Strange uniform spots on leaves...Have a LOOK!

[seedtick]

The pics are from an outdoor grow in amended soil (mix of FFOF, Mushroom compost, perilite, some builders sand, earthworm castings)straight in the ground. Been using Fox Farm Nuts at half strength at every other watering (Grow Big). I have tested the soil and it is Potassium deficient. Have watered once with Tiger bloom late last week. It is a little early to tell if it will make a difference. It seems to me there is another problem going on other than the potassium...almost looks like a fungus. Leaves are spotted and the lower largest leaves are turning yellow and dying. My guess it might be from to much water. Please help...any thoughts are welcome.

[Corto Malteze]

it's not overwatering for sure

look closely under the leaves if there are insects doing this. You should apply a pyrethrin based insecticide (harmless to plant but potent against bugs). Apply in evening or early morning.

It might also be powdery mildew due to humidity. Use baking soda or skimmed milk to raise the pH and kill the fungi (apply in foliar spray too).

You can also buy a fungi and insecticide all in one which should work too.

Good luck.

[Corto Malteze]

I think it's powdery mildew but I'm not sure:

If it's powdery mildew, you can use the following (found the dosage for ya):

Put 15% low fat milk (not reg.) 85% water and a drop or two of soap. Spray it on the plants every few days until you notice it's gone. Some strains are more susceptible to powdery mildew so if it's the case keep at it as a preventative measure. Mildew comes from lack of fresh air so I'm guessing they're indoor? You should air it out max and prevent humidity and heat.

OR

Neem once in a while can help against Pow. mil. (not often because of the burn with the sun/lights). Also helps against insects.

OR

10 % baking soda and water: raises pH so mildew dies. Use for 3 days, then wash leaves with plain water. Very known method.

OR

Garden sulfur spray (common and not toxic either against PM bacteria): use only in veg. and then stop before flowering so it wears off by harvest. If sprayed on buds, they will taste like sulfur.

OR

Serenade (brand).

You shouldn't smoke buds if they have powdery mildew (very bad for lungs) so careful with that.

[seedtick]

I have recently checked the PH and it is around 6.6-6.7. Is that enough to repel mildew? I have also checked for insects, but have not found any. It is an outdoor grow. Thanks.

[canuck420]

it is definatly not powdery mildew it is looks like insects to me u need to inspect your leaves and try to find a critter if possible, other than that it looks like thrips or whiteflys, good luck

[seedtick]

I have checked for insects carefully and have not found anything. Anyone else have any suggestions?