This mix has loads of nutrients, organic matter and minerals to help hold water. Acid Concentrate is designed especially for acid loving plants that like a lower pH for optimum growth. Use as a soil improver in very sandy soils. We recommend a ratio of 50:50. As a top up to existing beds, with a reasonable soil, it is fine to use it at a lower dilution rate. Acid Concentrate is NOT a planting medium on its own. It must be dug into the top 10 - 30 cms of existing soil.