Discus from a LFS can be hit or miss. Most of the time they should have been culls, every once in a while you'll find a decent one. I always had trouble keeping discus I bought at the LFS, They would do fine for a while and then just die for no apparent reason. I finally found a local breeder and bought some from him and never had an unexplained death again. If you really want to try discus you should try and find a local breeder or pay a bit extra and buy them online. It may cost more in the begining, but you know exactly what your getting.