I would flush with plain....ph correct water.....no nutes. As far as WHEN to start your nutes back up I'm afraid I really don't know....hopefully a soil growhead will stop by and tell us.

If you have white spots on your plants with your high humidity chance are (without seeing pics) it is powdery mildew. You'll need a good fungicide for it.....Stinky says she's had good success with neem oil but I'm afraid I'm not sure how to use it.

Your very high humidity will contribute to your defs and cause mold/fungus issues. You REALLY need to get your humidity down somehow.

I wouldn't quit now......unless you solve this issue what are you going to do if the next grow has the same problems?

Good luck blink.