Yellow spots

I used to have a similar situation when I used a humidifier, water formed on the leaves and left a salt deposit on them. A little fan gently mixing the air should help. Good luck :)

Could be because your soil Ec level is to high causing a slight nute burn.

If you are wetting the leaves when watering, this can cause what you are seeing. The dissolved mineral salts left behind once the water evaporates will burn the leaves, especially at the ends/margins, as this is where the water drips off the leaves. Cheers, Organoman.

When it starts from the edges and/or the the tips of the leaves, at the beginning of a growth, it’s mostly due to a high EC level of the soil. There might be too much nutrients in the soil, or you’re not using enough water when you water your plant and getting no drain from the bottom, which makes the EC goes too high.