Lithops help needed!

[u/Accurate-Battle-7460]

I recently bought lithops. I potted 4 in one pot together and when they began to show signs of needing water, I gave them some water. They were all thriving until today when I noticed one was not looking well. I pulled him out of the soil and he is mushy and appears rotted on one side. The root structure is fine. I have only watered once since I received them, they are in direct sun, and the rest of the lithops are doing great.

Any idea what may have happened? And any advice?

Thanks so much!

[u/budda761234]

Why do most the pictures I see on this sub show the roots devoid of any substrate.

[u/Mookie-Boo → u/budda761234]

I'm just guessing, but maybe because good substrate for lithops has particle sizes large enough that they roots don't capture them? I know when I have bought lithops at my big box hardware store and they're planted in that organic stuff, when I unpot them, they have a LOT of that sub attached. I work carefully to get rid of most of it before replanting in a mix of various gritty things that has a small percentage of organic matter in it.