The lid is press on & sold separately. 

It is all the way to the top. I use these for changing out the water in my aquariums, so I have it marked for every gallon, This is how I know.

Yes, it does come with a lid. I use the bucket when I clean my aquarium, so I am not sure how air-tight it is.

yes with the lid you should be good

Hi StevenJT This is just an ordinary bucket. It has no additional features. Thanks,

I have 5 PETCO buckets, and all hold 5 gallons. Measured an empty one at 14” tall by a bottom diameter of 10.5”. Bucket tapers very slightly more toward the top. 

Hi Winston191, This was not designed to hold boiling water. Thanks,

The bottom of the bucket says it's a "2."  And also says it's HDPE.  As far as I know, both of these identifiers indicate that it actually is food-grade.  And if it's not food grade, I find it really interesting that it has a food-grade price.  If not food-grade, this bucket should be half the price.  And if not food grade, we would obviously not want to put water in it and then drink it, but Petco wants us to put that same water in it and then put fish in that water.

Thanks everybody! Warmed it up in the shower with the water on hot. Came off nicely!!

It doesn’t have any gallon markings.