Critters in my grow!

I can't actually see them on any of the leaves & I'm not seeing any flying critters so I'm not sure what is leaving these marks. Can anyone tell me what these marks look like they have been caused by?
Thanks in advance

Many different types of mites, some so small to see easily, check with magnification, reminds me of spider mites

I'll have another look at lights on. This has been going on for just over a week. I would have thought if it were the Borg I'd know by now. Fortunately they are due to be harvested next week so this has not caused a huge issue. They said I would like to get some natural predators in on the next run.