u/Chemical_Ad9238

A few days ago one of my crabs came up from molting with only 2 left walking legs, im not exactly sure what happened to him. I've since set up a isolation tank and besides the missing legs he is doing alright, as active as he can be without being able to walk and is responsive to me hand feeding him fine foods I've mixed with water. My main question is when should I put him back in the main tank/how far along do his leg regrowths need to be for it to be alright? When his claws are back and he is able to feed himself is that when I should reintroduce?