API No. 3 Test Kit Nitrate Liquid Test Kit

Liquid Test Kit for API Nitrate Measurement for Sale
Amazon List Price: ￥9,359

This test kit is very easy to use.
Fill the included test tube with water up to 5ml. The test tube has a 5ml marking, so just fill it to that line.
Next, add 10 drops of Reagent 1, followed by 10 drops of Reagent 2. Close the cap and shake well for about 5 seconds.
Then, wait 5 minutes, and compare the color of the water to the colors on the test card.
It's that simple.

I purchased this 2 years ago, but since my aquarium water quality was good, I only used this test kit a few times.
It allows for a total of 90 tests, and there are definitely more than 80 tests remaining.
I have also weighed the bottles and their contents, which you can see in the photos.

If you check your water quality once a month, it will take over 6 years to use it all up. Each measurement only uses 10 drops of each reagent.
Alternatively, if you only use 2.5ml of water, you can also measure with 5 drops of each reagent, and it will produce accurate results. This method allows you to double the number of uses.

Please understand that this is a used item if you are sensitive about such things.
Thank you.