system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How Septic Tanks work.

Explain like I’m 5 how septic tanks (US if it matters?) work please. I hear so many horror stories of plumbing backing up that I am terrified it’s going to happen to me. 

Do I need to try to limit water usage (or pouring extra water) down the drains instead of outside?
gpt
Septic tank attaches to the outgoing pipes of your home. They are generally a large concrete box that houses the waste from your toilets. There is a pipe that leads out to a tube with holes in it surrounded by limestone allowing the water to escape. This is called a leach field. While inside the tank bacteria and yeasts break down the waste. The broken-down waste is constantly taken out by the water that runs out into the leach field. Occasionally septic tanks require being pumped out, but generally, as long as the bacteria and yeasts that break down the waste remain healthy this is not very often. You can buy yeast that you flush down the toilet occasionally, flushing large (abnormally large) amounts of chemicals down the drain can hurt the life in your skeptic, but regular use is fine. Don't flush anything that will not break down naturally like wet wipes, and paper towels are not a good idea. Now you should have warning signs before you need to have it pumped like the smell of waste in your yard or water leaching above the surface of the ground where the caps of the tank are.