Good evening everyone. Here is my situation.
-We are on septic tank that was pumped about 9 months ago
-When washer drains, the sink 'gurgles', both toilets(same level) bubble and both bathtubs back up... only happens when the washing machine drains
-I have snaked all roof vents, toilets, tubs

The sink has 'gurgled' since me moved in about 4 years ago, but the bubbling toilet, etc. has only been in the last week. Any suggestions. Thank you.

A bubble indicates back pressure from something. Let me explain what's happening. You cycle the washer, The discharge picks up speed and bangs into the partial clog in the line and starts to rebound back pushing a bubble of air ahead of it. This is what you see in the toilet. Then the discharge drains away. This can only get worse. The drainage line needs to be snaked out . It sounds like something was missed. Or it could be your system isn't large to handle the extra volume put out by the washers more powerful pump. Good luck, Tom

Thanks for the quick response Tom. The house was built in 2000 so hopefully wasn't too cheap to install a decent septic system, but who knows. I've snaked the lines with a small manual auger. Should I call in a pro to investigate? Also, I've read that the cleanout should be about 18" away from house. Found the tank but no luck with the cleanout. It should be between the house and tank correct? Thanks again, Tony