What could this mean?

A few weeks ago my plants had this problem but way more severe, i flushed with florakleen and the new growths started being completely green and healthy, a couple weeks later and it's slowly creeping back, could this be nutrient burn or is it deficient in something?

Check your Ph

Looks like a Calcium Def. or spider mite damage. look under your leafs for bugs.
Is your Ph Low?

Looks like thrip damage to me

I usually keep 20 to 30 lady bugs in my garden just so that they can eat any unwanted pests. You can order a large pack of live lady bugs off of amazon for around $10 with shipping.

I usually keep my ph around 5.3-5.8. I use the ph indicator drops and it's hard to find an exact match, it's usually yellowish brown. I checked some damaged leaves with a 80x microscop on both sides and there are no bugs. I'm thinking it's a calcium def. But not sure if i want to go ahead and add some calcium if i'm not positive.

Looks like the start of a Ph issue. Are those spots turning brown or rusty colored? If so you need to check you Ph it may be low. It could also be a calmg issue. 5.8 is too low IMO I was watering mine with Ph that low and I started to have rusty colored dead spots on some leaves. I bumped the Ph up to 6.0-6.2 and all is well now. I would also keep an eye out for bugs that may be eating your plants.

^did exactly what you did and i think i got the problem under control dude thanks intenseneal!