Evaluation of NO3 test kits

[geoffrey]

Recently I bought a new Sera NO3 kit. It tested >40ppm of NO3 in my tank. I knew this was not possible. So I decided to try with 2 other test kits with a known ppm. Here's what I found.

NOTE: Test solution is made from 1 drop (assuming 20 drops to a ml) of KNO3 from a 82g/l stock into 500ml of tap water.

Hagen-Nutrifin
3 reagents were needed. All liquid. The third reagent was particularly difficult to administrator into the narrow vial. Matching of test sample with colorimetric chart ambiguous and difficult. Although test sample read 5ppm but this was done looking from the top of vial against the chart instead of the recommended method. Using the recommended method will mislead you to think you have 0ppm. Price moderate for a fancy packaging and accessories.

Dupla
ONLY 1 powdered reagent was needed. Reagent expires 12 months after opening. Easy to use. Those attuned to 5ppm and 10ppm may find it difficult to adapt to 3ppm and 10ppm range in their colorimetric chart. Sample required is an odd 12ml instead of the standard 5 or 10ml required by other test kits. Registered NO3 between 3 and 10ppm albeit with some difficulty matching with a teeny weeny piece of color chart. Expensive for a frill-less packaging.

Sera
3 reagents used. 2 liquid and 1 powdered. Good colorimetric chart for matching but unfortunately sample readout was way out on the high side - above 10ppm. Tested a second time with much lesser reagent 2 (powdered) and reading lowered to between 5~10ppm. Reagent 2 seems to vary the accuracy of the test kit over time. Moderately priced.

I would really hope to see some feedback on JBL, Tetra and AP.

[heavenhell]

Hi, just bought AP NO3 test kit from C328 today, tested my water it showed 10ppm. I think quite accurate cos just add 10ppm Kno3 to water. The color difference quite obvious n in interval of 5,10,20,40,...

[PeterGwee]

I have experience with JBL and tetra...both failed badly though. I rather dose the estimative index way and back off on the KNO3 slowly till I get the colour I want from the plants and maintain regular feeding for some pulses of ammonia and NO3. Works much better imo/ime.

Regards
Peter Gwee

[CT]

So anyone else use b4 the AP NO3 testkit? how's it when compared to other brand such as sera and jbl

[anaconda]

Just bought a Sera NO3 test kit. Tested my tank with it...it showed 40 .way over the safe limit..been getting BBA bloom recently so I figured it might be correct. Test tap water with the test kit, it shoulded about 0 which is correct

so did a 60-70% water change. waited 1 day, tested the tank water again. Again it showed 40!!

What do you guys think? Either my fishes been shitting a lot or the test kit is way off

I am keeping small fishes. None of them above 3 cm in size , got about 50 of them in a 2x1.5x1 tank

ANyone know where else to get the AP kit? C328 ran out

[CT]

wah so fast run out already! went to C328 on thur to buy my pH kit, still have NO3 testkit on that day.

[Sleepy_lancs]

I got mine from Serangoon North. Petmart has it.. if you walk a little further another store has it too...

[eric_kclee]

Bedok North 'Pian Yi Dao Xiao' no more stock already...I bought the last AP-NO3 test kit.

[anaconda]

Hows your experience with the AP NO3 test kit? Is it accurate?

Sera has been giving me nothing but 40 everytime i test it

[eric_kclee]

[quote:05c8a2e36e="anaconda"]Hows your experience with the AP NO3 test kit? Is it accurate?

Sera has been giving me nothing but 40 everytime i test it[/quote:05c8a2e36e]

The problem is, which brand is accurate? There is no standard to compare with.

What I know is Serra has 3 component, the second component which is a powder, the amount to put itself is very difficult to judge and very difficult to be consistent each time and yet it is the critical component which will affect the result...so how accurate can it be.

For AP, only 2 bottle of liquid, count by no. of drops...and I manage to get consistent result for repeating test.

However, AP test kits lot to lot or batch to batch consistency has not been tested yet.

[toledosun]

[quote:957a5ecf38="anaconda"]Hows your experience with the AP NO3 test kit? Is it accurate?

Sera has been giving me nothing but 40 everytime i test it[/quote:957a5ecf38]

trsy shaking regents 1 & 3 before adding them into the water. Same thing happened to me. if you shake the two bottles first, your results should be more accurate.

[Plantbrain]

I've been around a few times on this issue, for NO3, a Lamott or Hach kits are good at accuracy at low ranges.

www.aquatic-ecosystem.com sells all sort of stuff, you can also bother Lamott and Hach about distributors.
The refills are relatively cheap.

Testing the Tap water or asking them for the levels and then assuming it to be true and dosing with KNO3 will get you to about 1-2ppm accuracy, but if you want to look at uptake rates etc, you'll need a kit.

Also don't forget about denitrification lost potentials.

Regards,
Tom Barr