It could go from 45 to 30 and wouldn't be "really bad". Humidity is important over an average, not as a daily number. If your air cells are growing at the right rate, it doesn't matter what the number is. If it spikes or drops, it isn't going to hurt them. Its all about the moisture loss. There's not much difference between 45 and 48.Ok so the humidity has gone from 45 to 48 for 2 hours, is that really bad?