

Help reading my cactus?
I've killed one cactus I bought when good ole Walmart had their big restock, and am so nervous to kill the ones I actually like. The tephro is especially hard for me to interpret since searching says wrinkles is due to both over and under watering.
Any tips on cues from these two would be great! Both are in miraclegro cactus mix with perlite added in. I have a 3200 lumen shop light like 2-3 feet above them, and they are in an upstairs south-facing window that doesn't get any shade.
Thank you!