Polishing pond for Magur fish in ETP treated water.

Polishing pond for Magur fish in ETP treated water.

 Oxygen level in the tanks should exceed 3 mg/l. If the magur fish tanks are supplied with turbid water it is advisable to filter it with through a sand filter and to aerate the tanks at night for maintaining oxygen level by using an air blower The aeration grid should be one feet above the bottom of the tank so that mud can settle at the bottom..Magur requires mud. .

A tank containing such a fish group required approximately 5 liter/min water supply. Depth of fish tanks should be 0.5–0.75 m. Let us take water depth 0.75 meter.The freeboard of the tank should be 0.5 meter so that fish don’t jump out. So total depth of tank is 1.25 Meter. Volume of the tank should be 10,000 liter. Normally it should be square in size. So length and width of tank will be 4 Meter by 4 meter. 

For avoiding the direct contact between tank wall and fish it is better to cover the inner surface of tank with polyethylene sheet.

Inlet water should be sprayed in the tank from a perforated PVC tube throughout the length.

Outlet water will overflow from a overflow weir at the outlet side. The top of the overflow weir will be covered by net/mesh. The proper mesh size is 1.0–1.5 mm

Most efficient way of plankton maintenance is frequent manuring with small doses of poultry or cattle manure. In addition to plankton maintenance, frequent manuring maintains an active and effective bacterial population in pond water. It facilitates decomposition of metabolites hampering fish growth. Poultry (5–15 kg/bigha) or cattle (10–20 kg/bigha) manure is sufficient for frequent treatment of pond.

Daily brushing of wall and bottom of the tanks is essential. Moreover, when there is deterioration in water quality, 10–20 % fresh water replacement is suggested.

Lime is used for killing different living organisms remaining in muddy pools after dewatering of ponds.

IF MAGUR SURVIVES IN THE POLISHING TANK, IT MEANS THE ETP IS RUNNING PROPERLY.

TANK SIZE : 4 x 4 x 1.25 Meter. Water depth = 0.75 Meter. Free Board=0.5 M