My hermit crab Toodee I've have for a year in July. When I first started out, I had her and 3 other crabs all crammed in a 10 gallon tank because, well, that was all I had. At the time I also didn't know I could use play sand, and the "hermit crab sand" was way too expensive to buy 6 inches of...so I the substrate was deep enough were they could just fully cover themselves. Then, a crab was showing molting signs and so I freaked out and put her in an ISO tank all by herself cause I didn't want the other crabs to eat her, I didn't know what I was doing. She attempted a surface molt and died

That's when I got the 20 gallon long tank, along with 4 new hermit crabs. Toodee as well as the 2 other crabs (including the one who successfully molted), all buried right away when I put them in. There was much more sand, better conditions, and more space. The one who successfully molted, died buried under the sand, I think she was trying to molt again. The other crab is still buried! It's been 4 months! There have been 4 other successful molts though since I got the new tank.
The problem:
Toodee though, she molted and came up too! Then switched shells. But she's been acting funny. She's been burying for a few days up to a week, then comes back up for a day or two before she goes back down. And her skin looks bright bright red and her face looks a little pale. She looks fragile and weak, but she's climbing the fish net and cholla and walking around. Her legs look like they grew no hair...and I thought after a molt their legs get super hairy.
Here's some pics of her:



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What do you guys think? I can't spare another death, I'm really trying my best.