Here are some good sites for you!
I use liquid rid-x once a month as does my MIL. We've had no issues and her house was built in the 70's.
I never pour grease in the sink and wipe out anything with grease before washing. Check detergents to make sure they are septic safe.
Try to keep hair from going down drains.
No food or garbage disposal for food particles.
If you can, install a grease trap for kitchen sink and dishwasher run off.
Charmin is the worst toilet paper (according to a plumber I know) so make sure your toilet paper breaks down easily.
No feminine products flushed.
That’s good to know.
To keep the bacteria growth good, buy a product meant for septic tanks. Never put bleach into it through your washing machine. Don't damage field pipes by driving over them. Don't drive over the lid of the tank. Have it pumped when needed...they will fill up.
If it hasn't been properly maintained, Roebic makes an Emergency Septic system that I used to restore a clients system who had been quoted $7k to get it working again. I used it 2x about two weeks apart. I've had the best luck with this brand for many of my client's septic systems.... https://www.google.com/search?q=Roebic+septic+treatment&client=opera&hs=rLp&source=univ&tbm=shop&tbo=u&sa=X&ved=0ahUKEwiYk_qqq6jiAhUXsp4KHQyRAYIQsxgIMA&biw=1473&bih=696
Hi Linda: I grew up with a septic tank and my mom used Rid-X, but mostly she used yeast:) Yeast helps keep bacteria alive and actively breaks down waste solids when added to your septic system. What she did was to flush ½ cup of instant dry baking yeast down the toilet, the first time. Then she added ¼ cup of instant yeast every 4 months. We never had a problem. Good luck