Question re: testing kits

[Alestro Bakai]

First time poster, long time troll.

Here's my question... I have a liquid test kit and a strip test kit.
In my main tank I get almost zero Nitrate ppm with the liquid test
kit (tested 4 times) The strip tells me 30-40 ppm. So I thought
that the liquid test kit was simply too old or what not, but before
I tossed it, I did a test on my secondary tank and I got a 20 ppm
reading.

What's the deal? Any suggestions?

 

[kveeti]

Did you also try out the strip test for the secondary tank - how did that compare? I've read that strip tests weren't the reliable ones but don't have any experience with them. The liquid tests can also be inaccurate if they are older. What I would do is take a water sample to a fish store and get their result. They usually test for free. Get an actual number, don't let them just tell you it's "ok". Just for something else to compare to.

Welcome to Aquaria Central (and p.s. better to say long time lurker than troll)

 

[Roan Art]

Most nitrate tests, strip or liquid, are not correct. In order to get an accurate reading on nitrate, you really have to purchase field grade tests, which most of us cannot afford.

As an example (these are all examples of liquid tests), when I test my 75g Boesemani tank -- and I KNOW the nitrates are 0, just ask the cyanobacteria that live there -- the Aquarium Pharmaceuticals test will tell me it's about 7.0ppm. When I test it again with the Hagen nitrate kit, it tells me it's awaywhere from 50-100ppm :laugh:

FWIW, the AP test is more accurate, but it's not perfect.

Roan