It would probably help if you provided what numbers you used and steps. Also what makes you feel the reagents are any better than Neptunes?
As far as calibrating using manual test results my recommendation may be a bit more extreme but this is how I have done it in the past.
- Collect water sample as close as you can to the Trident sample line
- You want enough water to run both manual tests and Trident calibration (2 cups or so - depends on how much you need for manual tests)
- To get the manual calibration numbers run at a minimum 3 test, 5 preferred
- Average those numbers (I use the 95th percentile but I actually calculate avg, median, and 95th)
- Once you have your calibration numbers start the Trident calibration task
- Enter your results
- Use the left over water from your manual tests for the sample line
- Follow the Trident task until done
The key for me was to collect enough water to run both manual tests and Trident calibration. You want to use the same water to finish the calibration that you used for the manual test(s). Running 3 tests and using the average or 95th percentile will make for better results. It also helps you confirm both the human factor in the manual test as well as the test kit. If the numbers are all over you will notice it.
Is this what you ran into? I don't know. Just sharing how I go about it. I actually use the supplied calibration solution because it has worked for me. However I have also recently used the manual method I note above. Your mileage may vary.