52 days since seed in soil. Something to worry about? How much PPFD?

Sorry, I forgot: it's a pest. Here in Europe, we call it a "leaf miner."

Plant is far too lime check ph, no point fixing a deficiency during potential ph skew. Veins of leaf and stem. Red/purple, oxygenation of the medium is a problem. Tips indicate ec of soil around 1.6ms/cm almost at limit. Tips drooping tells me water/pressure issue, Likely iron us messed up from a combination of high ph and iron becoming toxic from the oversaturated medium. If ph is above 7 there will be no hydrogen either. Need to get your ph to 6.5 open up the hydrogen, get water moving faster via transpiration or iron won't work properly in a soiled medium. Oxygen, oxygen, oxygen.

Ca,Mg,P def if u see yellowing beneath then also N ppdf 1500

The Damage on the leaves reminds me of a pest but its not typical of the kind I normally see. Its almost like a hybrid of Leaf Miners and Mites. Somewhat following a pattern or trail on the leaf but in dots like mites but the dots are to big.. Check the underside of the leaves and see if their is anything there, if not it might not be 100% a pest. The pattern is mimicking on other leaves and between the veins on the same canopy height. Don't spray the leaves with anything as well to rule out that as a option.. Over all plants are looking good. your watering habits are perfect. It is boarding on the edge of over feeding from the mini tips that are looking a bit burnt. I would knock it back 100-200 on the PPM scale or 0.2-0.4 on the EC scale and maybe get a bit more runoff next feed. If you have a root booster for microbes or fungi I would use it. Voodoo juice is one suc product or great white.

It looks like thrips scarring, but I don’t think it is. I’d definitely run this one in Ai like bud said.

Post the pictures to ChatGPT along with your Diary, then you will get a way better answer and solution than we can give IMO. You can ask ChatGPT exactly like you done here and post the same pictures. Then it will give you a long and detailed answer. Best of luck! ChatGPT.com

35-40 dli, but you probably already got that dialed in if it didn't get all lanky or stunted. It's an autoflower, so you aren't changeing hours of operations, so just keep doing what you were doing. change of hours requires an inversely proportion change to PPFD to maintain same DLI. DLI is what matters. PPFD without hours of operation could mean one thing or another. Also, ppfd is the average across the entire canopy and not just the hotspot directly under the light. temp, rh and atmospheric co2 dictates how much photosynthesis a plant can do per day. It's not a choice we make. Looks like you may have some pests chewing on your plants. otherwise, looks fine

looks like some kind of leaf parasite , would remove just the leafs-parts with this in it.