Yellow tips on newer leaves

My guess you have Zinc (Zn) or Iron (Fe) deficiency

Lower EC

It looks like you are overfeeding the plant because of how dark green your leaves are and the burning starting to happen. In particular, it looks like too much Nitrogen. Cut back on nitrogen during bloom. Your plant does not need high amounts of it. This will likely cause excess leaf production as well rather than more bud production. I suggest you run a batch of just pure water pH balanced as your next watering and allow for nearly 1/4 - 1/2 the water to run out the bottom. This will flush out any extra salts that may have accumulated thus far. Hope this helps.

It's mild burn. Nothing drastic. If it's not spreading/getting worse you can likely skate by with no big issues but you could probably lower your concentration a little bit. Don't over compensate and starve your plant though.

Way too much feeding.