Ammonia and Nitrite wont quite go to zero

Incredible-bulk

New Member
Joined
Mar 11, 2022
Messages
6
Reaction score
0
Location
UK
Hi.

I have been doing a fish in cycle of my 54litre tank which has 3 corrys and a beta in. Ammonia and nitrite levels rose steadily and then dropped sharply very suddenly one day. Down from approx 2ppm ammonia to around 0.3ppm. Nitrite similarly down from almost 400ppb to around 40ppb. However, the readings have remained stable around that for around a week and dont look like going to zero. Below are a few readings from said tank which are just a sample. The tank has been running for approx 2 months.

23/2/22

Ammonia 0.53ppm
Nitrite 71ppb
Nitrate 0ppm
pH 7.4
TDS 328ppm
Alkalinity 70ppm
GH 161.1ppm

24/2/22

Ammonia 0.57ppm
Ammonia 0.45ppm

27/2/22

Ammonia 0.65ppm
Nitrite 179ppb

1/3/22

Ammonia 1.06ppm
Nitrite 229ppb

2/3/22

Ammonia 1.10ppm
Nitrite 397ppm
Nitrate 0.9ppm
pH 7.3

4/3/22

Ammonia 0.97ppm
Nitrite 246ppm

5/3/22

Ammonia 1.12ppm
Nitrite 232ppb

6/3/22

Ammonia 0.37ppm
Ammonia 0.35ppm
Nitrite 89ppb
Nitrate 0.6ppm

8/3/22

Ammonia 0.33ppm
Ammonia 0.29ppm
Nitrite 44ppb

10/3/22

Ammonia 0.27ppm
Nitrite 42ppb
Nitrate 0.9ppm
pH 7.3

The tank has been running since december but i was previously doing 50% water changes almost daily in order to control ammonia to approx 0.2/0.3ppm but i was getting nowhere in terms of a cycle. No nitrites and no nitrates. So i decided to stop the water changes and just dose with prime daily. This appeared to work, ammonia and nitrites rose and then dropped drastically one day, but they havnt reached zero.

Any advice welcome. Cheers.
 
40 ppb = 0.04 ppm which is so low that most test kits can't read it. The lowest most test kits can read is 0.25 ppm. I would consider that to be as good as zero.

What are you using to test ammonia? If it is a salicylate liquid tester, what kind of light are you reading it under - daylight, fluorescent, LED etc?
 
Hi thanks for the response.

All parameters measured with a hanna aquaculture photometer. I have occasionally run the ammonia tests more than once because i havnt always believed them but tests have come out within 0.05ppm of each other as you can see.
 
I suspected you were not using liquid testers with your nitrite results being in ppb rather than ppm :) The reason I asked is because salicylate testers can give inaccurate readings in some lighting conditions, mainly fluorescent lighting.

Since your nitrite is so low, I think you can ignore the ammonia reading. That usually drops to zero well before nitrite. But if either of them start to increase, then is the time to take action.
 
Yeah i am spoilt having such test equipment from when i used to keep a koi pond. A lot of things have baffled me to be honest. When you say ignore the ammonia reading, are you suggesting this is a fully cycled tank? The ammonia and nitrite have dropped significantly and stayed dropped, albeit not zero. Although i take you point about 40ppb being basically zero lol. I have very minimal nitrates. I dont know whether to be concerned about that.

Edit - i have just cleaned my gravel substrate and it was absolute filth, so that may account for the ammonia?
 
The dirty gravel may well be a cause - keep testing in case disturbing it causes a spike.

Yes, I am suggesting the tank is cycled despite the reading for ammonia. That should drop to zero quite a while before nitrite does and as your level seems to be stuck as ~0.3 ppm, I think you can ignore it. But if it does start to increase - or nitrite - then treat it as uncycled.
Using your figures in a free ammonia calculator and assuming a temperature of 25 deg C, the free ammonia level is 0.0043 ppm. Fish are safe for several days at 0.02 and your level is well below that.


I assume you know about free ammonia/ammonium from when you had koi?
 
I just spent about half an hour researching the Hanna Aquaculture Photometer. I was most interested in the nitrite section and I downloaded the manual. It reads nitrite in two ways both of which are in mg/l which is equivalent to ppm. There is nothing there about ppb.
8.16. NITRITE HIGH RANGE
SPECIFICATIONS
Range 0 to 150 mg/L (as NO2‑)
Resolution 1 mg/L
Accuracy ±4 mg/L ±4% of reading at 25 °C

The two ways it will measure Nitrite, as well as ammonia and nitrate is first, on the Total Ion scale, and it then allows one to convert that to the Nitrogen scale with a button push. Those of us who can not afford the Hanna Aquaculture Photometer do this math in about 10 seconds manually with the conversion chart found here https://www.hamzasreef.com/Contents/Calculators/NitrogenIonConversion.php

As a result I do not believe the nitrite numbers you reported. Further I do not believe you indicated which of the two scales you were posting. When it comes to Nitrite some of the levels you posted should have killed your fish if in mg/l or ppm on either scale.

Next, measuring nitrate is extremely difficult. Normally it is done by reducing it to nitrite and reading that. If one has nitrite in a tank it will throw off the nitrate reading. So when you report nitrite but no nitrate, I am dubious without knowing more.

