70% isn't bad.
I know some people have 70-75% as a constant humidity. I personally like to keep my tubs around 60-65%. As long as there is no standing moisture on the bottom or sides of the tub, you're fine. I know the caresheet says 50%, but I honestly think that's low. If you look at the humidity in Africa, it is higher than that.


Also the Acurites aren't always exact. I've had several that all read something different. They were all at least ~10 degrees and ~10% off from each other