Can there be ammonia and nitrates, but no nitrites? (Free Ammonia?)

[Gideyon]

My tank isn't very old.  I'm on my 3rd week of water testing, and did a partial water change last week. 

The last 2 tests I've seen something peculiar :  ammonia is 0.25, nitrite is 0, and nitrate is about 5ppm.

It read the same last week except nitrate seemed closer to 10ppm.

My understanding of the Nitrogen cycle is that ammonia would be consumed and nitrites are formed.  Nitrites are consumed and nitrates are formed.  So I should normally see ammonia and nitrite at 0, and some value of nitrate (assuming no plants). 

If there's a small amount of ammonia, but no nitrite, is it that there wasn't enough bacteria to consume to ammonia, but plenty to consume to nitrite? 

 

I used API Quick Start before I added the fish. Not sure if that's telling of what's happening.

Or maybe this is normal? 

[AquaAggie]

Are you using the API master test kit or test strips. I have seen some places say that the test kit can some times show a weak positive ammonia. Another possibility is nitrates in your tap water so might test that as well. Something to think about at least

[Gideyon]

API Master Test Kit.  The first week I tested, it was clearly zero, along with nitrites being zero, and nitrates were 5ppm.  So I know it has been 0 before.  But never got lower (or higher) than .25 since.

Just to be on the safe side, I put Prime in until I can do a water change (if necessary).  

 

I will maybe wait until Friday to do another test.  Perhaps it just hasn't been nitrified yet.  

But I'm also learning other things like my baffled output of the filter could decrease aeration of the water which could otherwise help reduce ammonia.  If that's the case, this might be something I have to deal with weekly until it settles.

It's a 10 gallon with about 2inches of gravel substrate.  Only one fish.  

 

[Dirtydave]

Don't drive yourself nuts.Your tank needs some nitrates.20ppm is good for the plants.Keep the ammonia 0 if possible. Just don't overfeed or add more nutrients than your plants can handle.

[Gideyon]

I've also been reading about "Free Ammonia".   The test kits measure Total Ammonia Nitrogen.   I'm not a chemist so I'm not going to pretend to understand it all - but basically this is two types of ammonia measured together.  The one you should be concerned about is the un-ionized or free ammonia.   

I used this calculator: https://thepetsupplyguy.com/unionized-ammonia-calculator/

According to this, and other calculators that do the same thing, my free ammonia is about .003ppm.  You should start to get concerned when it is .02.  So this is okay...

Obviously, 0 is ideal.  

[gardenman]

Can you have ammonia and nitrates but no nitrites? Yes. The reason is that it's a different bacteria that converts nitrites to nitrates. If that bacteria is better established than the bacteria that converts ammonia to nitrites it can be just sitting there waiting for any nitrites to come along and gulping them down and churning out nitrates as quick as they come. Think of it as an assembly line with three stations. The first station has a very slow worker. Every time you look at that first station he/she is methodically plodding away at their task (in this case converting ammonia to nitrites.) The worker at station two however is blindingly fast and every time you look they're just sitting there twiddling their thumbs waiting for the next batch of nitrites from the first station to get to them. As soon as it arrives they've grabbed it converted it to nitrates and passed it on. They've done their job and are sitting there waiting for more. Meanwhile the nitrates are piling up on workstation three. When you look you see all kinds of ammonia, all kinds of nitrates, but no nitrites. The bacteria converting the nitrites to nitrates are just working really hard, fast and doing a good job. It's pretty easy to have ammonia and nitrates without nitrites if those bacteria are thriving.

[MJV Aquatics]

@gardenmanis correct AND also you might also want to test your source water. It is not uncommon these days to have nitrates in your water supply! So if you had nitrates in your source water and BB had not established, you'd have ammonia and nitrates.

[Jsteiner]

It’s just a guess but maybe the different bacteria’s thrive in different temperatures and conditions and the tank is more conducive to the nitrifying bacteria to populate. 

[face]

Ok I’ll start by saying it’s possible to skip the nitrite step especially with bacteria in a bottle products but unlikely there’s a lot of stuff that could be happening for example you could have a small amount of nitrite that is to small for your nitrite test to pick up but your nitrate test still is(nitrate tests can give false positives when nitrite is in the water )or some other false positive there’s a lot of them 

the way I look at it is one way or another you should wait until your ammonia it gone regardless the other thing aren’t important until that happens and imo there’s wonky during a cycle so ya 

as for ammonia vs ammonium it is true that ammonia in low ph is basically harmless but ph is so unpredictable in reality that I wouldn’t worry about the difference there’s a reason most tests test for total ammonia it’s also true that nitrite becomes more toxic in soft water and less in hard 

how are you adding ammonia to your system if your ghosts feeding the amino acids and micro organisms can do stuff to your tests to  personal I’d add a little more ammonia to your system and see what it does 

[MWilk]

I have the opposite problem when cycling new tanks. I have been using seachem stability and see nitrites hang out around 2.0ppm with zero ammonia and minimal nitrate. It just takes some time to settle out. 

