷ 3 = 200,000 L/h = 200 m³/h.",
            "Aerators: 0.6 kg/h ÷ 0.5 kg/h = 1.2, so 2 aerators."
        ],
        "result": "Two tonnes of fish using 300 mg/kg/h need 14.4 kg of oxygen a day: 200 m³/h of water flow or two 0.5 kg/h aerators."
    },
    "interpretation": "Oxygen use peaks after feeding and at high temperature, and ponds lose oxygen to algae and sediment at night. Size aeration for the worst hours, not the daily average.",
    "assumptions": [
        "Consumption rate is constant over the period.",
        "The fish are the only oxygen consumer."
    ],
    "limitations": [
        "Pond respiration by plankton and sediment, and oxygen added by photosynthesis, are not included."
    ],
    "rules": null,
    "faqs": [
        {
            "question": "Where do I get the oxygen consumption rate?",
            "answer": "From research or extension data for your species at your water temperature and fish size, or from your equipment supplier. Small fish use more oxygen per kg than large fish."
        },
        {
            "question": "Why is the aerator rating reduced?",
            "answer": "Makers rate aerators in clean water with zero oxygen. In a stocked pond, transfer is lower, so use a field figure rather than the standard rating."
        }
    ],
    "sources": [],
    "related": [
        {
            "name": "Fish Pond Stocking Density Calculator",
            "url": "https://calculators.geekmidst.com/calculators/fish-pond-stocking-density-calculator"
        },
        {
            "name": "Aquaponics Water Flow Calculator",
            "url": "https://calculators.geekmidst.com/calculators/aquaponics-water-flow-calculator"
        },
        {
            "name": "Irrigation Pump Power Calculator",
            "url": "https://calculators.geekmidst.com/calculators/irrigation-pump-power-calculator"
        }
    ],
    "disclaimer": null,
    "publisher": "GM¹X CalcVerse"
}