Polyculture Stocking & Fill the Whole Water Column
Stocks catla
Indian major carps share a pond by feeding at different depths — enter the pond area and stocking density and the species split to get the total fingerlings and catla, rohu and mrigal counts.
Plan your carp stocking
Next: order 1,500 catla, 2,000 rohu and 1,500 mrigal fingerlings; the three species feed at different depths so they share the pond without competing.
Indian major-carp polyculture pairs surface-feeding catla, column-feeding rohu and bottom-feeding mrigal to use all natural food niches. Ensure the three percentages add up to 100%.
Polyculture stocking — key facts
- Total fingerlings
- area × density
- Per species
- total × species %
- Catla
- surface feeder
- Rohu
- column feeder
- Mrigal
- bottom feeder
- Why mix
- uses the whole column
- Density set by
- feed, aeration, water
- Privacy
- Runs in your browser; nothing uploaded
Three carps, three depths, one pond working flat out
The classic Indian major carp polyculture pays because each species works a different layer of water. Catla skims plankton at the surface, rohu feeds through the column, and mrigal grazes the bottom — so together they harvest the food at every depth instead of competing for one. Stocking the right total at a density the pond can support, then splitting it across the three by a sensible ratio, is the heart of composite fish culture.
This tool gives the total fingerlings and the catla, rohu and mrigal counts from the pond area, density and species split. Use it to order fingerlings, plan a balanced stock, and match the number to your feeding and aeration. Pair it with the Brooder Capacity, Silage Loss and Cattle Cooling Water tools for a full livestock-planning set.
Order the right fingerlings
Get exact counts for each species to buy.
Balance the depths
Split surface, column and bottom feeders.
Match the density
Stock what feed and aeration can support.
Plan any pond
Same logic for a tank or a large pond.
Frequently Asked Questions
How is the stocking calculated?+
Total fingerlings = pond area × the stocking density per unit area. The total is then split among the species by the percentages you set — catla, rohu and mrigal — so each count is the total times that species' share. The figures come straight from the area, the density and the ratio you choose.
Why stock catla, rohu and mrigal together?+
Because they feed at different depths and so share the pond without competing. Catla is a surface feeder taking plankton near the top, rohu is a column feeder working the middle water, and mrigal is a bottom feeder grazing the pond floor. Stocking all three uses the whole water column and the natural food in it, lifting total yield from one pond.
What is composite or polyculture fish culture?+
It is raising several compatible species together so the pond's food at every depth is harvested. The classic Indian major carp polyculture combines catla, rohu and mrigal, sometimes with other carps. Because the species occupy different niches they add up rather than compete, which is why composite culture out-yields stocking a single species.
What species ratio should I use?+
A common starting point spreads the stock across surface, column and bottom feeders so each layer is used, but the exact split depends on your market, pond fertility and management. There is no single right ratio — set the percentages you want and the tool gives the counts. Just make sure they add to 100%.
What stocking density is typical?+
Density depends on whether the pond relies on natural food, supplementary feed or full feeding and aeration — more inputs support more fish. A naturally fed pond stocks lighter than an intensively managed one. Use the density your management and water quality can sustain; the tool turns it and the area into fingerling numbers.
What happens if I overstock?+
Too many fish for the pond's food and oxygen means slow, uneven growth, stress, poorer water quality and higher risk of disease and kills. Stocking density has to match what the pond and your feeding and aeration can support. The calculator helps you set a number you can actually grow out.
Why split by feeding depth at all?+
Because it is what makes polyculture pay. If all the fish fed at one depth they would compete for the same food and the rest of the water column would go to waste. By matching surface, column and bottom feeders to their layers you harvest plankton, suspended matter and bottom detritus all at once from the same pond.
Can I add other species?+
Yes — common carp, grass carp or silver carp are often added to a major-carp pond to use extra niches such as bottom detritus or aquatic weeds. This tool focuses on the catla, rohu and mrigal split; if you stock more species, set their shares within your overall ratio and adjust the percentages accordingly.
Are the figures precise?+
They are accurate for the area, density and ratio you enter. Real stocking should also reflect water quality, expected survival, feeding and your target harvest size, so treat the counts as a plan. Order a few extra fingerlings to cover mortality, and refine the density against how the pond performs.