After 23 years of home brewing I can assure you with a 100% degree of certainty that you don't even need to put the freaking lid on your bucket at all if you don't want to. Back in 1994 I spent $6000 and bought a 20 gallon gravity feed pilot brewery. I thought I was the shiznit. My fermenter is 20 gallons and made of 1/4" stainless. This thing is what every homebrewer would die for and, I have to tell you, half the damn time I don't even put the lid on it. I often just throw a towel over it. It has a connector for the blow off tube. Most of the time I just set the lid on and don't even bolt it down or hook up the blow off. When I lager, I use 4 kegs in a freezer. I don't use a blow off because when the kegs are not under high pressure they leak around the lid. Nothing blows off. Been doing it this way for over 2 decades with many, many, awards (best of show awards included) and, I have never had a bad batch. As Homebrewers I believe we try to overthink this stuff too much. Get a bigger carboy.? Fine. Use a blow off tube.? Fine. What you should do is just one time try leaving the lid off the bucket (Throw a towel over it.) and you will get the confidence in the process that I am talking about. Remember what Charlie says? "Relax. Don't Worry. Have A Homebrew." He knows (and so do I) what he is talking about. Stop trying to be a commercial brewer and be a homebrewer. Our beer is far better than theirs is anyway.