Help reading API freshwater Kh/Gh test kit

[Ponch]

I bought this test kit yesterday and am confused how to read the results.

With the API master kit I place the water & solution filled test tubes up against the color chart and determine closest color to get the results for each specific test.

Reading the instructions for the Kh/Gh tests it says something like "if you have difficulty reading the results place the test tube over a white surface, remove the cap and look down into the top of the tube".

The problem is, to get blue changing to yellow (Kh test) looking down the tube takes ~3 drops but holding it flat to read against a white surface takes ~10 drops. Same thing happens for the GH test. So how exactly should I be reading this test - top down or flat against? Left a message for mars pet care about this and waiting for call back next week. Any help is appreciated. Thx.

 

[kelbaker79]

I always hold the tube up to a white wall and compare to the chart. Not right up "against" the wall, but up close to it....

 

[Ponch]

I always hold the tube up to a white wall and compare to the chart. Not right up "against" the wall, but up close to it....

Are you reading the kh/gh tests the way you described or just the ammonia, nitrate, nitrite and ph testing? or are you reading all of the API tests this way?

What You describe Is essentially what I do too for ammonia, nitrate, nitrite and ph testing... But the directions on the Kh/Gh kit lead me to believe those tests may be read differently ( especially considering API does not provide a color chart for these two tests ). And I'm seeing there are significant differences in results depending which results reading method is used.

 

[Aspencer]

I have trouble with gh...the first drop I put in is just barely orange and the second drop is very light green so i assume it to be two drops...I have put more but the green does not get greener.