GROW!T horticultural clay pebbles are made from 100 percent natural clay. They are clean, pH stable and offer great aeration and drainage in hydroponics, especially in flood and drain, deep water culture and drip feed systems. Due to their unique structure and ability to cover a large surface area, they offer the ideal environment to foster beneficial bacterial growth around the root zone, leading to naturally healthier plants. Extremely stable in both pH and EC Aquaponics are also ideal to be used in aquaponic systems Strong structural integrity means that they are less likely to break and compact, which helps to prevent dripper systems from getting blocked Pre-washed to aid in stability Aeration of growing media - ideal to mix into coco coir or soil to aid aeration Drainage will hold water as well as offering great aeration properties and free draining Decoration looks great as a top dressing for pots and also helps to prevent evaporation