Hello, some of you might have been reading my thread about Droncit, which has in turn led to a discussion on Nitrate levels in my tank, upgrading etc.

Well, I was out today looking at tanks and I decided to buy a Nutrafin test kit for Nitrate, as I had been getting a reading of almost 40 using the API test kit for my tank. I am slightly overstocked and am aware of this, which is why an upgrade is planned asap. I had just done a 50% water change to reduce the nitrate level of 40 to 20. I tested the water using the Nutrafin test kit straight after I'd finsihed the water change........I got reading of 5!!!

What is going on? I seem to be getting a huge difference in the Nitrate levels between the 2 kits! Which one am I to believe?! I am going to do a side by side test tomorrow with the 2 kits and see what I get then a day after water change. But if I get a low Nitrate reading again on the Nutrafin kit, then I won't know which one to believe. If my Nitrate is 5, it also means I've been worrying myself about nothing!

Has anyone else had similar discrepancies between these 2 kits? Is it worth testing our water at all in this case?!

Hi,

Did you make sure you shook the reagent bottles very well, having stood on a shop shelf for weeks on end they've probably settled and may give a false reading.

Jay

Hi Jay, I followed the instructions very carefully on the Nutrafin kit, and it only instructed to shake bottle 3.

Where is the use-by date on the API kit by the way? I looked for it today but couldn't find it! I only bought the kit over the summer so it's very unlikely to be out of date, but just wanted to check it was still in date.

I'm thinking about buying the Nutrafin mini-master kit now to compare all the tests!

Each API reagent bottle has a lot number, the last 4 digits are the year and month that it goes out of date.
For example; 1007 means July 2010.


I would retest giving each bottle a good shake prior to using them & shake the test tube well too.

I've had a similar experience with different kits giving different results - did a bit of a trial ages ago

http://www.fishkeeping.co.uk/modules/ ... ASC&type=&mode=0&start=30

The Hagen/Nutrafin one was definitely not a winner IMO. I use the Tetra one now after having used the API one for ages.

Just to add, the nitrate test is more likely to give a false low than a false high reading, suggesting it's the new one giving the duff result. If the reagent bottle that needs shook has been sitting on a shelf for a long time then it will need shook really hard, and possibly gently knocked off a hard surface to get the 'ingredients' back into solution as they will start to solidify when it is just sitting there. If you're using it regularly than shaking it for about 30 seconds will do but for a new bought test I would try shaking it for a lot longer, probably more like 2 or 3 minutes.

I got this information from a thread on another forum here: http://www.fishlore.com/fishforum/tes ... aster-test-kit-users.html as I was having problems with 0 nitrate results when my tank first cycled months ago.

It also says that the numbers on an API kit are the date of manufacture and each one has a shelf life from that date. Don't know if they've changed that now? But it's all in that thread if you have a read of it.

Lisa

Thanks very much for this Squish - interesting reading. And thanks for the other link to that thread. So, perhaps I should trust the API kit then? But it's difficult, you know?! I want to believe the one that reads 5! But I know this might be a false low reading! Will test with both tonight for Nitrate and see what I get.

Looks like the tank upgrade is still on then! :D

I would trust the API Freshwater Master liquid test kit, it was both highly recommended on PFK and on this forum too, plus numerous other sources I've read.

I wouldn't panic too much about NitrATEs if I were you, the J&H book says nitrATE under 50 is ok, but ideally of course you want it under 20. You know why you have the higher reading, but I don't think it's affecting your fish.

The J&H book gives good reading about nitrATEs and how it affects fish when it's constantly too high, eg can cause buoyancy issues in fancy goldfish. But you know this already. So just keep looking for that dream tank, and make sure nitrATE is under 50, but preferably under 20. I know you'll do your best to ensure this, you're a great fishkeeper Miss P! :D

Here we go, knew I had the correct information somewhere regarding API test kits..

Each reagent bottle has a Lot # printed on
the bottle. The last four digits are the month and year of manufacture.
Example:
Lot # 28A0107. This is a pH reagent manufactured in January of 2007.

Pond Care Wide Range pH, Ammonia, High Range pH, Nitrate, Phosphate, Copper, Calcium and GH all last for three years.

Nitrite and KH will last for four years.

Freshwater pH (low range) and Pond Care Salt Level will last for five years.

Jay

So tested my Nitrate levels again tonight and got the following;

API - 20-30 (not as light as orange 20, but not as dark as red 40)

Nutrafin - 10

Take the average?!!! Who knows! Plus, in a house with energy saving lightbulbs it's really difficult to match the colour chart!!