Number 1 mistake by far is planning a dream grow with thousands of watts of light and 10 pound weekly harvests, joining a forum to learn how other people are doing it before they start, reading for 2-3 days & then start giving advice based on the killer results they get from the grow they havent yet started, give shitty advice to the newbies who actually do have a grow going, get upset when they get called out on their bullshit and turn into vaginas and call the mods because theyre getting picked on. Criminals dont call the police, everybody likes pussy but nobody likes a vagina. That and thinking they can start a grow without all the stuff to finish it, if you can only afford a MH bulb right now and think ul be able to afford the HPS and carbon filter when you flip to flower your wrong, if you think u can make it this one time without a carbon filter because youre only growing 4 plants, your wrong, & all the other stuff that was already said