Where Have My Nitrates Gone?

[Lazerus]

Hi all,

For the past 8 days I've been leaving my tank without any water changes as my tank appears to be cycled now after about 2 months and I wanted to make absolutely sure by leaving it alone.

So, for the last couple of days my readings have been:
Ammonia: 0ppm
Nitrite: 0ppm
Nitrate: graduating from trace amounts up to 5ppm as each day went by.

This morning I did my test and my Nitrates are back at 0ppm.....so where have they gone?

I've done nothing different to the tank, other than add their small daily feed as usual.

I'm confused.

 

[Corleone]

What test kit are you using? The API nitrate test is kind of finicky. It has some apparently pointless steps, like shaking bottle 2 for a full minute and shaking the tube between bottles. I've found if I skip a step or get sloppy, I get low readings.

Aside from that, it's unusual, but it is possible in some circumstances. It's a bit more likely if you don't have many fish yet, particularly with a good stock of plants (or algae).

 

[Axleuk]

What test kit are you using? The API nitrate test is kind of finicky. It has some apparently pointless steps, like shaking bottle 2 for a full minute and shaking the tube between bottles. I've found if I skip a step or get sloppy, I get low readings.

Aside from that, it's unusual, but it is possible in some circumstances. It's a bit more likely if you don't have many fish yet, particularly with a good stock of plants (or algae).

This is the first time i have heard that the Nitrate test is finicky. I was under the impression that the API Master Test Kit was one of the more superior and accurate testing kits. Which is why it comes highly recommended by forum members.

I have contacted Aquarium Pharmaceuticals regarding these steps via email and await there response. I would be interested to find out why these steps are nessecary and i am sure our fellow members, including yourself would be also be interested in their explanation.

In the meantime, i believe i have found the answer on the 'net' from a member of another site who posed the same question to API and had the following response.

Liquid Nitrate Test Kits from any manufacturer can have a common problem
with their last test solution. For some companies, it is bottle number
3, but for us it is bottle number 2. One of the ingredients wants to
solidify out of liquid solution. If the test bottle sits for any period
of time, this can happen. If this does happen and the test is performed
without Bottle # 2 mixed properly, then you can get a falsely low
reading. I have never heard of falsely high readings with Nitrate Kits.
I would try tapping your Bottle # 2 a few times on a table or counter
top. This should loosen-up anything that has solidified. Then I would
shake this bottle for about 2-3 minutes, to really mix it up. Try the
test again and hopefully this will fix your problem. With regular weekly
usage, this bottle should only need to be shaken for 30-60 seconds.

Always check results at the recommended duration of time. Letting the
tubes sit longer can result in falsely high levels."

I think this explains to people why shaking the bottle is an importnt step in getting the most accurate results. Its also important to read the instructions.

 

[waterdrop]

Hi Axleuk,

Yes, you are finding the right stuff I think. My father-in-law is an organic chemist and went over the tests with us when we first were learning them. He emphasized that liquid test kits for Nitrate have always been very, very hard to design and that probably the times given for shaking were held down to the shortest possible times by the product sales person, not the chemist, who probably would have said to stick it on a powerful shaker machine and let it go for a decent time!! The upshot of which is that he said to absolutely do all the shaking in the instructions and be as energetic as possible about it!

This stuff we are saying has been reported pretty often on TFF and it makes sense to me that on the forum we see quite a variation in results people have partly because their behaviours with respect to following the instructions and with how much the stuff in bottle#2 has become stuck probably vary a lot.

So anyway, my summary of the API kit would go as follows: pH & High pH tests work fine but then pH tests are quite easy for any company to get right. API ammonia and nitrate tests are great and are perhaps the best of the different companies in peoples ability to discern different levels via the color variations. Nitrate test more unpredictable, but probably because making a cheap non-electronic test for that has maybe always been pretty difficult.

One of the reasons I think TFF has settled into the API kit as much as it has is just the simple convenience of everyone's then being able to chit-chat about the colors of their results and be speaking a common language among one another. In other words just kind of a default standard, and not because the API is really any better than say the Nutrafin -- in fact some of the Nutrafin tests may be considered more accurate in some cases. And then there the Salifert tests which I believe are very respected as some of the most accurate of all, if perhaps a little more complicated and possibly more expensive and a little more oriented to marine use. There are definately cases where experienced members will direct one toward a Salifert test or a TetraTest test for some particular case under study.

So I think a big part of the API popularity here has to do with both "quite consistent quality", "a good enough tool for the purpose" and finally "a common lingo" making for easy communication among members.

~~waterdrop~~
ps. re this thread - I'm remembering this as a small tank, very few fish (& plenty of live plants?) - which could definately play into small amounts of nitrate production which then are taken up by the plants (plants taking up ammonia usually as first choice, but then also taking up some nitrates, especially if not as much ammonia present.)

 

[Lazerus]

Hi again. Sorry....I meant to come back the other day but ended up going away for the weekend!!

Well, my nitrates are still at 0pmm after 11 days without a water change....I did a water change anyway as I felt the tank needed freshening up. (My ammonia and nitrite were 0ppm also)

And just to confirm, I am using the API master test kit, and I assure you I follow the instructions to the 'T' ....I'm a bit of a perfectionist these days when it comes to the shaking the bottle no.2 & test tubes according to the times, and then timing the contents etc.

My tank is a 10gal with only silk plants. resin logs and gravel...I have 6 Cardinal tetras in there nothing else.

Also, the tank is completely clear of Algae...I did have an algae problem about two weeks ago, but I've been keeping it at bay now by cleaning the decorations every few days....the algae does not appear to be coming back now though anyway.

I just thought it was an odd thing to happen as I was getting Nitate readings, then I suddenly, I wasn't

I am now still unsure if my tank is cycled or not?

 

[Corleone]

If ammonia and nitrite were 0 and the fish were healthy with 11 days and no water changes, it's probably cycled. Continue with weekly water changes, even with no nitrate - there's other things that happen in the water that aren't tested for which water changes also deal with. Nitrates are usually used as an indicator of how far those things have progressed, but in your case it can't be. With fresh water, changes so cheap as to be free, so more is better, IMO.

I wonder if one of the test bottles has gone bad somehow. If you can, take two samples of water, test one with your kit and take the other to the LFS and have them write down the numbers they get to compare. If anything doesn't match, replace that test (You should be able to find the API tests individually packaged - I replace mine that way) and try again.