Brown tips on leaves

So, I am on my first grow, and just a few days ago I noticed tips of the older leaves turning a little brown. If you have any idea as to what it would be that would be great. Ill attach the pictures, and any suggestions or advise would be appreciated. Thanks!

nute i would say

but being that young hard to say ph can sometimes look like that

yeah usually just a ph problem i get bits like that on the leaves of a new plant.
i put it down to the plant finding its footing.