Plant looks healthy! I think you should upgrade the pot size if you can and lower your lights cut down on stretching and help her bush out a bit.
Good luck!
Hello mate.
Don't get me wrong I am a coming to you in a friendly way to help.
Have been wondering why your plants are not bushy or why the leaves are looking sick?
Coco coir is hydroponic.
Your watering routine is not meant for coco, same for your nutrients.
You need nutrients for coco, or for hydro. Organic nutrients cannot be processed by the coco as it is inert. Luckily to you Greenhouse bio nutes have some water soluble nutrients in it's mix but only in small amount. This explains why your plants are starving but are still alive.
A good place to start is cocoforcannabis.com or growweedeasy.
I would definitely check your feeding, the brown patches are calcium deficiency you need to add some call mag, I recommend by foliar spray for faster uptake!! Again good luck!!