So I brewed a batch of IPA last night, and I've got serious krausen going on in my fermenter today. I just checked on it, and some of the foam has worked its way into the airlock (the sanitizer is now a brownish color.) It's a 6-gallon carboy with a 5-gallon batch so I didn't think I'd need a blowoff tube. I'm assuming it's harmless because the airlock was full of sanitizer, but I just want to double check.