Yellowing leafs

It looks ok to me they are just some old leaves dying off normally with biobiz you won't know it burns till about a few days time when the food breaks down a bit. Could also be a bit of overwatering. But I hope you get it resolved good luck happy growing

Damage from hitting the edge of the pot, nothing to worry about. Next time, try and always post pictures taken in "normal" white light, blurple grow lights make it almost impossible to see anything properly.

In my opinion you are giving them too little light. It‘s pretty dark in the oicture but the spektrum if your light is way too monochrome. It‘s basically lack of photosynthesis in my opinion.

i see water drops on other leaves, did you hit when watering? Or your humidity is way too high if its through condensation.

This is difficult to answer without a diary. All we have is a picture under a blurple light. Fill in as much of the details as possible. I'd say needs maybe more food or calmag. You'll need measuring equipment for pH and EC along with rh and temp and set up. What lights fans , soil or Coco. Age of plant lamp distance and many more. Help us to help you