Diagnosis For Silver Marks On Leaves?

[Callmebuddy]

Hello everyone, I have run into a problem and hope to end it before it begins to damage the plant. A friend of mine planted a seed he found in his bud a while back, not expecting much to happen. Now, it's three feet tall and in its very early stages of flowering. However, a problem came up... Some leaves are beginning to whither and small, irregularly shaped silver marks are appearing on the surface of the leaves. The mark does not go from one side of the leaf to the other, they are only on the surface. More and more of these marks are showing up as the days go by. He has noticed little flies which he believes are fungus gnats in the soil. Though, he hasn't found fungus gnats as the cause for silver marks on leaves-it is mainly due to thrips. Based on the pictures and description, what do you all think?

 

[cocoJoe]

I do not see thrips..
Maybe some nutes got splashed on to the leaves??

 

[Callmebuddy]

I do not see thrips..
Maybe some nutes got splashed on to the leaves??

That's definitely a possibility, however some leaves are beginning to whither and brown on the tips. I haven't been able to find any bugs on the leaves so far, so I do not have any pictures. Here is a picture of a couple browning leaves and a wither one:

 

[snippetysnip]

Hi mate, I've just dealt with thrips and the silvery marks that were on my leaves didn't look like your ones.. they were more like snail trails than anything..
Callmebuddy" may be on the right track with the nute splash? I've attached a pic of my silvery thrip damage.. zoom in...
Good luck!

 

[snippetysnip]

Excuse me I meant "cocoJoe" ...

 

[Callmebuddy]

I'm definitely now leaning away from bugs and more towards the nutrients. The plant is in Miracle Grow potting soil (I know that's BIG no go now, but didn't earlier). I've read that Miracle Grow has "extended release" nutrients. I also know it contains a hefty amount of Nitrogen. This amount of Nitrogen is fine in the vegetative stage, but is way too much in the flowering stage. Do you all believe this, or something closely related, may be the cause?