Nah, at the end of the day a tub is just a kind of container. As long as you have a way to keep the ambient temperatures up decently, you can grab the biggest one you can find and put anything you want in there. Use coco-fiber, put in live lucky bamboo, put in fake foliage, put in branches, put in moss - I've had all of that in a tub. I like pvc better because there's better options for raising ambient temperatures, but you can make a pretty complex setup in a $20 plastic tub.