API Nitrate Test Kit

[CoryDude]

Has anyone ever received false readings from this test kit?

I have an established reef tank w/healthy clams, lps, and sps and haven't had nutrient problems in years. So I was shocked when this API Nitrate test kit showed NO3 at 100ppm! I'm 99% sure that isn't right. Tank is completely healthy and I thought levels like that would be toxic to corals.

I know these are cheapo kits, and it was an impulse buy, but has anyone else ever received inaccurate readings from this particular test kit?

[tony]

they are actually pretty well known for that and are extremely temperature sensitive as to where they are stored

[CoryDude]

I should have expected something like that for $8. I didn't know about the temp storage item. All my equip and test kits are stored in the fish mechanical room that gets kinda warm during the day w/lights and chiller.

[clamgal]

I've never had problems with them. The only thing is reading the color for Nitrate results. I don't know if its my old age, but the 5 and 10 colors look the same to me.

[CoryDude]

I've never had problems with them. The only thing is reading the color for Nitrate results. I don't know if its my old age, but the 5 and 10 colors look the same to me.

It's not your age. You're right, the colors for 40ppm-160ppm aren't very different; Orange, reddish orange, slighlty more red w/orange, darker redish orange, AGGHHHH they all look the same!

I personally use Seachem kits and prefer the simple color change method to determine levels.

[CoryDude]

I need to offer an apology to API. I retested my tank w/a salifert kit, and nitrates are indeed high. Not as high as the API test indicates, but close. It doesn't help that it jumps from 80ppm to 160ppm w/nothing in between. These are good kits if you want a rough idea of your nitrates levels.

[wesheltonj]

I have read that the Salifert & API test for NO3 different. API measures total nitrate, Salifert measures nitrate-nitrogen. To adjust you divide API by 4.4 or multiply Salifert by 4.4.

But yes I have had a bad batch of API NO3

[ACE]

I recently had a bad API Nitrate test bottle. it read 20PPM no matter what tank I tested. I took a sample of the same water to B&B and he tested it and the same water tested at 0 for him.

[SABOB]

Also had bad readings with an API Nitrate kit.Aquarium Designs tested it at 10 ppm,my API was reading 200.API are fine for Calcium,Alkalinity but not for Nitrates.

[rz1a]

so if i had 80ppm reading on API, i divide by 4.4 and have 18ppm?

[CoryDude]

Also had bad readings with an API Nitrate kit.Aquarium Designs tested it at 10 ppm,my API was reading 200.API are fine for Calcium,Alkalinity but not for Nitrates.

I didn't like their Ca test kit. It kept telling me my Ca was in the 700 meq/L range. The lfs and Seachem helped me determine it was really around 450 meq/l.

Just FYI. Saw a posting on another SW forum and a rep from API admitted that the real problem w/their NO3 kits is the active testing agent in bottle #2 and the fact that it settles very quickly. He stated that even agitating it for 30 secs (as the directions suggest) may not be enough to get correct results.