Organic Soil Builder This blue-green algae becomes a tiny cover crop when sprayed onto soil. Apply on lawns, gardens, flowers or shrub beds. Without competing with other plants, it increases organic matter, reduces soil compaction, increases water retention, soil aeration and improves nutrient mobility. Also, the readily available Nitrogen stored in the algae's cells is slowly released into the soil at a rate of 0.5-1 lb/1,000 sq ft, per application. Apply monthly during the growing season. 1 Tbs mixed with water is enough for 1,000 sq ft; 8 oz covers 15,000 sq ft. Plan to use within a few months of purchase.