cant figure out my nitrate.
 

using new red sea test kit for nitrate. as soon as i mix it- it shows ether 20 or 50. and 9 minutes later collor dont change.
using my old soon to expire api nitrate test kit. it shows 0 for nitrate.
ammonia 0 nitrite 0. no algae going on in my tank and some corals that i have looks good to me. fish not stressed out.

Do you trust a new kit, or an OLD EXPIRED API kit that we all know isn't very reliable to begin with?



I know which one I would trust.



And yes when I had high nitrates, the color didn't change much after the 9 minutes either. Now that my nitrates around .25, I don't see the slight color variation until the 9 minutes is up.

All of my API test kits are still accurate enough and all are expired 5+ years ago...
Anytime I do a test with my other test kits (Salifert/Red Sea,etc...) I always still do one with the API kits.. They always match even though API is expired years ago..

You need a 3rd opinion to know for sure.. Off to the local fish store with a sample of water you go..

Why? So they can use the same crappy API kit that will say 0. Never seen an LFS use anything but API. Yes they work, just not very accurate.



And personally, if your using a kit that expired 5 years ago and validating a well known reliable kit with it, you do not deserve to be giving advise on test kits.

I've been using both in tandem for years so that I can answer questions about the validity/accuracy of API test kits with actual hands on experience vs simply stating that a widely used test kit is just "crappy" like others that seem to just regurgitate the myths of others..
I'm not validating the well known kits.. I'm validating the API...

If the questions/concerns are over the accuracy of expired or near expired API test kits then quite frankly that puts me as more experienced than yourself to answer this question :frog:

Not regurgitating anything, used API for years, years ago as that was all that was available. Notice I did say they work, just not very accurate. My problem with the API kit(specifically the nitrate kit) it starts at 0 and the first point is 5ppm. Very hard to tell the difference in color and just not accurate enough for my needs.



Most reefers keep nitrates under 5ppm. What good would the API kit be if I keep my nitrates around 1 to 2 ppm?


And I would agree with you that even though API kits are expired, they still work just fine. Recently used an API ammonia kit I had to cycle a tank that was 2 years expired and read the exact same numbers as brand new kit.



I will stand corrected as the way you typed it out it seemed as though you were validating a new kit with an expired one.

Mine uses Red Sea for everything except phosphate. They use a Hannah checker for that. Actually two LFS near me do.

Either way I would get a third opinion. It’s possible the Red Sea has bad reagents though also possible the API is also bad. Registering 20-50 on Red Sea should not show a 0 on API, unless they register in different amounts like ppt and ppm. I would say a third test is in order just to narrow down which is bad.

All I can say is that I have been burned twice in the past by expired nitrate tests (one was Elos, don't remember who made the other). Both times the tests registered very little nitrate when in fact it should have been off the charts. Perhaps some types of tests are less susceptible to age than others, but nitrate isn't one of them.

I use the Red Sea kit, but usually test with salifert first to get an idea weather to use the hig range or low range instructions.

Try using 1 ml sample in 15 ro water.

thank you all very much for your comments. at the time when I was typing this thread i the api nitrate was still 0 but minutes later when I came back I wasent 0 anymore. it was more like 10-20 ppm. so bottom line is I spoke to soon and I do have nitrates in my system that I need to look into why. but yes I do agree I need 3rd opinion on this, since I don't know what is my actual number

sorry I'm not fully getting what you saying here.

With the Nitrate pPro kit you can measure high ranges of NO3 (4-64). For the sample you use 1 ml of tank water diluted in 15 ml of RO water. It should be on the flip side of the instruction card.

I'm using salifurt and API, only reason is I have no idea how to accurately compare the colors. Both read about the same.