Purple Punch Auto Barney's Farm

the growth continues well, in a few days I will set the new 480 watt led light and I hope to get a luxuriant growth. it seems to me that the tips of the leaves have a very dark color, it looks like an excess of nitrogen but in three weeks I have never fertilized and the only additions to my biobizz light mix are a sprinkling of guano kalong and 10% of worm humus biobizz.