I like to keep my humidity around 65-70% Otherwise I worry it's too humid. I've had mine spike like that too and chicks were fine. I'm still so very new so really don't have a lot of results one way or the other behind me. I've read so many different things about what everything should be, some of them scare you to death making you think you've done everything wrong. Research some more and go with what you think is best, trial and error are your learning tools here along with experience from others. I've been grateful to those who offered me advice and condolences and helped my guilt to subside when things went wrong. They also gave me the courage to try again after learning from my mistakes.