As for ammonia levels here is what your manual says in section 8.3. AMMONIA HIGH RANGE about what might interfere with results {red is added by me)
INTERFERENCES
Interference may be caused by:
Acetone
Alcohols
Aldehydes
Glycine
Hardness above 1 g/L
Iron
Organic chloramines
Sulfide
Various aliphatic and aromatic amines

An example of an Aldehyde we might have in a tank would be Flourish Excel (basically glutaraldehyde) or SeaChem Paraguard "ParaGuard™ is the only fish and filter safe aldehyde based parasite control product available (for parasites on fish)."

If you could clarify your numbers a bunch it would help a lot. My guess is when you keep get continuous very low ammonia readings (in the 25 ppm range on the total Ion scale) they are due to interference or testing error and not actual ammonia.
 
That is for nitrite high range test. Nitrite low range is measured in μg/L not mg/l. I am confident in the test results.
 
The dirty gravel may well be a cause - keep testing in case disturbing it causes a spike.

Yes, I am suggesting the tank is cycled despite the reading for ammonia. That should drop to zero quite a while before nitrite does and as your level seems to be stuck as ~0.3 ppm, I think you can ignore it. But if it does start to increase - or nitrite - then treat it as uncycled.
Using your figures in a free ammonia calculator and assuming a temperature of 25 deg C, the free ammonia level is 0.0043 ppm. Fish are safe for several days at 0.02 and your level is well below that.


I assume you know about free ammonia/ammonium from when you had koi?
To be fair, i had totally forgot about free ammonia and total ammonia. I never had an ammonia issue keeping koi. I had massive filtration and my biggest issue was keeping nitrate under control because the nexus filters were nitrate farms.
 
My mistake. I assumed you had the model of Hanna Aquaculture Photometer that was less expensive and did not do low range nitrite testing. I assumed you did not have the priciermodel HI83303. My bad, I apologize.

So I would agree the nitrite level is not enough to matter for the fish. In fact, given the sensitivity of the Photometer I would bet what it is reading is the presence of the minute amount of nitrite that actually exists in the water before being taken up by the nitrite oxidizing bacteria. HobbyThis also means there is little effect on the nitrate readings from that concentration of nitrite.

But I am still curious about which scale you were using- Total Ion or Nitrogen. This matters if the ammonia numbers.

However, I should have read your posts even more closely than I did because here is what I just discovered in the rereads. You wrote, "So i decided to stop the water changes and just dose with prime daily. This appeared to work,"

I also checked out the reagents for the mid-range ammonia test for your Photometer. The test uses the Nessler method not the Salycilate one.

Medium Range Reagents (100 tests)

The HI93715-01 are high quality reagents that are pre-measured, allowing for users to achieve fast and accurate colorimetric measurements. These reagents follow the Nessler Method in which the reaction between ammonia and the reagent causes a color change in the sample.
https://www.hannainst.com/hi93715-01-ammonia-medium-range-reagents-100-tests.html

Next, on SeaChem's site in the FAQ section for Prime you will find this
I am using Prime® to control ammonia but my test kit says it is not doing anything, in fact it looks like it added ammonia! What is going on?

A: A Nessler based kit will not read ammonia properly if you are using Prime®... it will look "off scale", sort of a muddy brown (incidentally a Nessler kit will not work with any other products similar to Prime®). A salicylate based kit can be used, but with caution. Under the conditions of a salicylate kit the ammonia-Prime® complex will be broken down eventually giving a false reading of ammonia (same as with other products like Prime®), so the key with a salicylate kit is to take the reading right away. However, the best solution ;-) is to use our MultiTest™ Ammonia kit; it uses a gas exchange sensor system which is not affected by the presence of Prime® or other similar products. It also has the added advantage that it can detect the more dangerous free ammonia and distinguish it from total ammonia (total ammonia is both free ammonia and non-toxic ionized forms of ammonia).

So I am wondering if this might have anything to do with your readings once you were dosing Prime daily. Prime will protect the fish from NH3, NO2 and NO3. However, for the nitrite and nitrate they say they know it is true but do not know how it works which they do with ammonia.

However, they suggest dosing every other day not daily dosing. From the Same FAQ section.
How long does Prime® stay bound to the ammonia, nitrite, and nitrates?

A: Prime® will bind up those compounds for up to 48 hours. If they are still present after that time frame, they are released back into the water, unless Prime® is re-dosed accordingly. Also, if your ammonia or nitrite levels are increasing within a 24-hour period, Prime® can be re-dosed every 48 hours.

Because prime detoxifies ammonia by converting it to a form that the bacteria use less efficiently than NH3. This will cause a cycle to take more time but it will not stop it. Dr., Timothy Hovanec, in his instructions for fishless cycling, suggests one not use ammonia detoxifiers during cycling if possible and only use products which are limited to working on chlorine and choramine . I do not know if this slowing also applies to nitrite.

In the end, what matters is if the fish have come through it all OK.


 
So since this thread started no prime doses.

13th April

Ammonia 0.38ppm
Nitrite 26ppb
Nitrate 1.6ppm

15th April

Ammonia 0.29ppm
Nitrite 29ppb
Nitrate 0.8ppm

Nitrite remaining close to zero. Ammonia pretty low and static. Is it even possible that my filter is supporting anaerobic bacteria already? Nitrate seems well and truly under control. I wasnt expecting this.
 

Most reactions

trending

Back
Top