Leaf discoloration - light and dark splotches

So going based on your diary this could be a few things. 1) Is it at all possible that nutrient water was spilled on that plant? It looks like it could possibly just be residue from nutrient salts. 2) I don't see any calmag supplements listed in your diary. Are you using any? In hydro calmag is a necessity and a calcium deficiency in it can start out with some light spots like that. On top of that, it is a good idea to feed a light dose of nutes in hydro once the first true leaves develop or growth will slow down. 3) Your PH is in range for hydro, but it is at the very bottom of the range. Calcium is absorbed around 5.8-6.0 PH. I wouldn't go above 6.0 PH. I grow in coco which is a hydro medium and started noticing some issues when my PH drifted to 6.1 or above. If you need any more help/advice feel free to message me! Good luck!

Hello.. Hope you are well.. Just had a look thru ur dairy.. Everything seems ok.. Try raisng ur lamp a few inch (upto60-70cm?)..ur humidity is a bit low for young plants.. Raise her upto 50% if possible.. Also id raise ph to around 5.8-6.2 if possible.. Are u spraying her wen lights are on.. It cud b burn if so.. Hope all goes well with her.. Stay safe n gud luck.. 👍🍀