Humidity question PLEASE

im about to start blooming some kushberry and the humidity is at like 60-70%
is that too much, could my buds get mold from humidity this high?

most importantly how can i lower my humidity?

Yes, they could very well get powdery mildew. Nightime levels will always be more than daytime, so if possible, I'd advise keeping your exhaust going 24/7. I had to deal with powdery mildew myself pretty recently, and integrated a sulfur burner to deal with it. Prevention is far the better option though.