How to build an ecosystem (2017) (sciencing.com)

This is cool but it needs more pictures of what the end result could look like.

If you follow the instructions for an aquatic ecosystem, please don't follow their advice to use goldfish. Goldfish need a big tank because they grow up to a foot long during their 10-15-year lifespan. It would be better to pick a so-called "nano" fish like a rasbora or tetra.