I just removed the aerator from our dual chamber septic tank. It was in less than 6 mos. I noticed flow was slowing after a few mos. so I cleaned the filter and took a sample at the turning structure. It was clear. The last check revealed some solids made it past the tank filter and down to the filter I had installed just before the field. I wish the filter in the tank was more successful, but I don't feel like cleaning filters every couple of mos. For now the tank will go back anaerobic and I'll continue to aerate the leach line clean outs. I may add a 300 gal. tank just beyond the septic tank for aeration like I mentioned before.