API freshwater master kit

[phin9009]

So I have what may be a stupid question, but how exactly are you supposed to read the results using this test kit? I know with the white behind it, but do you allow space and light behind the tube or do you hold the tube against the card?

 

[Sow3r]

Against the card. White part

 

[phin9009]

Ok thanks. Wasn't sure, and there can be quite a difference in the color for some results