Failed Lateral Flow Device
If there is no control line visible on either of the two LFDs, then the test is invalid and must be run again using a new test kit. Re-test even if there are lines opposite the "T" (Test Line)

Negative Result
When the test result shows Control Lines and Test Lines on both the LOW and HIGH LFDs, then the test is negative. This means that there is no contamination or, if there is contamination, it is at such a low level that it requires no immediate action. Note the different strengths of the "C" and "T" lines. This is normal.

Low Positive
When the test result shows Control Lines on both LFDs, plus a Test Line on the HIGH LFD, but no line on the LOW LFD, then the test is positive at the lower of two settings. This means that there is contamination present and it is at level that requires the application of biocide.

High Positive
When the test result shows Control Lines on both LFDs, but no Test Line on the HIGH or LOW LFDs, then the test is positive at the higher of the two settings. This means that there is contamination present and it is at a level that requires the application of biocide and tank cleaning.