odd spots only on two leaves of the plant, please help.

Hey guys, so this is odd to me, i have 9 plants in a 4x8 tent, they are all doing excellent except for the one im confused about. as you can see with the pictures below the spots that are showing are only on two leaves, they are not consistent throughout the plant and dont exist on any other plant in the tent.
Setup:
4x8 grow tent
3x p450 platnium led grow lights
Fox farms: ocean forest mix with 25% perlite added
Smart pot: 10 gallon smart pots(transplanted 4 days ago)
Running 20/4 for the light cycle
Temps have been regular at 80-82 although humidity is usually around 45-50%
Plants are 31 days old from seed.
i have been watering about every 4-5 days with 1 gallon of RO water Phed down to 6.4-6.5
Because they are in fox farms no additional liquid nutrients have been added yet.
i did make the mistake of watering them with tap water the first couple weeks of their life. it wasnt until a week ago i realized my tap water has 320 ppm in it(without anything added) i stopped using that immediately.
Strain: Strawberry Kush
I have not noticed any bugs in the tent or in my house. and i have looked intensively.

What is causing these spots? and what should i do? it does not seem to be hindering growth at all. they are growing like crazy and even after topping them twice so far they have not even seemed to be phased and they just keep growing thru it.

I've heard of people cutting off leaves that have issues at times but idk if this is a good way to respond to that. it is only two leaves but they are fairly bad on the small one. all the picture below are from the same plant

Is there a fan really close to this plant? That looks like wind damage, which is generally caused by having a fan blowing too strong on a plant.

if you water when the lights are on and it gets on the plant it will do that.

I have seen something similar but can't find much on the red rust on veins or the spots on any thread. Not fungus since there is no dust.

GreenBoxGrown said:

Is there a fan really close to this plant? That looks like wind damage, which is generally caused by having a fan blowing too strong on a plant.

Click to expand...

The fans are not very close to the plant, probabaly at least 12 inches away and on low speed. not sure if that's it. I am noticing more and more of the same spots on that plant. the only thing I thibj it may be is something in my tap water. also I bought a new ph meter(a very nice one) it will be here tomorrow. Although I have been measuring out the ph. idk if my meter is working right.