does anyone have any idea what may be causing the tips of my plants leaves to curl down,they aint discoloured or damaged in any way,or could it be because it's flowering?any advice will be much appreciated thanks
possibly mineral salt lock-out? I have had that, and currently have it now. You can't fix the leaves that have turned or cup-curled, but with a flush, new growth should be okay. It doesn't seem to affect over-all results, as long as you don't let it go. Also, low humidity in the room can make the problem worse. my humidity is between 30 and 40% with the majority of the time around 35%. I use big cfls and my high temp is about 82degrees fehrenheit, so I know it isn't heat stress.