When Conophytums go dormant in the spring, they require little or no water. In the fall, when plants will begin growing, it is safe to water deeply, allowing the soil to dry before watering again. During active growth, if leaves start to wrinkle, your Conophytum needs water.
Hereof, why is my Lithops wrinkly?
The best way to tell if your Lithops need water during the time when it’s okay to water, is by observing them. They’ll start wrinkling or puckering, or maybe even appear to be sinking deeper into the pot. If you give them a gentle squeeze, they feel softer than when hydrated.