What could cause the yellow tip? It’s only that leave. I watered before I left town for 2 1/2 days. I could of messed up the PH because it was like 3am on my way out the door to catch a plane. But not sure. I don’t see bugs. The white stuff is DE dust and not part of issue
it could be a variety of things honestly but if its not affecting anything other than the one tip don't do a thing. If it starts getting worse or spreading to other parts of your plant then you will need to look deeper into it but your good for now. Hell it may be as simple
as too much water or humidity(or vice versa *ie:not enough) I run soil but I honestly don't worry alot about ph because I don't add anything to them. Other than say compost manure and maybe a houseplant feed stick during veg.
nothing to worry on, add nitrogen to your mix, if it bothers you cut the leaf off, you are growing for the bud not that bottom leaves, cannabis can take a lot. your plant looks normal and healthy. , you doing just fine