Leca Clay Orchid/hydroponic Grow Media - 6 Lbs. Made of 100% natural clay. Pebbles are of various, round shape. Inert, pH-neutral, clean and decorative. Comes in a 6 lbs. bag For Orchids - porous structure provides excellent aeration and acts as a water reservoir. The size of the pebbles is perfect for medium to large Cattleyas and Laelias. For Hydroponics - Ensures good root aeration and prevents rotting, excess acidity and soil pests. Will approximately fill: (72) 2", (24) 3" pots, or (6) 5" mesh net pots.