Hello, everyone. I brewed an APA about a week ago, and have had the end of the blow-off tube submerged in sanitized water the whole time. This morning, I went in to add some dry hops, and noticed that the tube fell out of the water. I looked at everything yesterday, and all was well, so I know the brew was exposed for less than 24 hours. I've read other threads where this happened during vigorous fermentation, and everyone said not to worry. However, the bubbling stopped at least a few days ago, so I'm concerned there wasn't enough CO2 being produced to keep the O2 out. Thoughts? Thank you!!