Septic line clogged

I have one commode in my house where the lines are slow to drain. I have a company coming out to pump out my septic tank, but I think I may have another problem. The commode that is slow is "up line" from where it goes in the ground. I have a commode almost directly above where it goes in the ground and is draining alright now. It does make a "gurgling noise" when flush though. I think even after I have the septic tank pumped, I will need something I can pour into the one commode lines that will help clean it out. Any suggestions that will work? I started to get "Rid-X", but have seen on some forums that it is a waste of money. Thanks for any suggestions. The one line that will not drain right is about 25 to 30 ft. from where it goes into the ground. Thanks again..

From your description, we don't know if the problem is in the toilet or in the line.

When everything is working properly, you should be able to dump a 5-gallon bucket of water into the bowl and it should go right down.