I broke mine off live when they were around 3-4 inches. It took about 2 weeks. They went a long time without food. I think they're pretty hardy at that size as long as the water is super clean. They are very sensitive to poor water conditions. I found that the larger the tank I had them in the less sensitive they were since the volume was bigger. When they were 2 inches I had them in a 30g and had to change water almost every 3 days.
