Hi Tom, here's an update. Sewer line from house to tank augered out, Ran hose in line for 15 min while cleanining it out. Filled tub over half full.. Upon draining everything was fine. Tub used again two hours later drains fine, I Use two hours after that, Downstairs toilet does not back up, but big bubbles come int o that toilet.. Coud it be that the vent is not good (big) enough for the tub? This is driving me crazy! Thanks for any and all help.

Hi BS,
When your fixtures begain to talk back to you they do it in two ways. They "gurgle" atcha or they "bubble" atcha. The "gurgle" is caused by vacuum caused by a blocked vent. The "bubble" is caused by back pressure due to a partial blockage or a septic tank that, (if filled up because the drainfield is no long able to handle the discharge from a fixture that dispenses so much volume in short a period that it loads the tank up), needs to be pumped. Since you say you have a bubble, indicating air being forced back up the sewer line by the sudden backup of discharged liquid.
I would check the tank itself to see if it needs to be pumped. If the tank's full and should be pumped I would also want the drainfield checked to see if I had a problem there. Somewhere out there you still have a partial clog. Good luck, Tom

The tank was pumped on Thursday it is empty, that's why we can figue it out. Line is open from house to tank.Line going to leach field is open also. We tested the sewer line by putting a hose in it for 15 minutes and running it full bore, there wsas no back up or anything. Tub was drained twice earlier in the day with no problems. Then when I used it it bubbled back into toilet when tub was almost empty.

Backups indicate only one thing. That the discharge is hitting a obstruction.
" Tub was drained twice earlier in the day with no problems. Then when i used it it bubbled back into toilet when tub was almost empty."
Have you pulled the toilet and snaked out its drain line? The fact that you still have a problem tells you that you've missed something. Please keep me in the loop on this one. Tom

Toilet line was power auger out on Sunday. Went out twenty feet..

Toilet line was power auger out on sunday. Went out twenty feet..
Something was missed. Otherwise you wouldn't have the same problem.
When that happens to me I take a deep breath, mutter a few choice words and treat the job as if I was starting the job from scratch. Now I'm not happy about this because it means going back and redoing everything I did before. In doing this you can't assume anything. EVERYTHING must be done again and done right.
But nine times out of ten I'll run into something I missed. Perhaps I didn't run the snake out far enough. Maybe I missed a vent I should have gone down,
Somewhere out there is the reason you have a backup, you know that it took most of a tub full of water before it backed up. This would indicate that the clog was out a ways. Why it comes and goes I don't know but if you find out let me in on it. If the tank hadn't been emptied I would say it was loading up with water and backing up. Then the drainfield took the water away until next time. But you say that's not the case. Go back and see if there isn't something you've missed. Good luck and keep me informed. Tom