How is the number of fingerlings to stock found?

Maximum biomass equals the volume multiplied by the maximum density in kilograms per cubic metre. Dividing that biomass by the target harvest weight per fish gives the number of fish the system can carry at harvest, which is the number to stock allowing for survival.

What is a typical maximum density?

It depends heavily on the species and aeration. Static earthen ponds often hold 1 to 5 kg per cubic metre, aerated ponds 5 to 20, intensive tilapia tanks 20 to 40, and recirculating catfish systems 40 to 100 or more with strong aeration and water exchange. Use the figure your system can actually support.

How is daily feed loading calculated?

Daily feed equals the current biomass multiplied by the feeding rate, which is a percentage of body weight per day. Fingerlings are fed at 5 to 10 percent of body weight, growers at 2 to 4 percent, and fish near harvest at 1 to 2 percent, decreasing as they grow.

Why does aeration matter for density?

Fish consume oxygen, and at high biomass the natural oxygen supply of the water is exceeded, causing stress, slow growth, or kills. Aeration raises the safe carrying capacity. The tool flags when your chosen density is in the range that normally requires mechanical aeration.

Should I account for expected mortality?

Yes. Stock slightly more fingerlings than the carrying number so that, after expected losses, the surviving fish reach the target biomass. Enter a survival percentage and the tool scales the stocking number up accordingly.

Aquaculture Stocking Density Calculator

Stocking a pond or tank correctly means matching the number and final size of fish to what the water volume can safely carry. Overstock and you get poor growth, disease, and oxygen crashes; understock and you waste capacity. This tool sizes the stocking number, maximum biomass, and daily feed from your volume, species density, and target weights.

How it works

The carrying capacity sets everything else:

volume        = area × depth   (or entered directly)
max biomass   = volume × max density (kg/m³)
fish at harvest = max biomass / target harvest weight
stocking number = fish at harvest / (survival % / 100)
current biomass = stocking number × stocking weight per fish
daily feed    = current biomass × (feeding rate % / 100)

The maximum density you enter is the lever that depends on aeration and water exchange — the tool flags when that density is in the range that normally needs mechanical aeration so you do not silently plan beyond what the system supports.

Tips and example

A 200 m³ pond stocked for tilapia at a safe 8 kg/m³ can carry 1,600 kg at harvest. At a 0.5 kg target harvest weight that is 3,200 fish, or about 3,556 fingerlings allowing for 90 percent survival. If those fingerlings weigh 20 g each, the starting biomass is about 71 kg, and at a 6 percent feeding rate you feed roughly 4.3 kg per day at the start, rising as the fish grow. Re-run the feed figure weekly as biomass increases, and never exceed the density your aeration can hold.