1-2 weeks!
Just curious, have you actually tested your reactor effluent with the photometer and you noticed a difference in the levels?
I'm not testing fanatically anymore.. but I noticed my reactor effluent was 0.0 for about 2 days then after that it started to climb. So now I'm wondering now if it wasn't precision error (ie. the "to within 0.04" thing) after all, although I still think 2 days is awfully fast for phosban to exhaust itself.