[egruttum]

On 9/7/2024 at 5:02 PM, MWilk said:

I have the opposite problem when cycling new tanks. I have been using seachem stability and see nitrites hang out around 2.0ppm with zero ammonia and minimal nitrate. It just takes some time to settle out. 

This is more common.  To continue with @gardenman's excellent example of the assembly line let's pretend the factory has just started production for the first time ever.  The AOB (ammonia oxidizing bacteria) start their work and are beginning to learn their job.  Meanwhile the NOB (nitrite oxidizing bacteria) are sitting around drinking coffee and scratching their balls (anyone remember that joke about the postal service?) waiting for their nitrite to show up.  Now it begins to show up and they start to learn their job.  The AOB had more time to learn their job so the nitrite starts to pile up as the NOB learn their job.  Once both groups get good at their jobs ammonia and nitrite are both zero because as soon as ammonia shows up it gets converted to nitrite and that nitrite quickly gets converted to nitrate.  Now in real life the bacteria aren't learning their job but instead of growing more bacteria.  So potentially a better example is the factory is building additional assembly lines starting with the ammonia to nitrite step.  But I'm not going to rewrite my comment to match that.

[egruttum]

On 9/7/2024 at 11:00 AM, face said:

as for ammonia vs ammonium it is true that ammonia in low ph is basically harmless but ph is so unpredictable in reality that I wouldn’t worry about the difference there’s a reason most tests test for total ammonia it’s also true that nitrite becomes more toxic in soft water and less in hard

Just a clarification here.  When you dissolve ammonia in water it dissolves as NH3 (gas) and NH4+ (aqueous).  We call the NH3 ammonia and the NH4+ ammonium.  They form a stable equilibrium that is controlled mostly by pH but also weakly by temperature and salinity.  As the pH increases the equilibrium shifts towards the gaseous form.  NH3 gas is fairly toxic while NH4+ is fairly non-toxic.  I need to switch computers to get the chart but I believe around a 9.4 pH the concentrations of NH3 and NH4+ are equivalent.  Nitrite is the exact opposite in that it is more toxic at lower pH.  NO2- and HNO2 (nitrous acid) form a stable equilibrium controlled mostly by pH.  Higher pH favors the NO2- ion which is fairly non-toxic.  Lower pH favors nitrous acid which is more toxic.  Water hardness is not really a driver in the equilibrium of NH3/NH4+ or NO2-/HNO2.

I would not call pH unpredictable.  It has very clear drivers for increases/decreases/staying steady.  Most biological processes reduce the pH based on the formation of weak organic acids as metabolic byproducts.  Nitrification is an example of an acid forming process since fully oxidizing 1 gram of ammonia will consume 7.14 grams of alkalinity.  Based on what the aquarium is doing, how hard its being fed, what it's being fed, what water is being changed, etc. controls the pH.  Preventing pH decrease is the main reason that Cory is such a strong believer in crushed coral.  The crushed coral adds alkalinity to the water which acts as a buffer to pH decrease when acids are formed in the water.

Now I am going outside of my zone of expertise with this next comment.  My supposition is that the charged ions are less toxic to life because the charge on them allows the ion to be more easily kept out of the cell, i.e. the cell membrane is more permeable to uncharged molecules as opposed to charged molecules.  I'm going way way way back in my biology trying to remember this and I haven't looked it up yet.  Any cell biologists in here that can confirm or dispel my memory? 

Edited September 9 by egruttum

[egruttum]

On 9/7/2024 at 10:14 AM, Jsteiner said:

It’s just a guess but maybe the different bacteria’s thrive in different temperatures and conditions and the tank is more conducive to the nitrifying bacteria to populate. 

Luckily for life the AOB (ammonia oxidizing bacteria) and NOB (nitrite oxidizing bacteria) thrive in the same conditions.  I say that it's lucky because they need to be in the same conditions to go NH3 --> NO2 --> NO3.  If they did not thrive in the same conditions nitrite would likely build up in many environments and the nitrification cycle would not continue. 

I assume they evolved at the same time and thus they evolved in the same conditions.  But that's just a guess based on my biology knowledge.  I quit biology early in college to focus on chemistry.