Leaves turning black? Fungus gnats? Aphids? Help please!

Here is a pic of a leaf I was talking about although this is not the best picture.

Extacie said:

ratio of 3.2-6.4 oz./100gallons for light infestation. I've read online 4-8 tsp/gallon for heavy infestations?

My questions: •How many tsp/gallon?

I wish the directions were a little more help!!!

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The manufacturer is making the incorrect assumption that you can do basic mathematics.

If you want 3.2 oz/100 gallons that would be .032 oz per gallon. Converted to teaspoons that is 0.192 teaspoons. Good luck.

View attachment 2935366 Here is a pic of a leaf I was talking about although this is not the best picture.

Bump? Just want to make sure it's not part of the molding issue so I know if I should remove the whole leaf or not? Thanks, + rep to whoever answers!

It looks more like a deficiency than mold to me but I am not certain. There are others who will have a better idea. What kind of nutrients are you feeding them?
I would trim anything brown off and leave anything green.

If you want to go into your grow room during lights off use a green light. The plants cannot see the green light spectrum. I just use the flashlight app on my phone, it allows me to choose a color for the main screen.