You have to have a timer to grow weed. Any extra light over the 12 hour mark is going to confuse the plant and make it herm. Also if your temps are in the high 80's, you clearly don't have enough ventilation. And if your temps are touching 90, chances are your water is too hot too which will rot the roots and cause herms as well.

__________________
The above post is fictional and should in no way be taken as truth.

If I were to grow cannabis, I would only do so to supply myself and my close friends. Doing this would take myself and my friends out of harms way by knowing the source of our cannabis, as well as take hundreds of thousands of dollars off the black market annually. It would also lower the demand of black market cannabis, and would ultimately help keep cannabis out of the hands of minors.