Fish Feed & The Right Daily Ration

Pond fish are fed a daily ration as a percentage of their body weight, so first you need the biomass: number of fish × average weight. Daily feed = biomass × feed rate %. Over a period, total feed = daily feed × days. For example 2000 fish at 150 g each is 300 kg of biomass; at 3% that is 9 kg of feed a day.

Biomass is the total live weight of all the fish in the pond — number × average weight. Fish eat in proportion to their body weight, not their number, so biomass is what the feed rate is applied to. As fish grow, biomass rises, so the daily feed in kilograms goes up even though the rate as a percentage usually falls.

Feed rate is given as a percentage of body weight per day and depends mainly on fish size and water temperature. Small fry and fingerlings are fed at a high rate (often 5–10% of body weight), while larger grow-out fish drop to around 2–3% or less. Warmer water raises appetite; cold water lowers it. Use a size-appropriate rate and re-check as fish grow.

Young fish grow fast relative to their size and need a lot of feed per unit of body weight, so the percentage is high. As fish get bigger their growth slows relative to weight and their maintenance needs make up more of the ration, so the percentage falls. The kilograms fed still rise because the biomass is much larger.

Uneaten feed sinks and rots, fouling the water — oxygen drops, ammonia rises and fish get stressed or die, especially overnight. Over-feeding also wastes expensive feed and worsens the feed conversion ratio. Feeding to the calculated ration, then watching whether fish clean it up in a few minutes, keeps water clean and costs down.

Spread the daily ration over two to four feeds rather than dumping it all at once, so fish eat it before it sinks and fouls the water. Smaller fish and warm water suit more frequent feeding. The total per day stays the figure the calculator gives; you just divide it across feeding times.

Yes — the body-weight-percentage method is universal across carp, tilapia, catfish, rohu, catla and most pond species. The exact feed rate differs by species, size and temperature, so enter a rate suited to your fish; the biomass and feed maths stay the same.

Net a sample of fish, weigh them and divide by how many you weighed to get an average, then multiply by the total number for biomass. Sample regularly — weekly or fortnightly — because fish grow quickly and an out-of-date weight makes the feed ration wrong, usually too low.

They are good planning figures. Real intake varies with temperature, water quality, fish health, oxygen and feed quality. Use the calculator to set the ration, then adjust by observation — if fish finish the feed eagerly you may feed a touch more; if feed is left, cut back to protect the water.

Yes. All the maths runs in your browser; nothing about your pond, fish numbers or feed is uploaded or stored anywhere. Change the inputs and the daily feed, total feed and biomass update instantly.