You mentioned flies...did they jump out when watering? If so there springtails and are your friends, also turn your light off when spraying!! Those lower leaves may be get burnt, ive noticed your stems are purple, not sure if it's the strain yet that's a sign off humidity which should be around 55/65% at this stage, temps should be no lower then 18°C, magnesium deficiency, light exposure or in correct pH, Coco is 5.7/6.2 and soil is 6.2/6.5, overall she looks great for a first grow
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