A few whoopsies damaging a few of the leaves, and, what looks like possible nutrient burn (but only very slight), which is supported by the fact that the EC went up as the water went down. Have added fresh water without nutrients, and shall keep observing.
Main concern is that it should already be in flower, but is still vegging (and still very short) which wouldn't worry me if it was a photoperiod. If I could find something that was pretty much exactly the same, but a photoperiod, I would be growing that regularly.