Please help!!! Is this mold? or bacteria?

My girls are about 4 weeks into flower and now this. I am using the foxfarm line. This happened after kicking em with open seseme.
They look burned to me but I am hoping that you peeps can help me out here.
Anyone have an ideas? Could this be mold or some sort of bacteria? What do I do?
Thanks for helping guys.

Just wanted to add some more info about my grow.
I was told by an old time grower that to help dense up the buds that the temp difference from lights on to lights off should be 10 to 15 degrees difference. I have since read that unstable temps between lights on and lights off can cause serious stress to plants. I have been running AC to keep the room in the high 60's to low 70's.
Could ths have caused my problems?

what regimen are you running? nute burn begins at the tips and works its way up, it looks like that's what you have.
that temp differences isn't the issue

Thanks for the reply man. I should have stated the strain as well. This is AK-47. I have heard that the Kush strains are more sensitive to over nutes. I hope that it is just nute burn.
What should I do for them? Last two feeds was just straigt water PH'd to 6.5
Should I continue this for a few?

upthearsenal said:

what regimen are you running? nute burn begins at the tips and works its way up, it looks like that's what you have.
that temp differences isn't the issue

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Forgot, I am using the foxfarm line in Aurora soil.

check this link out https://www.rollitup.org/marijuana-plant-problems/216537-self-diagnose-your-plants.html. Looks like a phosphorus def or a potassium def.

G37Kush said:

check this link out https://www.rollitup.org/marijuana-plant-problems/216537-self-diagnose-your-plants.html. Looks like a phosphorus def or a potassium def.

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This is great info. But just one thing. If what is happening is in fact nute burn then hitting them with a dose of phos or potassium might make the problem worse right? Should I use straight water for a couple more waterings or should I hit'em with a dose of Phosphorus?

you could flush, give it a week, and then decide whether you want to feed her PK