An alternative salt nutrient mixture for plant growth, wherein one or more of the following nutrients is present as a carbonate: nitrogen (eg ammonium), potassium, calcium, magnesium, iron, manganese, boron, zinc or copper and/or one or more of the following nutrients is present as a nitrate: nitrogen (eg ammonium), potassium, calcium, magnesium, iron, manganese, boron, zinc or copper.