Nitrate confusion

[GraviT]

Since I started my tank, I've been using the Aquarium Pharmaceuticals 'Saltwater Master Kit'. I've noticed that this test seems to be inaccurate, as it always measures between 40 and 60 ppm, even shortly after a water change. Frustrated by this test, and unable to understand why my fuge isn't helping, I went to the LFS and purchased a FasTest kit. This one reads 10ppm.

Now, the confusion....the AP test states that the results from that method will measure 4.4 times HIGHER than tests that measure nitrate-nitrogen (which includes the FasTest). Question is, which test should I follow? Obviously, 10 ppm is much more desirable than 40 in a reef environment. [smiley=freak3.gif]

[GraviT]

Shameless bump..certainly one of you guys have encountered this and have an opinion!! [smiley=crazy.gif]

[JohnO]

Gravit,

Sorry mate can't help as I don't know those test kits :-)

I have always used Salifert as I belive they are the most reliable.

John

[Jason McKenzie]

It sound as though the AP tests are not refined enough to measure just the elements that are harmful to marine life. I would definitely switch tests and I would switch to Salifert IMO

J

[GraviT]

Thanks for the input. I've switched to a SaliFert test and it reads <10 mg/l. Guess my 'fuge is helping after all! [smiley=biggrinbounce.gif]

[Craig Manoukian]

Test kits are truly the essence of you get what you pay for. The higher cost is directly tied to higher accuracy. I have gone from Salifert to LaMotte for that very reason. Glad you are getting better readings and your refugium is contributing to lower nitrates!

[somethingfishy]

I have used AP test kits with my fresh water and had no problems so of course I bought their salt kit. I haven't had any problems with it yet. I think I will do a comparision with my friends test kit (if she lets me) and I will post the results. I believe she uses fast test Kits, not 100% sure.