Yes, I know it's a crappy subject, but I need to replace my current toilet, and am looking for some advice. I am on a septic system, which has been failing due to my current toilets leaking all the time. The cost of reparing them doesn't make sense, so a new unit is in order. My question comes down to choosing between a 6L or 13L tank. While the 6L would be better at helping the septic system due to less water, I am concerned about flushing power. If I have to flush twice each time it defeats the purpose. I am looking at getting a Crane (Cadet or Radcliffe), since I will also need to replace my tub soon as well, and I want it to match. Thoughts?