I've never grown in anything less than a 5. And I use the vermiculite and a little soil in my coco because I don't know if I could handle watering more than once a day without stabbing myself. I haven't done an all soil, indoor grow in a super long time either because...coco. Once you go coco, it's hard to go back. I think I'll try an all soil auto grow outside this year though. I'm gonna take a break from indoor growing, an outdoor photos this summer. Indoor growing here, even inside just fucking sucks. And I need a break from photos.