Retain
Retain plant crystals are a safe and easy-to-use soil additive made out of water-absorbing ingredients (cross-linked polyacrylate, bentonite clay, lava rock, and silicates) that absorb up to 40x its own weight in water. 50 lbs of retain can hold up to 250 gallons of water. It increases the water-holding capacity of soil by up to 60%, helping to prevent waterlogging and releasing the water to plants, minimizing evaporation, especially in hanging baskets prone to drying out.