So Im going to be setting up a 20g community tank soon but Im a bit nervous. The thing that bothers me is diseases. I get all my fish from the same LFS and they told me that I do t have to worry about qt because they dont put sick fish on display or for sale. I have gotten 3 fish from there and plopped them in with my other established that has my betta and nothing happened. No disease outbreak at all. So do I still need to qt? Im really nervous.