My hermies are having a bit of a complicated few weeks, so please bear with me with my explanation.
A few weeks ago, my 29G randomly flooded (cause still undetermined), and developed a pretty substantial bacterial bloom. During my excavation/cleaning of the 29G outside, the glass shattered when I accidentally hit the tank against a nail on my deck. Additionally, I am also in the process of moving into my new home, in which the hermies will be upgraded into a new 40G. With these factors considered, I now have them in a spare 20G long for another week until I can permanently relocate them into the new tank. I know its not ideal since there are five (size small) of them, but its unfortunately the best I can do during this awkward transition period.
I feel that it is important to note here that all of my hermits have recently molted, and are still sporting shiny eyes and fresh toe nails.
Things have been fine until last night. I came home and found a large pincher and a leg piled in a corner. My first thought was that one of my PPs decided to randomly surface molt. Upon further inspection, it was Kermie who was missing both limbs. I'm not sure if Kermie (who I've had for over a year) is stressed due to the change in tank and decided to drop two limbs, or if there was a crab scuffle. I'm inclined to believe it was the latter, since the limbs appeared to have been chopped off - the entire limb was not intact like you'd normally see when a stressed crab drops a leg. However, my hermits have been housed together for over a year (except for the new addition, who is 1/3 the size of Kermie) and they've never been this aggressive with each other. They are fed well (I feed them better than I feed myself

I now have Kermie in a little iso tank of his own. He's been provided with salt water, shelter, darkness, and proteins. He surprisingly appears quite active given his condition, though he was lethargic last night. Last I checked, which was an hour before making this post, he was munching enthusiastically on honey covered meal worms and crickets. Bless his little heart. I'm hesitant to move him back into the 20G until I am able to get them into their new home. Is there anything else I can do to help him recover?
Below is the emergency template based off of my 29G. I added info in red as it pertains to the current 20G, but for the most part, the conditions remain the same.
Here's the template:
1. What kind of substrate is used in your tank and how deep is it?
Play sand, about 8 inches
The 20G has about 3 inches, making it lighter and easier to transport.
2. Do you have gauges in the tank to measure temperature and humidity? If so, where are they located and what temperature and humidity do they usually read?
The gauges are located in the middle of the tank. Temperature and humidity are usually between 80-85.
same
3. Is a heat source used in the tank? If so, what?
I have a UTH on the back on the tank.
same
4. What types of water are available (fresh or salt) and how is the water treated (what brands of dechlorinator or salt mix and what ratio is used to mix it)?
Both water sources are available. Instant Ocean is used to create salt water. Prime is used as the dechlorinator.
same
5. What kinds of food do you feed and how often is it replaced?
They get dehydrated fish, fresh veggies, fresh or dehydrated fruits, crushed eggshells, eggs, dehydrated insects, chicken, ect.
same
6. How long have you had the crab and what species is it, if known?
I have 5 - 2 Es and 3 PPs. I've had all but 1 for over a year now.
same
7. Has your crab molted, and how long ago did it happen?
They all molt regularly, and all have resurfaced within the last month.
same
8. What type of housing are the crabs kept in, what size is it and what kind of lid is on the housing?
They are in a 29G. The lid is plexiglass.
Currently in a 20G long. Lid is still plexiglass
9. How many crabs are in the tank and about how large are they?
5 in total - they are all small, some smaller than others. Two bordering on medium
same
10. How many extra shells are usually kept in the tank, if any?
More than I can count.
same
11. Have there been any fumes or chemicals near the crabitat recently?
Negative.
same
12. How often do you clean the tank and how?
Only to remove surface debris.
same
13. Are sponges used in the water dish? If so, how are they cleaned?
Negative.
same
14. Has anything new been added to your crabitat recently?
Negative.
I've kept basically the same set up as the 29G
Thanks for any input you can provide.