Thanks all for your responses, I have done some reading around and have found it’s normal for those leaves to go yellow first then brown and eventually fall off.
I really couldn’t figure out what I had done wrong. I haven’t watered her in a week so I thought it couldn’t of been a over feed, although it could of been a under feed so I gave her juice today.
Can’t be PH as i test it and give 5.8- 6.0.
Lights well I have LED 45w on 18/6.
Temp is 20/21 in the night, 23/26 in the day.
Humidity I have a problem with as I grow in a pc case so It’s up and down but always a flow of fresh air in and out using pc fans but still not convinced was the issue.
Nutrients, well with igrowcan its comes with its first set of nutes that are mixed from the start into the soil and the bloom is fed with flowering.