Not necessarily. What you have to do is set up a 5 gallon (or more) tank that's betta only. Go online (Aquarium Co-op has the best service) and get some medication to prevent infection. If you don't know which med to buy, Candi (or someone there) can help you, they're unbelievable! You can instantly cycle the 5 gallon with the filter media from the other tank. The best thing I've ever done is to nab 5 gallon aquarium kits when they were on sale at PetSmart for $30 each! I always have a spare tank for a crisis. And there's always going to be a crisis. KG Tropicals has a video on YouTube called "Bubbles." Bubbles is their blind betta; one of their cichlid videos introduces us to "One Eyed Willie," a cichlid that lost an eye to his tank mates but was just fine.