Reading nitrates / Dr. Wellfish

[riscchip]

Greetings,

I've learned a lot of great things reading this forum, but this is my first post. Apologies if this question is covered elsewhere, I did try searching around a while.

This may be a bit of a silly question, but here goes...

My question is about the Dr. Wellfish nitrate test kit. The manual says to hold the test tube up against the card to compare the color. Are you supposed to hold the card directly against the card, or just in front of it.? The color is completely different based on whether or not the tube is touching the card. If the tube is touching the card, it blocks some light hitting the card and makes the reading appear much darker.

Thanks to anyone who might know this one.

--Carson

[AABatteries]

I read mine against the card, I held it away and its a little different, the instructions show it right in front of it so I took it as touching it.

[riscchip]

Thanks my friend! I just wasn't sure if you were supposed to let a little light in behind the tube or not. Much appreciated.

--Carson