We recommend you use a blow off tube for at least the first few days of your primary fermentation

Just like with any fermenter (plastic bucket, glass carboy, plastic carboy, etc) if you are making a big beer and you are relying solely on a small airlock "bubbler" right out of the gate even in the first couple days of fermenting, there is always a chance you can have an over pressure situation and a mess (and potential damage to your fermenter if the airlock bung becomes clogged and pressure builds up inside your Bucket)

Which is why we strongly recommend using a blow off tube initially versus using just a bubbler. We have an elbow attachment here on our store that mates with our brew bucket lids (Blow Off Barb) 

A ½” ID silicone tubing fits perfectly into the stopper hole on our Bucket lids! Not by accident, but by design!