if you grow high-grade improperly and the THC levels and stuff go down, doesnt look,smell, and smoke as good, it would be lower quality/mids to me. so my opinion is genetics are definetly a huge factor but growing also makes difference in quality. for example pitbulls some try and beef them up, ham-bones for the jaw muscles,trying different foods for the best protein and stuff, some put them on weights and training. all to enhance and improve but that wont make the pitbull, its all bout the genetics. what the mom and dad looked like. where do these lower quality weeds come from?? bad high-grade growing??.... where does high-grade come from?? good lower-quality growing?? lol im stoned.