Why don’t the water values match my JBL drop count test?
Each test has a fixed scale, which enables the allocation of the water values. For example the steps in a drop test are different to those of the ProScan. Therefore ProScan also has a scale to enter the values and to avoid jumps at repeated measurements. Bigger differences between the values mostly indicate an incorrect reading caused by shades/reflections. Best is to carry out the test near a window with bright light. Direct light from above casts shadows or reflections which can affect the colour rendering. Please remember ALWAYS to shake the water off the analysis strip sideways. “Puddles” can cause the colour fields to react with each other and to produce reflections.
Incorrect values can occur through expired drop tests too (i.e. tests which have been open for more than 9 months) or incorrect use (with air-filled drops and deviating water quantities). In this case please check your measurements once more.
One example:
The aquarium has the following water values: 18 mg/l NO3, 0.5 mg/l NO2, 5° dGH, 7 mg/l CO2, 1.5° dKH, 6.8 pH.
The measurements with the different systems give the following values:
The ProScan shows following values: 18 mg/l NO3, 0.5 mg/l NO2, > 4° dGH, < 15 mg/l CO2 (by way of calculation), 1.5° dKH, 6.8 pH.
The drop test shows the following values: 20 mg/l NO3, 0.6 mg/l NO2, 5° dGH, 10 mg/l CO2 (by way of calculation), 2°dKH, 6.8 pH
Both results are very precise and differ only slightly from each other. This has no negative effect on further statements and actions. Inaccuracies in the application have a greater effect on the results than jumps resulting from the scale. Finer scaling steps could result in an inability to allocate the results exactly to the same measuring points when there is some divergence of light and distance in the surroundings. This would cause the values to jump again in a repeated test.