Practical Guide to Pond Mulching for Frost Protection

Practical techniques for pond mulching and frost protection are mainly used when the winter temperature drops below 10°C, as most warm-water fish (such as tilapia, pufferfish, largemouth bass, etc.) find it difficult to overwinter safely in ordinary ponds. Before cold air arrives, the pond water should be deepened in advance according to the pond conditions, and suitable greenhouse film should be used to cover the pond, so as to maintain the pond water temperature and ensure that fish and shrimp overwinter safely.
Main technical contents:
1. Simple greenhouse overwintering method: When the pond width is less than 20 m, steel pipes can be used across the entire pond to support an arched frame, covered with two layers of plastic film and connected to the pond edge to form a sealed cover. The film can be sealed around the edges with mud. The greenhouse should be about 60-80 cm higher than the pond. If the temperature is below 0°C, steam pipes or hot water pipes can be used to heat the pond water to ensure that fish and shrimp overwinter.
2. Simple half-greenhouse overwintering method:
(1) When the pond width is greater than 20 m, build a windbreak barrier 1.5-2 m high on the north side of the pond using crop straw or soil, and use moso bamboo to support a simple greenhouse between the windbreak barrier and the pond to prevent the pond from freezing.
(2) Build drainage ditches around the fish pond to prevent snowmelt from outside the pond from flowing into the pond.
(3) On the north windbreak wall, at 40 cm from the pond bottom, dig 1-2 cold-shelter holes 2 m deep and 0.8 m in diameter. The walls of the holes can be built with bricks or fitted with ceramic pipes, so that fish can hide in the cold-shelter holes when a cold wave strikes.
(4) If fish are found to have already suffered cold injury, apply as soon as possible a mixture of table salt and baking soda at a concentration of 4 parts per 10,000 to prevent the occurrence of water mold disease.