The yellow tips can be a sign of over feeding.
The yellow dots could be fungal damage.
I would be removing the humidifier, it is not really needed and especially not during flowering. I would also suggest cutting back on the strength of the fertilizers you are giving, or giving fertilizers less often. While the plant is not suffering any great damage at this stage, trying these suggestions should see your plants returning to normal health.
Hope this helps, Organoman.