1、 Sea area selection: select the sea area with flat sediment bottom, water depth controlled at 8-20m, with a certain windproof performance, and can maintain a water depth of more than 2m under the spring tide line. The tidal current in the sea area is smooth, the seawater velocity is between 0.50 M / s and 0.70 M / s, and the salinity is between 25 m / s and 32 m / s.

2、 Seedling selection and transportation: the terminal part of Gracilaria lemaneiformis with good growth, disease-free, purplish red color and less miscellaneous algae was selected as the seed algae. The temperature should not exceed 20 ℃ during seedling transportation to prevent the algae from drying.

3、 Test methods: ① raft setting: raft spacing is 5-8m, 20-40 rows of rafts are set in each plot, and the spacing is 30-50m. The rafts are arranged vertically and horizontally in the shape of "field". ② Safety measures: the raft body facilities should not be placed too tightly, so that the raft body can float with the wind and waves to a certain extent; the float should be tied firmly, the rope buckle of the float should be tied tightly, and the joint of the rope and the floating pipe should be tied tightly; the lifting rope should be tied firmly on the floating pipe; the pile driving should be firm, and the depth of the pile driven into the soil layer in general sea area should not be less than 0.8m to prevent pile pulling; in order to reduce the harm of wind and waves Rafts should be set up for bias current. ③ Methods of seedling clamping and hanging: soak the seedling rope in seawater before clamping, so that the seedling rope is in a moist state. The amount of seedlings should be about 5g. A small cluster of seedlings should pass through the seedling rope, and a cluster of seedlings should be clamped every 5-10 cm. It should be clamped in the middle of the seedling, and the two ends should be exposed for 5-6 cm. When clamping seedlings, prevent sunlight exposure and algae drying to prevent algae dehydration. Connect the two ends of the clamped seedling rope with the hanging rope on the floating pipe, and hang them on the floating raft for breeding. The water temperature should be controlled at 10 ~ 27 ℃. ④ Management: use floating ball to adjust buoyancy and adjust aquaculture water layer. When the light is strong, the aquaculture water layer is regulated in the water surface layer. The seedlings were divided regularly.