Some leaves appear to have burned spots on it, som...

Hi @Thaithan! Well it's hard to make an accurate diagnosis based on your latest pictures, the pinkish grow light makes your pictures over-exposed, but it could be the very beggining of a Manganese deficiency. Since you're using soil as a medium, your pH should be within the 6.0-6.5 pH range, with a sweet spot around 6.2. Having the pH too high will make nutrient uptakes very hard, and this is especially true for Manganese which requires a slightly acidic pH (6.0~6.2). In this scenario I would increase the amount of BioGrow in the next feedings, your plants are no more babies and 1ml/L is very light, I would push to 2ml/L then 2.5ml/L after a few days if the plants are looking healthy. I would stick to a 6.2 pH range for the whole run, and trust the soil to do its job and buffer the rootzone whenever it's needed. I can also recommend to re-calibrate your pH-pen and EC-meter every 2 weeks, this will prevent any deficiency and ensure you the best quality in the end. Hope this will help, keep us up-to-date and happy growing! 👊