Also what is the smallest tank you can get for them? And what do you need to put in the tank to make it cycle properly? Sorry for all the questions but I want to make sure everything is good this time around.
The 24 gallon nanocube, or 29 biocube would be suitable. I would take out the actinic light and replace it with a 10k or not replace it at all. You would also have to close off any cracks between the main tank and the back that houses all the filteration.
I kept a dwarf in a 10 gallon for a couple of weeks, and it seemed very unhappy. Of course it was moved from a 75 gallon, but in the 75 gallon, it was also contained in a critter keeper but still was much happier than in the 10 gallon. If you go this route, you might try adding a tiny peaceful fish. Mine seemed to enjoy watching the fish swim around it.