Grow stone lift is the ideal drainage layer for all your indoor & outdoor plants. Simply add lift to the bottom of your container & breath fresh air into your roots. Lift allows air to enter the inner core of your roots helping them dry evenly & allows excessive water to drain away. These highly porous large stones are lightweight, clean & provide aeration to roots superior to any other substrate on the market. The best part is they are made in the USA from 100% recycled glass!