Hey guys not sure where to post this but need ideas for making a environmental project for my E Tech class was thinking about a aquaponics but I'm thinking that some of my other class mates might be doing it to so looking for some other ideas

Not looking for anything really expensive as I am still in high school but I would love to hear any ideas you guys have thx

potato battery

or just get a mirror and cover it and when people come to see what you mean by "under this sheet is the reason the world is becoming a toxic dump" and then remove the cover.

cheap, easy, and to the point.