Posted: 25/08/2017 at 17:14
The lower leaves will start to go yellow as the season progresses, cut them off - the plant no longer needs them. I've removed about the lower 1/3 of leaves from all mine a few days ago.
the purple blotches are also typical and caused by environmental conditions, usually a chilly night after a warm day and it causes some apparent minor leaf damage (a chemical reaction inside the leaf goes a bit wrong). Nothing to worry about, just leave them.
If the leaves go curly - that's down to draughts and nothing to worry about either.
As you say, the plants are doing their stuff and producing well, so that means you're doing a good job. Just remove a few yellow leaves and carry on doing what you're doing