I have 5 in mine the front two seem to grow best. the ones in back seem to be a bit slower growing. 5 is fine, unless they are feminized, you will probably pull out at least 2 males
these pics are of 3 week old auto flowering plants that will not grow very big. If you have tall strains 5 flowering plants definately be rough
I say 2-3 plants. I started with 3. Ended with 2 females. No matter what your plants will get big. Remember that. Heres just one plant, I topped and everything. Had to pull him cuz he was a male.