We built our house and had 2 adults and 4 kids in the house, and never had the septic pumped in 15 years. It eventually filled up and I had to have it pumped. I didn't think much of it and felt pretty lucky to make it that long. The pumper said the tank was just full, but otherwise looked fine. Fast forward just under 2 years later with only 3 of us left in the household and it's full again. I suspected maybe the lines had gotten clogged with it filled up the first time, so I paid $1600 and had the lines jetted and all checked out fine. They said there were a few things in there, but nothing critical and all looked fine. Only the first line was black, the others were just brown and he said I'm not even utilizing half of my leech field. All was pumped, cleaned and put back together. That was exactly 3 months ago and my plumbing is backing up again.... During the 15 years we never put any kind of additives in, but after pumping the first time they recommended "Honeyzyme" so I used it. Not every month like they recommended, but about every 3-4 months thinking just a boost should be fine since it lasted 15 years without it. Since it backed up within 2 years, after the second pumping I definitely have been following the once a month thing. Why is it backing up again within 3 months of being pumped when we only have 3 in the household? We have had a few guests over once in a while, but nothing that should be causing this. Does my tank need a kick start, or do I need to quit putting additives in it? And is there anything I can do to recover it without pumping a 3rd time already?