Three test kits ... three different results

[RayD]

I tried three different test kits last night to test Nitrates and they all tell me something different.

Aquarium Labs = 0
Sera = 50! WAY in the red.
Tetra = 25

All three tests were conducted immediately after a 40 gallon WC on a 120 gallon setup. Maybe 100g total water volume, maybe even less.

Now of course I like the Aquarium Labs kit! It reads what I'd like it to read. I suppose I should bite the bullet and get an Elos kit and see what that one has to say.

My NO3 battle goes on. I will win!

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[Reefer140]

i hate that. ive had similar issues with tetra vs salifert

 

[snowmaker]

One of my biggest peeves... I've never had 2 kits have the same reading on the same parameter. Wouldn't be much of an issue if they were close, but sometimes they're way off.
Lately, I've been sticking w/ Salifert and trying not to think about it.

 

[Gonereefing]

since we are on the subject what is considered a quality reef test kit? I currently use Red Sea master reef. Was using tetra but changed it up. btw...was getting different reads as well from both kits.

 

[Joel A]

part of the issue is that no liquid test kit on the market is good at readings nitrates... good test kits (i prefer elos) tend to read the same on the big 3 (ca, alk, mag) which is all i even test for anymore... everything else is not worth it because good liquid test kits don't exist...

 

[afboundguy]

Ray is that nitrate reducing thing you got at AA making a difference?

 

[Reeferer]

How long did you wait before testing after your water change? I usually wait at least an hour for all the new water to mix with the old water. Also IMO you should pick a brand of test kits and use them all the time. This way you will have a "base line" to go off of. If you are always getting a reading of 25 with one test kit but your tank looks healthy than that is your baseline to go off of.

 

[Bobbofin]

Here's a good bit of advice. Do not use the marks on the test tubes to measure water amount. I always use a syringe to measure the water. You'd be surprise how much those marks are off! I found my tests were much more stable once I started doing that.

 

[dcforester1]

The marks on API kits are off by almost 1/4in

 

[Reefer140]

yeah i use syringe also

 

[RayD]

Ray is that nitrate reducing thing you got at AA making a difference?

Dave I ahevn't hooked it into the system yet.. You have to "feed" the reactor until the N03 reached zero in the unit then you can a** it to the system. I figure another week or so and the nitrates in the reactor will be at zero.

 

[RayD]

I just picked up the API test kit yesterday at AA. That reads 15.

 

[RayD]

Here's a good bit of advice. Do not use the marks on the test tubes to measure water amount. I always use a syringe to measure the water. You'd be surprise how much those marks are off! I found my tests were much more stable once I started doing that.

This response is worthy of repeating. I checked all of my kits last night and NONE of the marks on the vials are accurate. The API and the ELOS ones were way off!

Once I did some re-testing with the proper 5ml of water, things looked alot better. Thanks Bob for that!

So the API and the Red Sea kits measure between 0-2.5 on the Nitrates. That's livable. I can sleep now.

 

[dp28688]

thats worth sticky use of syringe for testing i never thought of that ill have to go get one.

 

[RayD]

I decided (with a little help from Mike and Patrick at AA) to go with the API nitrate kit. I also have the API CA kit that I bought when my Elos kit ran out and I was too cheap to buy another one!

The results are in. Matched the Red Sea Aquarium Labs kit. The Sera kit was WAY off the charts and I have to think that the Sera kit isn't good for my setup for some reason.

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[saltwaterB]

As mentioned above, there are really no good/accurate liquid test Kits for Nitrate. Personally I would not trust te API to be accurate for low levels of Nitrate. It may be a good indicator or general test, but definitely not accurate. For Nitrate I use Salifert, Elos, or even better Lamotte.

 

[RayD]

I've always had excellent results with Elos kits. I may try the Lamotte kit. Very pricey but may be worth it.

 

[saltwaterB]

That really depends on how accurate you really need it to be. Personally, Nitrates are usually not a big concern for me. If they get anywhere from 10ppm-20ppm, I just do water changes to keep them down. BUt I do not really keep any fussy SPS Corals.