Manchas en hojas

Estaba en la parte superior , si recibia luz y la humedad no supera los 60%

It looks like powdery mildew but the rest of the leaves on your plant look fine, how many fans do you run ? good air circulation can prevent powdery, also what is your RH in the grow area ? To prevent or treat Powdery Mildew you can mix a tbsp of Baking Soda with a liter of water, wash the infected leaves and afterwards spray the plant with the Baking Soda water mix, that prevents and kills any Mildew that is there or might form again.

If this is down low and youre in a himid environment, this could be powdery white mildew, but doesnt look bang on. If its the one leaf, toss it and monitor all feeds. If its migrating, flush and water plain for a bit. Peace, good luck

where at on the plant was this leaf located?