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.

What Makes Retain Different Than Other Water Retention Crystals: In a word... speed. Most water retention beads/crystals soak up water very quickly. You can watch them puff up quickly as they absorb water. They are also unacceptably fast in letting go of the water. Retain takes it sweet time soaking up water, and correspondingly, is very slow to let it go... providing more water, longer, for roots, not evaporation.