You are right, but to be fair most things that are petroleum based are made with it because of economic reasons. Many things don’t need to be it’s just cheaper that they are. That’s because of a combination of factors. If tomorrow every oil field in the world disappeared we would see alternatives for almost everything almost instantly because there would be huge financial incentive for it and many of those things already exist, they just have to compete with a very established and subsidized raw material
Very cool! I think I might do something similar but might first try with regular pots. Not sure I want to jump into hydroponics right now.