1. Seawater intake requires clean seawater quality, no pollution and no sundries; Water pumps and faucets are covered with filters to reduce the entry of algae.
2. The sewage outlets that regularly discharge waste water from nurseries and nursery ponds should be far away from the water intake, with a distance of not less than 50 meters.
Second, the greenhouse foundation treatment The pool in the greenhouse is an above-ground structure. According to the needs of aquaculture, the pond must meet the requirements of non-leakage, so the anti-seepage treatment of the pond bottom and the joint between the pond bottom and the pond wall is particularly important. After the greenhouse construction, tamp the ground in the greenhouse and lay 10 cm gravel cushion, and then pour the ground with C20 concrete on site.
III. Design and Construction (Take a 300-square-meter water shed as an example)
1. The outer wall of the nursery is built with hollow bricks (size: 40cm× 20cm× 19cm), with a clear length of 35m, a clear width of 12m, a flat mouth height of 2.2m and a maximum vault height of 4m. There are six aluminum alloy windows on both sides of the long side wall of the greenhouse, and there are no doors and windows on the short side gable. The greenhouse roof adopts reinforced arch beam with a span of12m. It is covered with a whole piece of black plastic cloth and covered with a straw curtain, which is firmly fixed to prevent wind damage.
The size of the pool in the shed. The walls around the pool are made of bricks (24cm× 12cm× 5cm). 70 # cement mortar jointing, wall thickness of 25cm. Wall thickness of the small pool separated from the pool 13 cm. The pool is divided into two parts along the width of the greenhouse, symmetrically arranged, with sidewalks and drainage channels in the middle. The net length and width of each small pond are 5 meters and 2 meters, and the depth of the pond depends on seedling raising and seedling protection. If the seedlings are protected, the pond depth is 1.2 m ~ 1.8 m, generally1.5 m; If only the seedlings are protected, the depth of the pond is 0.8 meters. Each small pond is reserved with a water inlet and a water outlet. The water inlet is on the side near the outer wall, and the water outlet is on the side near the sidewalk. The water outlet is 3 cm from the bottom of the pond and is controlled by a valve. Small pools are not connected and independent, and 30 small pools can be arranged for 300 square meters of water. Plastering treatment adopts "five-layer working face method" to prevent leakage. There are sidewalks and drains between the two rows of small pools, with a width of 0.8m ~1m.
3. The boiler room temperature and water temperature are low in winter and spring, which is not conducive to seedling raising and seedling protection. Therefore, a heating boiler room should be built to supply heat to the shed to ensure that the water temperature is between15℃ and16℃, which is beneficial to the healthy growth of sea cucumber seedlings. The radiator can be installed on the wall or directly put into the pool. The heating form can be water heating or air heating. For large-scale seedling-raising and seedling-protecting enterprises, taking a water body of 2,000 square meters as an example, if a boiler is used for heating, only 70,000 yuan of coal needs to be burned a year, plus pipes, radiators and boilers, which requires a lot of investment. In order to reduce investment, a seawater well can be drilled in a proper position. Drilling a seawater well with a depth of 70-80 meters requires only 80,000 yuan after supporting a water pump, which is more economical than burning a boiler.
4. The seawater temperature in seawater wells is 15℃ ~ 16℃ all the year round, which is close to constant temperature. This temperature is the most vigorous temperature for the growth of sea cucumber. It is a feasible method to extract constant temperature water from seawater well and directly transport it to the pool in greenhouse, which is beneficial to the growth of sea cucumber seedlings, greatly reduces the cost and solves the problem that the heating temperature is difficult to control.
5. PVC pipes with a diameter of 100 mm are fixedly laid along the top of the pool walls of the two long sides of the greenhouse, and three-way short pipes are set to deliver water to the pools according to the number of pools, and each short pipe is controlled by a valve. In order to reduce investment, some self-employed people can use movable hoses instead of fixed pipes to deliver water to various pools respectively. The sidewalk doubles as an indoor drainage channel. The outlet is on the gable side of the greenhouse (the inlet pipe and outlet pipe have been reserved during construction), and the discharged wastewater is discharged into the sea far away from the seawater intake through the drainage pipe (diameter 150 mm) outside the greenhouse.
6. Placement standard of seedling-raising and seedling-protecting basket in the pond The sea cucumber seedling-raising basket is a white plastic basket with a quadrangular shape, with an upper opening size of 43cm× 40cm, a lower opening size of 33cm× 30cm and a height of 40cm. Small ponds generally have 3-5 rows of baskets, each row 12 baskets. The top of the basket is 40 cm away from the water surface, and the water depth should not be too deep, otherwise the sea cucumber seedlings can't bear too much water pressure and die easily. When raising seedlings, two layers are hung along the water depth, the bottom basket is directly hung on the bottom of the pond, and the upper basket keeps a distance of 20 cm ~ 30 cm. Generally, 50 ~ 60 baskets should be hung in each pond. Only one layer is hung when protecting seedlings. Generally, seedlings can emerge in 10 to 15 days.