Holes in leaf

did type a massive post but paged refreshed haha I have noticed some holes just affecting this one leaf strange never seen it or had it before I will admit I didn't ph water on transplant I know it's around 7.2 on inspection when I replace batteries in my ph pen just hoping it's not pests I haven't seen any plus it's just on this one leaf
Soil bat mix plagron
600watt hps
Temps 26-28
Humidity 35-40
Strain great white shark 3 weeks from seed
I was misting them could this be why maybe it acted as a magnifying glass
Other strains are grapefruit sour diesel jack herer and ak47

 

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Here is some pictures

 

Thanks for your reply I'm start to think it's where I couldn't find my mister and I just put my hand in the water and flicked it on the leaves well I'm hoping that I've got my magnolias and gonna check now

 

Have now just finished properly inspecting each leaf and soil and there is no signs of bugs of any sort so my only explaination which I can come up with is either ph but then wouldn't other leafs have the same problem or where I left droplets of water on the leaf I hope someone can come up with and explanation other wise it may get the boot or left to grow outside

 

If problem seems to worsen I will indeed give it ago I'll order some now just in case thanks for your input very much appreciated