Orku 100L Coarse Perlite Soil Additive - Drainage Aeration Growing Medium Bulk100L Organic Perlite Coarse Premium Soil Expanded Medium Plants Hydroponics Bulk Perlite is a light, hard, aerated, white mineral, formed from volcanic glass, used in potting mixes to add open and porous drainage, provide aeration to plant roots and hold oxygen, a little moisture and nutrients from soluble fertilisers. This 100 litre bulk bag is perfect for creating your own potting mix or raised bed mix in bulk. Simply add compost, soil and other