I've mixed thoughts refferacing the inner and outer ceramic glazing of the coffee cup. they work but drilled drainage " holes on the bottom " may need to be increased ? or more. It's a bit wet now and entire plant and roots should come out easy for you, set the entire soil and plant on news paper with news paper on a tray allowing some dry time ( over night) as you prep the looser (airy) suggested soil. Watering may take time for you ( climate area, air ect..) to get use to. Size of it and seeming that you might want to to but will ask Are you indoor window sill growing all season ?

well there are plenty of threads on the forum regarding 'the gritty mix' , just put it in the search bar :) If you're looking for a quick temporary fix dunk a whole lot of perlite into the soil...maybe 50/50 ratio. As for the sand, it tends to 'compact' when wet (bad aeration) so it's generally a less popular choice in growing medium. Hope that helps, and goodluck with saving your plant :)

It is best to take off as much of old soil as possible - leaving it defeats the purpose of using different mix - at least to some extent. It is recommended to add 'generous amount of perlite, 50% or more' - I think you did well :) You could grow succulents in pure perlite, or pure pumice, or pure grit (or some other inorganics) - they all provide good drainage and aeration. Some bags of perlite have lots of dusty fines, so it may be good idea to sift it. I use a kitchen sieve to do that, putting all sifted perlite into a container with warm water (most likely it doesn't have to be warm, just the way I do it) and rinse it. Then I strain water using same sieve and use it. If I was to use the mix you mentioned, I would sift it too; most often there is still lots of fines in the mix. You should check if there is list of ingredients on the bag to see what it contain. Too much of organic ingredients may attract bugs like fungus gnats since they like wet organics. Not saying you shouldn't use it thou :) Many ppl. use this mix, just have to be careful about watering (that's why addition of perlite-to make drainage better). Personally, I don't buy it since I don't really see any benefit using it for succulents.

I am not sure what is wrong with them and would hope someone smarter than I will come along and help out. Not sure if it's a disease or growing conditions not right. But I will tell you that these plants need a fast draining potting mix, and commercial cactus and succulent mixes are most often too water retaining. Remember these are succulents, they hold a lot of water in their leaves and suffer if they are overwatered or in soil that holds the water too long or even dries out and resists water. The best practice with succulents is to have a fast draining soil, and when the plants are dry, water until the water comes out the bottom of the pot. If you want to try to save them I would suggest mixing your cactus and succulent mix 50-50 with either perlite or pumice available at nurseries here, not sure what's available for you there. Both pots need to have holes in the bottom so you would want to replace the one without a hole. If you do a repot and notice rotting stems, the plant probably won't make it.