This could lead to iron deficiency for your Crassula Moonglow plant. In order to ensure healthy roots and normal growth, the Crassula Moonglow needs soil that is well-aerated. Because the Crassula Moonglow originates from a cross between two cactus species that are used to very hot conditions, it, too, likes heat. I recommend using equal parts perlite and the cactus blend if you live near a humid area. It is also a good idea to soak the roots in an antifungal solution before you put them back. You should keep this plant out of reach of cats and humans as it is toxic.