How do you read results?

Hey everyone!

When performing a water test do you take the test tube and put it up against a white background to read or do you look down the tube? I'm having difficulties reading nitrates. If I put the test tube against a white background the results look close to zero, maybe just a hair darker then yellow. But if I look down the tube it clearly looks like 5 ppm. So which way to read it is correct?

 

Hey everyone!

When performing a water test do you take the test tube and put it up against a white background to read or do you look down the tube? I'm having difficulties reading nitrates. If I put the test tube against a white background the results look close to zero, maybe just a hair darker then yellow. But if I look down the tube it clearly looks like 5 ppm. So which way to read it is correct?

It can vary slightly due to light angles. Either way nitrates are very low. So that's good.

Are ammonia and nitrite 0?

 

I personally follow the instructions in the kit and put the tube up against a white background in a well lit room at eye level. 0-5ppm does not seem to be much of a difference as it is not a high number, but a water change can’t hurt!
Hopefully more experienced members can give their input as well!

 

Put it just a few inches away from the white background on the card and read it in the sunlight. Don’t put it against the white because it’ll look darker. But a word of advice, it’s really hard to distinguish between boxes. If it’s red it’s bad if it’s yellow or orange you are fine! For nitrates anyway.

 

I always hold it against the white part of the key. As Unknown pointed out, being in adequate light helps.

 

It can vary slightly due to light angles. Either way nitrates are very low. So that's good.

Are ammonia and nitrite 0?

Ammonia is steady around .5ppm nitrites are 0

 

I always hold it against the white part of the key. As Unknown pointed out, being in adequate light helps.

I agree with this 100%. Depending on The time of day it can definitely affect it for sure.

 

I read it with sunlight by a window against the white background. Or right under a bright light at night time.