API Nitrate test completely unreliable!

[FishGuy67]

I've done as instructed even using a stopwatch for the 30 sec and 1min times you should shake the bottle. Yet in my cycling log I have from march 12th or so looks like this for nitrates 5,5,5,5,40,40, now I redid the test 3 times and I'm getting 5 everytime. Nothing changed between my last reading of 40ppm to this one no water changes etc.

Is there some secret way to get accurate tests? What the hell am I doing wrong.

[Knightia]

How old is your test kit? They have a shelf life.

[Cliff]

Shake the bottle like your life depended on it

If I really really shake those bottles hard, I find I get accurate results. A light shaking typically will not due

Have you checked the experation date on the bottle yet ?

[FishGuy67]

I have over 4 years left on the expiration.

I shake it like my life counts on it with a timer for bottle 1 and 2.

Could it be how I fill it up using my thumb to hold the bottle top and let it drip out til I'm at the line? Perhaps the fact I clean em in tap and let them air dry? All the other tests are spot on and I do the same thing.

A better question is I'm 3+ weeks into cycling so are all the 5ppm results correct and the 2 40ppm results wrong?; actually was 10 or so this time every time I did it today I got 10-15ppm.

[FishGuy67]

I'm in the Nitrite spike stage now so my nitrate should be somewhat high even with the water changes I do no?

[mommy1]

It could also be the way you are holding the reagent bottles, they have to be perfectly straight so the drops are uniform in size, or as close to uniform in size as you can get them.

Every cycle is different, some have high nitrates some don't, same with nitrites.

[FishGuy67]

I'm going to do it 2 more times and see with all the advice if I get accurate readings.

[FishGuy67]

Okay following all the advice (thank you all very much) I got 7.5 both times. So mostly likely the 2 40ppm readings were wrong. So its basicly 5,5,5,5, then 2 misreads of 40ppm and now 7.5 which seems about right.

Like i said I've been keeping logs since march 11th (been cycling since feb 25th) or so when I got my master test kit; you know water changes when I added filter media from my pet shop which they were nice enough to give me 2 large pieces. So I really hope I can order at least 7 corys by the 1st of next month.

It really sucks having the lights and substrate etc for a planted tank with a koi who loves to rip plants up.