Nutrient problems??

the burnt tips looks like nute burn from overfeeding phosphorus and potassium. the tip of the leaf clawing down like that and your leaves being dark green(kinda hard to see the exact color under the purple lighting) are signs of nitrogen toxicity. So overall it seems like you are overfeeding a bit too much. Nothing is horrible at this point and a little nute burn isn't anything to worry about, but it is telling you that you have gone a little past optimal nutrient levels in your feedings. So I would back off on your nutrient doses a little bit, like maybe 10% or so. You should also flush things out with plain phed water to reset the grow media and get rid of any extra nutes. once flushed I would feed at the lower dosage the next time you would normally water them, and then continue watering as you were previously but at the lower nutrient dosage. If you still experience these issues getting worse repeat the steps above but back off even further off the nutes. for reference, all of my plants have slight nute burn due to me slowly ramping up my nutes as they flower. I always increase little by little(I use dry nutes and measure by weight and use an EC meter) until I get the very first sign of nute burn and then back off to the amount I was feeding the previous feeding that didn't burn them. this allows me to find out how much the max amount i can feed them is for the best growth. I hope this helps and if you need any more assistance feel free to dm me!