There's a good chance of recovery from ich if you eliminate or at least try to reduce stressors. But you put it in a 12 gallon tank, which is going to stress it even more, I think.
It's a small tank. You have too many inhabitants in there. They'll start competing for territory and fighting... Especially if one is sick, weak, or hungry.
I noticed that you took the hood off and upgraded lights. I am looking to do something similar with my aquapod 24. What kind of lights are you running?