Synthetic fertilisers usually contain a high concentrate Nitrogen, phosphorus, and potassium with some other micronutrients. Although they are in a readily available form that plants can use, they can also leach out of the soil quickly. This means that you may have to fertilise your plants several more times during a growing season. Organic fertilisers, on the other hand, can have a larger range of macro and micronutrients but need bacteria in the soil to help break them down in to plant food. We recommend using both the RE-250 and Biotic booster to achieve a long term wholistic fertilisation for your plants.