Aquaculture
Heavy Rain
Fish start floating on the pond surface just after heavy rain. This is as a result of fall in the pH and
production of hydrogen sulphide which makes the waters acidic and toxic. Water pH should be measured
after rain and necessary action should be taken. RandAqua 8886555529.
Alkalinity
Alkalinity in the pond water is the total amount of Sodium Bicarbonate plus Carbonate converted into Calcium Carbonate in pond water. For Vannamei, the Alkalinity levels desired are between 100-120 PPM during seeding, 120-150 during the shrimp is at 30-45 days old and 150-200 for the shrimp older than 90 days. For Black Shrimp, 80-100, 100-130 and 130-160 are desired respectively. RandAqua 8886555529.
Burnt Lime
Burnt lime is made by heating limestone at high temperature in a furnace to drive carbon dioxide from
the limestone and produce an oxide. The reaction of burnt lime and water releases considerable heat;
thus, calcium oxide reacts faster at lower temperature than at higher temperatures. RandAqua 8886555529.
Essential Nutrients
Calcium and magnesium are essential nutrients for aquatic plants and animals. Aquatic animals can get
calcium and magnesium both from the water and their food. Hardness usually is great enough to supply
enough calcium and magnesium for aquatic animals in fertilized ponds, and in ponds with feeding,
calcium and magnesium are obtained from the feed when the hardness is low. RandAqua 8886555529.
Fertilizers
Phosphate fertilizers applied to ponds stimulate phytoplankton growth and increase the base of the
food web. However, much greater aquaculture production can be achieved through the use of feed to
supplement natural productivity. Phosphorus from uneaten feed and the feces of culture animals can
cause excessive phytoplankton growth and associated degradation of water quality. RandAqua 8886555529.
Phosphate Ions
Phosphate ions can be absorbed rapidly by phytoplankton. Following pond fertilization, a large portion
of the applied phosphorus can be taken up by phytoplankton cells within a few hours. However,
phytoplankton have life spans of just one or two weeks, and when they die, the phosphorus in their
cells is quickly mineralized to soluble phosphate. RandAqua 8886555529.
Liquid Fertilizers
Liquid fertilizers are more effective than triple superphosphate and other granular fertilizers in pond
fertilization. Granules of phosphate fertilizer can settle to the bottom before completely dissolving.
Although the granules continue to dissolve, their close contact with soil particles favors the rapid
adsorption of phosphorus by the soil. RandAqua 8886555529.
Phosphorus
Regular additions of phosphorus every two to four weeks are necessary to maintain phytoplankton
blooms. High phosphorus inputs also favor the dominance of phytoplankton by blue-green algae. These
organisms often form undesirable surface scums and are subject to massive die-offs. The decay of dead
algal cells can cause dissolved oxygen depletion and massive mortality. RandAqua 8886555529.
Cobalt
Cobalt plays an important role in nitrogen fixation by rhizobium. An adequate supply of cobalt is
essential for the healthy growth of ruminants. Enhanced survival and growth of carp fry with the
application of cobalt singly or in combination with supplementary feed. Cobalt as a micro-nutrient
fertilizer in fish production and its availability in fishpond sediments is scanty or nonexistent. RandAqua 8886555529.
Copper
Copper can be an effective algicide and a parasite treatment in aquaculture ponds. Copper can be used
to control algae in ponds, including filamentous and higher algae. RandAqua 8886555529.