Pond preparation checklist

Why preparation decides the crop

Most disease and growth problems in a crop can be traced back to what was left in the pond before stocking: organic sludge, pathogens, predators and acidic soil. A thorough preparation between crops is the cheapest insurance a farm can buy.

1. Drain and remove sludge

Drain the pond fully after harvest and remove the black organic sludge that collects at the centre and the feeding areas. Sludge consumes oxygen and releases ammonia and hydrogen sulphide once the pond is filled again.

• Scrape or pump out sludge from feeding zones and the drain area
• Repair dykes, inlets, outlets and screens while the pond is dry
• Remove weeds and debris from the banks

2. Dry the bottom

Let the bottom dry and crack in the sun, typically for one to three weeks depending on the weather and soil. Drying oxidises organic matter and kills many pathogens and their carriers. The soil should crack but not turn to dust.

3. Test the soil and apply lime

Measure the soil pH at several points. Agricultural lime (calcium carbonate) raises the pH and buffers the water; the amount depends on the soil pH and type, so follow your local extension service or supplier guidance. Spread lime evenly, with extra in the wet and sludge areas.

• Acidic soil (pH below about 6.5) needs liming before filling
• Use quicklime or hydrated lime only where disinfection is needed, and with care: they raise pH sharply

4. Fill, screen and condition the water

Fill through fine-mesh screens to keep out predators and wild fish. Fertilise as needed to build a healthy plankton bloom, which shades the bottom, feeds young stock and stabilises water quality. Wait until the colour and transparency are stable before stocking.

• Check pH, dissolved oxygen, salinity and temperature for several days before stocking
• Aim for a light green or brown bloom with a transparency of about 30 to 40 cm (Secchi disk)

5. Stock only when the pond is ready

Acclimatise seed slowly to the pond temperature and salinity, and record the stocking count, average weight and seed source on the day.

How the portal helps

Each pond has a preparation checklist built from your own template (Settings). Assign the steps, tick them off with dates and notes, and the pond can only be stocked once the preparation is complete. The record stays with the pond for the next crop.