Burn on tips seem like Nute burn.. if all else looks healthy like mine was then you don’t have to worry.. at first I thought they was aphids in my grow I read so much info on them I was ready to do two things nuke my plants with bad things (merit) or just cut them all down only problem is my plants was perfect nothing wrong and if they was aphids I was sure to see a problem in flower.. but never did! I thought it was so gross I hate any little bugs but mine turned out to be hypoasis miles which was only predator mites for fungus gnat larvae not sure how they even got into my room but it was a good thing... now if they start to fly the. You have aphids or if your plants take a turn for the worst and almost die then it’s aphids another quick way to check is let plants dry a little and put out from the pot and look at the roots if you see them bugs all over Roots and they are brown good chance it’s aphids.. if plants stay healthy no worries