should i switch to blow off tube?

hey all,
This is my first batch so that should tell you how new to this game i am. my beer has been fermenting for 6 days now in a plastic 5gal bucket. the first 4 1/2 days the lid wasnt properly sealed so there were no bubbles happening in the air lock. after resealing bubbles started come out of the air lock. After i got home from work foam had been pushed up through the air lock. i read a few threads saying to switch to a blow off tube, but im not sure if its necessary because im already almost a week into it. any thoughts?

First - I'm not sure why people don't automatically set up a blow off tube... granted if you have 6-8 inches of headspace, maybe not needed. If you use buckets or if you have only a bit of headroom, put a blow off tube right from the start.... saves problems later.

Blow off tubes always from the start... no reason not to

I got an eight gallon bucket. No more worry about overflow! My airlock is empty every time I check it at times when I've got a strong fermentation going, but the only mess is starsan from the airlock on the bucket lid.

I'm going to pick up another eight gallon bucket or two.

As for dilger's question, I wouldn't worry about a blow off tube at this point.
You've got the better part of a week on the fermentation now.

If you used sanitizer in the airlock, it tends to get bubbly just with the air escaping. That doesn't necessarily mean that any yeast or mess is escaping. If you haven't seen the difference before, it can be easily confused.

Either way though, a blowoff tube is a cheap and easy way to ensure against a huge mess. I personally use them in every fermentation and just leave them on the whole time. The only time I switch to a airlock is if I have to open the fermenter to dryhop, take a final gravity reading etc

you could just have too much water/sanitizer/whatever you use in your airlock which is forcing it to bubble over. So long as there isn't wort and yeast bubbling through I'd say leave it but you should always have one handy if not using it from the start.

Unless you are using a vessel with a very large headspace it is best to start of EVERY fermentation with a blowoff tube installed.

If you don't, at some point you will be cleaning up a mess!