Unsure How To Read Salifert Test Kits

[rms]

Hi all,
 
This may sound like I'm being really stupid or anal, but how close should you place the colour chart to the vile when reading these test kits? Also lighting seems to effect the result. Further to this, should you place the colour chart under the vile or behind it? I'm getting very different results trying each and it's also quite hard to measure when you only have 1ml of water to gauge. The instructions really aren't clear to me, particularly when it says both behind the vile and under the vile can be read. At the risk of a pun am I reading too much into it?!!
 

 
 

 

[fluttermoth]

Most test kits are easier to read if;

you use sunlight rather than artificial
you look down the test tube instead of sideways
you hold the tube slightly away from the card, rather than touching.

 

[DrRob]

Ahhh, now you'll find that the behind the vial is for low reads to multiply by a factor of 10, below the vial is the normal read. That way you can read nitrites down to lower levels more easily.
 
As for lighting, if I remember correctly it says something like moderate daylight on the suggested readings, so yes, artificial will affect the reading, but then it'll do that with most kits.
 
Which kit is it? I may have one and be able to dig out the instructions and have a read.

 

[rms]

Most test kits are easier to read if;

you use sunlight rather than artificial
you look down the test tube instead of sideways
you hold the tube slightly away from the card, rather than touching.

 
 

Ahhh, now you'll find that the behind the vial is for low reads to multiply by a factor of 10, below the vial is the normal read. That way you can read nitrites down to lower levels more easily.
 
As for lighting, if I remember correctly it says something like moderate daylight on the suggested readings, so yes, artificial will affect the reading, but then it'll do that with most kits.
 
Which kit is it? I may have one and be able to dig out the instructions and have a read.

 Thanks both
 
I'm using Salifert, which does say low reads behind the 'vial' (thanks for the spell check btw)...  So on low reads should I multiply the result by 10? I'm confused because the low read is darker than the normal read (below the vial), so it seems to me that low reads tell me my nitrites are through the roof. Like, 10x0.25
 
I know it's me. Just can't get my head around the instructions...

 

[DrRob]

Ahhh, the wonderful art of communication, where what I type and what I mean don't necessarily match. Multiplication would be of the sensitivity of the test, not the result, so it's a divide by 10 for the result.
 
If you're viewing through the side and read 0.25, you're actually seeing 0.025. Thought it sounded like the nitrite test kit.

 

[rms]

Ahhh, the wonderful art of communication, where what I type and what I mean don't necessarily match. Multiplication would be of the sensitivity of the test, not the result, so it's a divide by 10 for the result.
 
If you're viewing through the side and read 0.25, you're actually seeing 0.025. Thought it sounded like the nitrite test kit.

Yep, that would make more sense. So the tank is in tip top shape then 

 Right I'm off back to school to learn how to read again. In the mean time thanks very much