BioTabs users

Week 5 is considered from day 1 when the plant emerges from the soil. So it would be day 35 of the plants life. I wouldn't necessarily go by the plants age. You have to monitor your plants leaves and learn to read what they are telling you. Some plants might require the feed a week early and others might be fine for 2 weeks after the scheduled dose. When you notice the leaves lightening up or get any unusual discoloration then it is usually time for a feed. As far as your lights every manufacturer is different. During the veg phase I monitor the spacing between the nodes stacking up. If they are stacking right on top of each other then the light is too close. If you are getting a long stretch with several inches between each node then the light is too far. You kinda have to find the sweet spot for your particular light that gives you a nice medium node spacing with steady growth. Hope that helps and good luck with your grow!