How To Properly Read Master Test Kit?

[pkppv]

So i got master test kit after using the little paper strips for a while. I read all the instructions, and did some testing, but i cant seem to figure out how exactly to read it. Do i hold the tube up to a bright light? Do i read it in normal lighting? Because depending on which of these i do i get vastly different results.

 

[MBOU]

Natural daylight or you can see between the yellow of 0 ammonia and the green tinge of .25 ammonia.

Natural daylight and hold the tube up against the white part next to the right colour chart...

 

[pkppv]

Ok, but more specifically...in bright light nitrate appears a light orange of about 20ppm but in dimmer light it appears to be nearly 80.. which is right?

 

[eaglesaquarium]

Natural light, so I would lean towards the low side.

 

[RobberyinCSharp]

I agree with eaglesaquarium. The way I go about it is in natural light. Hold the test tube on the comparison chart on a white section. The side which has the most light (no shadow casting) should be facing the comparison chart. Get your read off that and you should be all set!

PS: the nitrate tester is a pain in the neck and is highly inaccurate if you don't follow instructions perfectly. Really shake the second tester well for 30 seconds, and leave the test tube to sit for about 10 minutes before you look at it. It's a headache!