Spirulina, the protein rich food supplement must be considered by the farmers as it is hassle free to grow, has low-investment cost and sold at good price.The tank size for spirulina production varies as per the quantity to be produced. For example to produce 6 kg dried spirulina every month, the tank size required shall be length 20ft x width 10ft x depth 1.5ft. Tank construction cost shall be approximately Rs 40 thousand.
The farm where spirulina will be cultivated must have good access to sunlight. It is the most important part of this farming. Sunlight needed is 20 c - 30 c, sufficient drinking water facility, good quality mother culture, nutrients and minerals namely sodium bi carbonate, sodium chloride , urea , magnesium sulphate , pottasium sulphate , ferrus sulphate and phosporic acid.
Once again assuming 6 kg production unit, tank area needed would be 1000 square feet, water required shall be 3600 - 4000 liters and mother culture 4 kg. Along with releasing mother culture in the tank, other nutrients to be added are 32 gram sodium bi carbonate, 20 gram sodium chloride, 0.8 gram urea, 2 gram potassium sulphate, 0.64 gram magnesium sulphate, 0.208 ml phosphoric acid and 0.20 ml ferrous sulphate. The water must be mixed once in a day for a week using a long stick for half an hour.
In the first season, it would take 7-10 days to harvest spirulina. Then after it can be harvested everyday. Using small plastic buckets spirulina is collected from the tank and poured into a mounted filter to remove excess water. The sieved spirulina should then be covered in a muslin cloth and 50 kg weight must be placed on the top of it. Finally the pressed spirulina is allowed to dry. It takes 5 - 7 hours every day for drying spirulina. Spirulina mother culture is sold at Rs. 1500 - 2500 per kg. It is only one time purchase as later farmers can have their own culture for the next spirulina production.