Another question..... On my transformer for my light there is three settings low med and high.... Should this be changed? It changes the intensity of the light. the brightness.... If yes when?That's
extremelypretty high for a 400-watt HID, IMHO. Are you trying to cover too large of an area with the one light?
Speaking of light... I hope that you've just brought those plants out from your grow area to where you took the pictures, for convenience, and that's not actually the grow area. If it IS, those walls are probably reflecting (at best), 45% of the light that hits them, at a guess - and placing some kind of flat material that you can prime/paint with bright white paint and use for wall coverings would help quite a bit, IMHO (I can understand not wishing to paint the log cabin(?) walls white; and a lot of light would get reflected upwards by the curves in any case).
Try 14" to 16" (and that's not exactly close...). The "auto-flowering" factor will help increase the DLI - since you're giving them 18(?) hours of light per day instead of the traditional 12 (which is a 50% increase, of course). However, if your light source is too distant, your plants are going to s-t-r-e-t-c-h towards it even if you increase it to 24 hours (constant on).