3 gallons Soil Mix for a balance of Inorganic/Organic Bonsai Soil. 20% - 1/4" - 1/32" Natural Cascade Mountain Volcanic Lava rock. Pleasing mix of red, grey, black and white. 25% - 3/8" - 1/32" Natural Cascade Mountain Volcanic Pumice. 15% - Turface MVP. Turface is a high fired Calcined Clay. Particle size is 3/16 and under, has few fines, but has not been screened. 20% - Peat based growing media, unscreened. 20% - Fir Bark - 1/2" minus, unscreened. Approx. 3 gallons volume, fills 6 standard 1 gallon trade nursery containers. All natural, relatively light weight and porous. Our potting mix is hand packed and bagged with a reusable tie for easy storage after you have used part of the bag. If your potting mix dries before using, moisten it to keep dust from forming. Dust from any rock or potting soil product should not be inhaled and can be irritating for people with sensitive lungs. We are a commercial Wholesale / Retail Plant Nursery with over 30 years mixing specialty potting mixes. Check out our other listings of custom potting mixes to select the perfect mix for your bonsai or specialty plants. Scenic Hill Farm is a licensed Oregon nursery -- license # L0170090NG