I went back and bought one. The car smelled like whiskey all the way home.
I'm not going to use a liner. I've got it full now. I'll dump it in a few days and repeat a few times. My temps won't be consistent enough for a few more wks.
I keep my grow out plants in clay pots in 2OL tanks. I'm just going to move the clay pots into the barrel starting with plants that tolerate cooler water 1st. As the weather gets warmer they can be swapped out with warmer water plants and finally fish.
The other nice thing about the pots is I can adjust water depth as needed. Some of the younger crypts will be closer to the surface until they get larger.