Brown spots, calcium def or fungi

What was the white powder/spots/? on the leaves?

I see no horrible things here, iam just guessing for some spilled liquids here. just pick the leaves if its going worse......If leaves are so close to the medium they look like that if you spill liquids upon them

Also, yes, that looks like a mold (PWM). Don't spray your leaves and if that mildew spreads, cut off affected leaves or destroy and start again. Sorry, wish I had better news. Humidity shouldnt be over 60% at this point.

Check your pH and EC of runoff. Looks like a pH problem or over/under feeding. Calmag is also a possibility, but it shouldnt be consuming too much calmag at this stage anyway, so unless you're 100% devoid of any calmag, I'd look at other issues. Your feed should be very low right now, no more than 50% of manufacturer's recommendations, but 25% is probably better. If you are feeding, it should have started in the last 5 days or so at the earliest.

Be better to tie the question to the diary, open it there so people can easily see what they may need to to help you. The leaf has CA spots dont know about the white stuff perlite maybe If not getting any may wish to add a small amount of cal-mag, @1ml/gal to start but see no nuets at all on diary so all I can say