Hydrated Lime or Calcium Hydroxide is used to breakdown organic silt in situ. The dose rate is 250-300kg per hectare or roughly 250-350lbs per acre.
The best time to apply hydrated lime is December through to March.
Hydrated Lime should be evenly applied to the waters’ surface where required. We would suggest that a maximum of 20% of the water area is treated at any one time.
Hydrated Lime can be harmful to aquatic life.
It is ideal for spot treatment of small silty areas within lakes and ponds.
Liming To Sterilize
Hydrated lime, or calcium hydroxide, is also used in commercial fish production ponds. While it will increase total hardness (the calcium component), and temporarily increase the total alkalinity (the hydroxide component), its primary effect is to raise the pH of mud and water quickly and dramatically.
Ponds should be drained and cleaned prior to applying this product. Enough hydrated lime should be added to cover the entire pond bottom with a thin layer (approximately 900kg per acre), and then water added. The pH in the upper layer of the mud and in the water will rapidly rise to 12 or higher, a level which will kill most disease agents and/or pests. The elevated pH will last for about a week, prohibiting any stocking of fish. Always check the pH before stocking.
Adding hydrated lime is not recommended when fish are present in the pond. The rapid increase in pH is almost always lethal to fish.
The use of hydrated lime is recommended when there is any concern of carrying diseases or pests over to the next crop. It has limited, long-term impact on total alkalinity and pH.
Appropriate safety measures should be taken to prevent he inhalation of its dust, those applying it should wear hooded suits, gauntlet gloves, face masks and goggles.
Liming should not be carried out in wet or windy weather.