Looks to me like more than one thing going on-

The "speckle" damage sure looks like feeding- I associate that pattern with mites more than thrips, but Stinky's our resident thrip expert ( ).

It also looks like you've got some edge necrosis that I'd be thinking was more likely micro related- but it looks like your macros are OK, so probabley pH.

Check pH of source water, mixed nute, run-off- In that much moss, I'd wanna keep feed pH pretty nuetral ( 6.3+) and make sure that media/run-off is staying 5.8 plus. Media/run-off is the measurement that matters here.

I'd also look at the underside of damaged leaves w/ a magnifiying glass- mites/thrips are not something that you're going to see w/ bare eyes. Even w/ glass, I'd be surprised if you see an adult thrip. ( Imagine if Salvadore Dali was designing a lobster). Mites look like tiny spiders, because they're tiny spiders.