Zamaldelica ACE first indoor

The branches are growing but I had to push the screen down because the growth was not sufficient. New leaves are a bit more yellow-green . And spider mites are arriving ... The more i look at them, the more i think they don't grow... something is missing ? nitrogen ? At the end of that week, if they have not grow well, i will probably remove the screen because i don't see the point of starting flowering next week with so much holes ... If the spider mites are arriving it will be easier to remove plants and clean them outside the tent. I got rid of the spider mites (black soap and rinsing with water), I hope they don't come back too fast. The last 2 days of the week, the growth has been better and the yellowing is gone , maybe because i used diluted urine (1/10) for watering. Also I stopped the air extractor, the last 2 days, because i was getting very low humidity (between 20 and 60%) and I thought it might be a reason they were getting yellowish or dryish...? Now the leaves looks much better.