health Yellow Spots on Leaves- Not Mites

[bullmama]

My plants seem to be doing okay considering it is 110 F out side and I have a gnat infestation.  It's dry and hot is Arizona, my plants are in pots in my greenhouse, I figure conditions may help diagnose the problem.  My logical side says the gnats are due to too much moisture, since my plants are watered daily and have a cool mist on them during the day (none of the mist builds up on the leaves).
 
But these yellow spots are certainly bothering me, and I've searched and googled but could not come up with an answer.  Most of the plants are thriving even with the spots, but a couple are losing a lot of leaves.  It is the gnats?  Is it bacteria?  I know it is not mites as I am very familiar with them, so I have no idea, please help!
 

 

[juanitos]

In the case of magnesium deficiency the symptoms generally start with mottled chlorotic areas developing in the interveinal tissue. The interveinal laminae tissue tends to expand proportionately more than the other leaf tissues, producing a raised puckered surface, with the top of the puckers progressively going from chlorotic to necrotic tissue.
 
get some epsom salt or calmag

 

[twiasp]

Are you watering when it is sunny outside? Kinda looks like little burn marks.  I'm new to growing as this is my first year, just trying to help brainstorm.

 

[Wicked Mike]

Little brown spots with a yellow halo - bacterial spot. This is generally something that crops up in hot, humid conditions. Whenever possible, you want to avoid getting water on the leaves. Same goes for most Solanaceae, in fact.

Could be Magnesium as well. A little CalMag or Epsom salts as a foliar wouldn't be a terrible idea.

 

[Spicy Mushroom]

get some epsom salt or calmag

 
Could one mix say Epsom Salt and Tums for a cheaper (albeit less effective) solution? Could that be used as a foliar spray?

 

[bullmama]

In the case of magnesium deficiency the symptoms generally start with mottled chlorotic areas developing in the interveinal tissue. The interveinal laminae tissue tends to expand proportionately more than the other leaf tissues, producing a raised puckered surface, with the top of the puckers progressively going from chlorotic to necrotic tissue.
 
get some epsom salt or calmag

 

Thanks for the advice!  I have some epsom salt, what is the ratio to put on my plants? Should I put in a spray bottle or directly in the soil/pot?
 

Are you watering when it is sunny outside? Kinda looks like little burn marks.  I'm new to growing as this is my first year, just trying to help brainstorm.

Thanks for the reply!  I don't, but good idea because it does look like this.  I water early and I don't water the leaves, just at the soil.
 

Little brown spots with a yellow halo - bacterial spot. This is generally something that crops up in hot, humid conditions. Whenever possible, you want to avoid getting water on the leaves. Same goes for most Solanaceae, in fact.

Could be Magnesium as well. A little CalMag or Epsom salts as a foliar wouldn't be a terrible idea.

I think you are right since it's hot plus I have a mister going so it stays humid.  Should I prune these leaves or wait for them to yellow and drop?