leaf problems etc....so far no obvious answer

I'm helping a friend with their grow this year since I am unable to grow this year, and we are seeing problems we haven't seen before. Both of us have grows under our belt, we may not be experts but are relatively knowledgeable based on past experience and other issues in years past, and have been successful.

Everything is outdoors, 10 gallon pots using FF Ocean Forest. Feeding Grow Big and Big Bloom a few times a week Leaves are showing brown tips, necrotic spots and some yellowing in the bulk of the leaves, not the edges. First thing we did is stop feeding, thinking maybe it was a bit of nute burn. But after 10 days the problem is still there. It's not overwatering, they are watered in the morning and typically start to droop and the soil is dry late in the afternoon, normal from past experience in the summer heat. Only thing that is PH'ed is when nutes are given, since they tend to acidify the water. She's used the same tap water over the years, it's slightly alkaline but she's never had PH issues before with it.

They took the following pics to several hydro shops, and everyone is stumped as to what it could be. Different strains, and it's across the board, not specific to one

Here is a pic showing the yellowing, which has gotten more pronounced since the pic was taken



Attachment 2239083


Here is one showing the necrotic spots and some of what we see on the edges




And a few more









Other issue is whiteflies. She has sprayed Monterey garden Knock Down Garden spray (pyrytheum/canola oil based) once a week, and next day they are still full of the little fuckers. Tried Spinosad, same thing. yesterday she tried Neem oil, today, no shortage of whiteflies. There is a Praying mantis eggsack waiting to hatch, but we were told they can help control pests, they arent gonna get rid of the whitefly infestation. Plenty of the yellow whitefly traps around the plants, loaded with them but doesnt seem to knock down their numbers

So, looking for ideas primarily on the leaf issue, and then for the whiteflies. No other pests detected on close examination of the bottom of the leaves, pots are painted flat white so they dont get too hot. Help?

you got a soil ph probe mate? if not try and borrow one and see the reading. as for the white flies garlic tablets melted into warm water and sprayed normally will see them off. good luck fella.