Help with Nitrate Test

[nozleman]

Ok, very confused, Tested API and I get 20ppm
Tested with Salifert I get .5 ppm
Just bought the Salifert kit today, Api is about 4 months old? NO clue which one is right? Any help will be welcomed, thanks

[KSzegi]

Following along to see comments about which nitrate tests might be most accurate. I ran nitrate yesterday with an API and a Red Sea. Red Sea test showed 2.5 ..... and API showed a 20 on my 180. Both showed zero on my 90. So, ok zero we can agree on but the other is a major difference!

[RegalAngel]

Ok, very confused, Tested API and I get 20ppm



How are you looking at the API test tube? Down thru the top or from the side?
Salifert is viewed thru the top while the vial is sitting on the white part of the card for medium resolution.

[nozleman]

Did exactly what the directions said, first top down, and since it was less than 10, from the side next. Anybody with help or experience, thanks!

[Chris27]

Did you shake the API Test Tube for 30 sec? Also, check the lot number to ensure the kit is less then a year old.

[nozleman]

yes checked API is less then a year old. Went out today and bought a tetra test kit. It read 25 ppm almost what the API read, pretty close! How can the more expensive test kit and the better test kit read so wrong??

[HighlandReefer]

Without comparing your test kits using a nitrate standard in the range you expect, you really can't tell which is the most accurate.

Hach sells nitrate standards:

http://www.hach.com/hc/search.product.details.invoker/PackagingCode=30749/NewLinkLabel=Nitrogen-Nitrate+Standard+Solution+as+NO3-N+(NIST),+10+mg%26frasl%3BL,+Bottle%26frasl%3B500+mL

[RegalAngel]

Exp. date of Salifert? If less than 6 months, get a newer one. I had a Salifert Nitrate that was bad even with 6 months left before Exp.

[bertoni]

I agree that the nitrate standards are about the only way to be sure. What animals are in the system, and is there a problem you're trying to solve? We might be able to help, without spending money on the standards.

[nozleman]

oh ya! Sps tank and all look horrible! Heavy fish load, 140g 150lbs live rock, refugium w/cheato and live rock, DSB, chiller, skimmer, uv, ozone, 400w radiums, calcium reactor, ro/di water with new filters, all on ACIII.

[bertoni]

I would measure the phosphate level, and check all the basic parameters: salinity, temperature, calcium, alkalinity, and maybe magnesium, and make sure all the tests were reasonably accurate. A second opinion might be useful, for example.

I'd probably stop feeding for a few days, and see how the tank responds.