Don't do anything.... at least not yet. For 2 reasons, #1. What you're seeing as burnt tips on the newer growth may not actually be nute burn at this point. If it were I'd actually expect to see it on the tips of those fan leaves that are 1 node lower from the top as well. What you might actually be seeing at this stage is simply newer, slightly more pale growth in which case you have no issue whatsoever. I'd also be surprised if your nute regimen is too strong given that your using organic. N-P-K is about standard with other systems but my experience with Biobizz is that like most organic nutrient systems, they are somewhat less aggressive and potent than your typical synthetics. #2. If it is nute burn, it's very, very minor at this point which means your simply running the plant to it's nutritional limit and that's not really a bad thing. If growth rate is still unimpacted then odds are good the plant will simply grow in to your current nute mixture concentration. I'd probably keep the nute mix where it is for the next week or so and you should be fine. ***The other alternative is to simply stagger your feeds, 1 with regular water and the next with your nutes. Realistically, this is a 3 week old plant in a soil medium so it really doesn't need a whole lot more than what it's already got in the dirt until about week 4 or 5. Steady as she goes homie. Good luck with it.👍