After a few years of growing the succulent, you will likely lose some leaves. Did this post help you figure out what's happening with your succulent leaves? It is paramount to wait for the soil to dry out so that you can water it again. The Ariocarpus should be watered only when it is completely dried. Ariocarpus need to be grown in the soil only specified for cacti. This succulent needs plenty of sun. They require little water and a full sun or light shade. In such cases, a shade cloth would be of benefit or even moving the plants from the sun in the hottest hours during the day.