From what I hear... It is ready to use out of the bag for some species like snakes and Geckos... I tried incubating a clutch of Veiled Chameleons a year or so ago in Hatchrite... And lost the entire clutch to drying out and sinking in. Everyone I know who uses them with chameleon eggs has to add water, as the Hatchrite itself just doesn't provide enough moisture. Seeing as how I lost a whole clutch by following the directions on the bag... I will no longer use it. That, and Vermiculite is just soooooo much more affordable. It takes all of 5 mins to mix the water in, and the extra $ you pay for a small bag of Hatchrite just doesn't seem worth it IMO. It's like $14 I believe for a 2lb bag of HR... I bought a 20 lb bag of Vermiculite at home depot for $25 and will have enough to last a lifetime.