It’s neither a lack nor an excess... I think this is for you dropping
the food on the leaves when you watered, and it burned a little in contact with the lamp or thrips, but I wouldn't say, it just reminds me a little,but I'm not sure, wait for someone else to contact you.
Also pour the water at least a couple of hours before watering to let it stand for a while because tap water is full of minerals and who knows what else they put in it to "purify" it.
For the most part, this looks great to me, I wouldn't worry if I were you, I don't believe this is anything serious