Digicop
Community Member
- Joined
- Feb 4, 2020
- Messages
- 89
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- Location
- Rayne, LA
- What state or country do you live in
- Louisiana
While this conclusion is probably common knowledge for all of you journeymen out there, it may help another newbie like me, which is why I am wasting your time posting the results.
I am very new to the saltwater aquarium world and did an experiment this morning to figure out if when you measure Nitrates using a color-based test, does measurement time make a dramatic difference. Turns out, it does. Immediately after testing, the test shows almost no Nitrate and at 13 minutes shows around 10 ppm. However, between collection and 5 minutes, the spread is 2-5 ppm. Plus, I can't distinguish the difference in measurements by eye alone.
For this test, I used the API Nitrate Test Kit ($13.00) with an expiration date of 2/2024. I collected a sample and took photographs using an Iphone X at 30sec, 1, 3, 5 and 13-minute intervals. The photographs were taken in a diffusion box beneath 5600K lights. The photographs were imported into Adobe Photoshop where I color corrected using a curves adjustment layer and an 18% grey card. I then measured the chart and test with the eyedropper tool set on HSB (HUE, SATURATION, BRIGHTNESS). I then measured the hue for the guide chart and the different tests.
The guide chart measurements were:
0 ppm = 55 HUE
5 ppm = 44 HUE
10 ppm = 41 HUE
20 ppm = 34 HUE
I then made the following measurements and estimated ppm using the hue from the guide chart:
30 sec = 53 | Estimated ppm 2
1 min = 49 | Estimated ppm 3
3 min = 45 | Estimated ppm 4
5 min = 44 | Estimated ppm 5
13 min = 42| Estimated ppm 9
I found adjusting the image to perfect exposure using the grey card made very little difference in the test results.
30 Seconds:
1 minute:
3 minutes:
5 minutes:
13 minutes 30 seconds:
__________________________________________________________________________
Ricky Gray
Lafayette, LA
48 gallon octagon saltwater running Aqueon cannister canister filter and Fluval Sea LED lights. Tank was started 12/26/2019.
I am very new to the saltwater aquarium world and did an experiment this morning to figure out if when you measure Nitrates using a color-based test, does measurement time make a dramatic difference. Turns out, it does. Immediately after testing, the test shows almost no Nitrate and at 13 minutes shows around 10 ppm. However, between collection and 5 minutes, the spread is 2-5 ppm. Plus, I can't distinguish the difference in measurements by eye alone.
For this test, I used the API Nitrate Test Kit ($13.00) with an expiration date of 2/2024. I collected a sample and took photographs using an Iphone X at 30sec, 1, 3, 5 and 13-minute intervals. The photographs were taken in a diffusion box beneath 5600K lights. The photographs were imported into Adobe Photoshop where I color corrected using a curves adjustment layer and an 18% grey card. I then measured the chart and test with the eyedropper tool set on HSB (HUE, SATURATION, BRIGHTNESS). I then measured the hue for the guide chart and the different tests.
The guide chart measurements were:
0 ppm = 55 HUE
5 ppm = 44 HUE
10 ppm = 41 HUE
20 ppm = 34 HUE
I then made the following measurements and estimated ppm using the hue from the guide chart:
30 sec = 53 | Estimated ppm 2
1 min = 49 | Estimated ppm 3
3 min = 45 | Estimated ppm 4
5 min = 44 | Estimated ppm 5
13 min = 42| Estimated ppm 9
I found adjusting the image to perfect exposure using the grey card made very little difference in the test results.
30 Seconds:
1 minute:
3 minutes:
5 minutes:
13 minutes 30 seconds:
__________________________________________________________________________
Ricky Gray
Lafayette, LA
48 gallon octagon saltwater running Aqueon cannister canister filter and Fluval Sea LED lights. Tank was started 12/26/2019.
