Are Nitrate Tests a Joke?

[Kasey Grohowski]

I've been testing consistently with Red Sea and Salifert since my tank completed it's cycle (6 months ago), and I get the same as I got back then. Salifert shows 10-20 and Red Sea shows ~20ppm. About a month ago I added a bigger protein skimmer, carbon, and refugium. I noticed a huge decrease in cyano and hair algae that was in my tank, yet nitrates haven't moved a bit. Anyone else experience this?

 

[jda]

Yes. They are just a swag. If you want one that is more precise, they are several hundred dollars and hard to find - most of these are Cadmium Reduction method and can also be somewhat unreliable with excess chloride ions in the water.

I do like Salifert the best, but I only use it to see if I am "clear" or not. I cannot even get any color looking through the side at 10x range. ICP says that is .1.

Most nitrate in new tanks is from a lack of anoxic regions in the sand and rock that house bacteria that turn no3 into nitrogen gas. These can take a while to develop, especially if you used dry/dead rock and don't have much sand.

 

[Aardvark1134]

Saltwater is hard to test nitrate in. You can honestly get just as good of a guess from API as the expensive ones. When it comes to nitrate in saltwater you mainly get 3 readings...almost none, some, or lots. As long as your test can tell those 3 apart you will be fine.