Hi. I have a couple of train wreck autos in week 5 that the bottom leaves ( some of them) are turning yellow. The stems and some of the stalks are red. They are in the stretch( I think) as they are starting to flower and are growing about 1/2 inch a day. Should I be concerned. No nutes or calmag or ph tests yet. Ph meter coming this week. Not really sure if I have a problem or not. Thanx. OF