Hello there. Need help with trichodiadema densum please. Started a small cacti/succulent garden a few months back. All are doing well except the TD. Have them in an extra large rectangular ceramic bonsai pot about 3.5 inches deep. Pot is in window sill facing west. Window has tint film so light is filtered. Used Hoffman's cactus succulent soil mix. The TD seemed to do ok initially but then the leaves began to wither. I attempted more research and guesstimated it was the soil, specifically, retaining too much moisture. Purchased some Bonsai Jack succulent and cactus soil gritty mix #111 and repotted the TD. Only been a few days so not yet sure if this is working. Wondering if I should stay with the 100% Bonsai Jack, 50/50 Bonsai Jack/Hoffman's or a different route altogether? Thank you.

Any of the cactus mixes mentioned will work just fine. What the TD couldn't handle was the extra moisture from living in a large communal pot (was it in the middle?). A couple days isn't nearly enough time to see how it will do. Hopefully, you aren't watering everytime you repot as that can lead to root rot.

Good advice.

I would avoid repotting the plant any time soon. Every time you bare root your plant, you cause it a great deal of stress.

How is the stem? Is it brown? Is it soft? Is the plant still firmly rooted? How much and how often are you watering?

The mix you're using looks good from pictures I've seen online. A few days is not long enough to judge anything, especially if the plant was already stressed. Give it some more time.

Regular window glass cuts a lot of the UV in sunlight, so indoor sun is actually already filtered without any need for tint film. I don't think the tint works to your advantage, actually. Sunlight through clear glass should be better.

Reply to 1st message: TD was in one of the corners.
Reply to 2nd message: Not sure I can do anything about tint film. Apartment complex applied it. From other research, said cacti/succulents should be 3ft from regular windows so I figured window sill was ok for these due to tint film. Stem is fine. Leaves just started to slowly wither at first, then it picked up. Plant still firmly rooted. Was watering based on what I had read. Let top layer of soil dry, then water thoroughly. Drainage holes in bottom of pot.

I'd let more than the top layer of soil get dry before I gave it water. That's me, but I've probably killed more plants over my lifetime by being too generous with the water than by doing anything else. I'm stingy with water even by the standards of the excellent advice available here on this forum, but I'm usually successful with my habits and generally have happy plants.

Your plants are beautiful, Donald. Yes, the soil on the surface will dry out first, sooner than the soil at depth, which is what matters. When in doubt, underwatering is usually tolerated much better than overwatering. A fast draining mix like the one you're using will help out a lot with the watering, making it harder to overwater.

The closer the better to any window, provided moderate temps and decent air flow. A windowsill is usually ideal, and that's what I use for some of my plants.