Hi— I have had this cactus (though careful online searching, I believe it is a "Echinopsis pachanoi f. cristata" or a "Crested San Pedro Cactus" for nearly 2 years. About 4 months ago, he (Apollo) began to develop this crusty white material on his side? It has now spread. He is also leaning quite a bit. I have no idea what is going on— have been caring for a and watering as normal— and I have not changed sunlight. Any help appreciated! If I lose this guy I will be heartbroken!
As I write this, I realize that I repotted him in July, which was shortly before this appeared. Could this have had anything to do with it? Is there anything I can do now?