Yellowing leafs and dying tips

Hey Pisolo, Don't worry. It's very common and caused by either too little or too much nutrients. the tips of leaves turning will likely clear up in a week or so. If it is concerning you. My advice would be flush for a few days then reintroduce a higher dose of nutrients and see what happens if you get burnt tips again then you know its too much rather than too little then flush again for a few days and then re adjust nute levels lower and you should be alright. Though drastic temperature changes can also cause this along with other environmental factors. Though personally its probably an underfeed. I try and gauges a feed I give a certain plant on the size of the plant larger plants can take a higher EC and in flowering they can take alot of nutrients so you can up the feed. This is all just my opinion with my experience,