Has anyone used the Red Sea Plant Lab that measures Fe and CO2? I have a Red Sea CO2 DIY and I measured the CO2 tonight and its saying I have like 6ppm, which is nothing. I know I need like 25 to 35ppm. I know I have to make a new batch for the container, but does 6 ppm sound reasonable. It is not an extremely heavy planted tank, but it is close of being there. Just wondering how accurate this test kit really is. Thanks.