> I noticed that the Sera iron kit starts at 0.25ppm. Is there a way to > measure iron at 0.1ppm with this kit? > I believe if you start with 2.5 times as much water there will be 2.5 times as much iron to react with, therefore 2.5 times as much sensitivity. The indicator color may be a bit washed out, but the color should be correct. -- Harvey Schneider <harvsch at earthlink_net>