Which Test is right?

Hi guys I have two kinds of tests for Nitrate as you can see on the picture. But there is a 15ppm difference between them the one on the right is the on one I was using for a while now and its for fresh/salt water. The one on the left I got a week ago the Fastest This is the one that reads about 5.0 and the one on the right says 20 which one is more accurate?

 

Test kits as you have just found are hit and miss some times. depends on how old they are and you can get a bad one which does not mean all from the same company are bad. Take some water to the LFS and have them test it and see if it match's one of your test kits. If it does then use that one and see if the place you bought the other one will swap it out.

 

We ran into a similar problem in our tank. We have the aquarium pharmaceuticals (the one on the right) and a red sea test. The Aquarium Phamaceuticals test runs about 20 ppm and the red sea test runs between 2.5 and 5.0 ppm.


I think the answer lies within the fine print ... Looking into the fine print of the Aquarium Pharmaceuticals test ... the insert says ...

"THis test kit measures nitrate as nitrate ion or "total nitrate." Other nitrate test kits that measure "nitrate-nitrogen (NO[sub]3[/sub]) will give readings 4.4 times less than this test kit."


We take this to mean that the aquarium pharmaceuticals test is really measuring a lot more than other test kits so that's why the results run higher. But its still a bit confusing ...

Any experience or input?

 

The RO water that I'm using reads 0 on both of theme so it means that aquarium pharmaceuticals test is better like low range Nitarte test?

 

Well they're two different things here.. Verbal nailed it.

Check this out:

http://www.aquarium.net/996/996_4.shtml

 

so which one is important? some people say that they try to keep theirs at .25 ppm
so do they mean 1.0 or .25 and what should I keep it at if I have corals? I mean what is the acceptable level and which one is important? when they say keep it at .25

 

ppm is the nitrogen-nitrate reading (not the total nitrate one) and is more commonly used by far.

Total nitrate uses millileter per litre or something like that.

If someone is shooting for .25 ppm, I don't know why they don't just shoot for zero. Anything under 10 ppm is pretty darn good in my book and shouldn't cause you any problems.

Fish can tolerate a heck of a lot more nitrates than corals. And, in my experience, things go south over 20 ppm. Most fish seem to take a hit over 40 ppm.

 

but you are talking about the ppm reading right not the total? so Less than 10 ppm is ok

 

and you guys were right the one on the right tests the "Total nitrate" just found the istruction

 

Yeah less than 10ppm is great.