I recommend using neem oil it gets rid of powdery mildew good, But if your going to harvest in 2 weeks or less you shouldn't use this because its been known to leave a neem oil taste in the buds if the plant was sprayed 2 weeks or earlier before harvest , but if your not going to harvest in 2...
Your plant looks good, the yellowing of the bottom leaves are normal but you should give your plant a slight dosage of nitrogen because your plant looks light in color.
Well the leaves that are turning yelow and dying is usually normal in a plants life but it looks like you have a nitrogen deficiency though witch is not really a big problem just give it some Miracle grow blue powder stuff in your waterings and that should have enough nitrogen to give to your...
NO DO NOT TRANSPLANT YOUR PLANTS INTO MG SOIL THAT IS THE WORST IDEA, try to get Kellogs outdoor patio plus potting soil from lowes or home depot.
It looks like your plants have a phosphorus deficiency.
"BL0TT0
Are you growing 2 plants per bucket?
If so, that's yer problem. If not...I...
The bud worms only seem to damage just that one little bud part of the nugs as long as you kill the worm the rest of the plant should be fine and bud worms dont travel that far either witch I have seen from personal experience.
Open the top of the bud that is rotted away and see if you can find a little worm in the stem, if you do just squeez the stem to try to kill it or you can stick a needle in the stem to also try to kill the burrowing insect.
You could also have a potassium deficiency because the leafs were crumbling up and dying and looked like it had some brown rusty color spots on one of the leaves witch would mean you have a potassium deficiency.
That almost looks like you have beattle bores try to see if you can find a hole that looks like it is covered in saw dust if you do try spliting open the stem just slightly and you might find a red orange like worm inside, the only way I know how to get rid of beattle bores is to put a needle up...