Struggling with Moon Cactus — would appreciate advice

I want to be honest: I'm not getting great results with Moon Cactus and I'm not entirely sure why. scarring from cold water splash on the skin has been a recurring problem despite my attempts to address it. I've been focusing on using pure mineral grit for drainage in the soil mix based on everything I've read.

extremely long-lived with minimal intervention is there in glimpses, which tells me the plant has potential in my conditions. I have it in an outdoor container brought in for winter which might not be ideal. rapid growth during the warm summer months showed some improvement. Two stars for now — not the plant's fault, but not a success yet. I'll update if things improve.