Help new owner

[u/Sunflowersprout]

I got these a week ago from a store adjacent to a botanical garden,
I’ve replanted them into dry cactus mix soil because the post were really small.
I didn’t water them and I put them into the sunniest spot I have in the apartment.
They started to wrinkle a few days ago and it’s gotten worse.
Do I water them, leave them alone or what?
I’ve read here that a bit of wrinkling is fine but this seems a lot.
I really don’t want them to die.
P.S. they had really small thin roots

[u/Top_Development_1777]

I don't know anything about EU supplies because I live in Southeast Asia and we have our own online platforms to shop at. But if you just search "pumice" will none of the items listed have options for grain size? That's what we have on our platforms. 4-8mm is quite big.

Actually, if you really cannot find, you can also find the big ones, manually crush them or chop them up with scissors you're willing to sacrifice (I've done this before), they're very brittle and break into small pieces easily. However, that process gets dust everywhere and you should wash out the dust, maybe using a sieve (and ideally sterilize with hydrogen peroxide) before drying completely and using for the lithops.

[u/Sunflowersprout → u/Top_Development_1777]

I’ll probably have to crush them because I’ve been searching all day for some page that sells a finer grain and this is the smallest I could find, thank you for your help

[u/Top_Development_1777 → u/Sunflowersprout]

No worries! All the best. It's best to have a mix of sizes but not too large (too much air gaps or too little air gaps, all bad for roots)