help which test?

[don]

help! iam getting two different readings of nitrate, 6 n1 tells me about 40ppm, API reef master kit reads 0ppm,which one do i trust?

[Gz28]

I had similar problem with 2 different brands, not saying this is your case but the colors looked totally different under differnt lighting. i had swirley 6500k in one room 3500k in another bright white in another and a regular incadesant... i had to take both tests and look at them closely under each light until i found one that they looked the same... it was the incadesant or the swirley cfl 6500k daylight. This drove me crazy because on the one test it totally changed the results of the reading depending on what room i was in. it still drives me crazy now, lol. Not saying this is the case here but just something to throw out there if the colors are close together. I want an all digital test apparatus soooooo bad!
I probabally just made this worse for you, if i did i am sorry, just thought it "might" be worth mentioning...prob not though

[Gz28]

as far as which one is more accurate the api "should" be more accurate than the 6n1 dip strips.

[Gerwin]

Couple points,neither test kit is what i would call "top end" research grade tests.
So what do we do? We make sure we know we are using the test correctly, we are waiting the described time. Then we know what our target should be, normally 0. We can test known nitrate free water, if we get a 0 value and then use our test on tank water and get a positive reading then i would say you have some nitrates, are they 40?, again i like to think of these things as a rough reference not a absolute. And if we do so we know at least if we need to do some water changes etc. If you want a really good no3 test i have the salifert, it's about as good as you can get with out having to spend the really big money. I like the strips, they are fast and easy and they give you a close enough for what we need to know, sorta like good, ok, bad. And they seem to show 0 when used on ro water so they know what 0 is, any plus reading is straying from the goal.

And that's all i got to say about that.....

[don]

otay, thanks for the info, guess my next purchase will be a better test kit.

[phisher]

Also check the exp dates, most if not all have a limited shelf life.