Leaf spots

[Spinach101]

I cant find anything similar on the Diagnose your plant, so forgive me if a thread exists for this - i just couldn't find it
I bought this UK Cheese clone, went away for a week, and came back to find this white spot on my leaves
The closest thing i can find on the diagnose your plant is spider mites, but it also doesn't really look like the picture on this site.
Now it seems to be moving onto the plant next to this one. - so i think its a bug
I am growing in organic soil,
The other 3 plants seem fine - except now one has a few leaves the same as this
I have used store bought organic pesticide(twice over 2 weeks) - pyrethrum, garlic,chillies - but it doesn't seem to help.

temps are 22-25 degrees
humidity is at 50-70%
ph is 6.5-6.9

Thanks for taking the time to have a look
Anyone know what i am dealing with here?

[Gjourney101]

Grab a good magnifier. Examine all parts of the plant including undersides of peaves. Infestation is culprit numero uno

[SoOrbudgal]

Thrips looks like

[Spinach101]

Thank you peoples, i will check with magnifier and treat for thrips .... your comments are much appreciated