Nitrogen assimilation (anabolism) by bacteria

[Dan_P]

The aquarium is stable at 5mg/l,

How is the nitrate being measured?

 

[sixty_reefer]

How is the nitrate being measured?

With a nitrate test kit. As a note I’m not adding nitrate to the tank, I’m adding early forms of nitrogen

This is how the protein skimmer looks like, taking in account that there is no fish it seems to be working well.

 

[Dan_P]

It can, if it’s collecting bacteria that uses nitrogen to create body mass.

How old was the skimmate in which you measured 100 ppm nitrate?

Have you confirmed that organisms in the aquarium water can convert ammonia to nitrate by adding ammonia to a sample of aquarium water and measuring nitrite concentration over time? The length of time should be equal to the age of the skimmate you tested for nitrate.

 

[Dan_P]

With a nitrate test kit.

What test kit are you using?

 

[sixty_reefer]

How old was the skimmate in which you measured 100 ppm nitrate?

Since the beginning of the experiment although on Sunday I’ve started taking a few ml and spot feed a feather star. In hope that this method is producing enough microbes to feed one.

Have you confirmed that organisms in the aquarium water can convert ammonia to nitrate by adding ammonia to a sample of aquarium water and measuring nitrite concentration over time? The length of time should be equal to the age of the skimmate you tested for nitrate.

Yes, that was the first thing I did, as I set up the aquarium with cycled media and water, I’ve used Dr. Tim’s ammonium chloride to ensure normal nitrogen cycle was working.

 

[sixty_reefer]

What test kit are you using?

JBL PROAQUATEST LAB Marin

Simple monitoring of the water values in marine aquariums. pH, KH, Ca, Mg, Cu, NH4, NO2, NO3, PO4, SiO2, O2

www.jbl.de

I only use JBL, they the most precise in the hobby after Hanna imo. Ive compared them agains ICP and agains Salifer and API.

 

[Dan_P]

Since the beginning of the experiment although on Sunday I’ve started taking a few ml and spot feed a feather star. In hope that this method is producing enough microbes to feed one.

That is pretty old skimmate, and likely if it has not been stored in the freezer, no longer represents what is in the aquarium water.

Yes, that was the first thing I did, as I set up the aquarium with cycled media and water, I’ve used Dr. Tim’s ammonium chloride to ensure normal nitrogen cycle was working.

I was more interested in the aquarium water itself because it is unlikely to process ammonia.

Ok, we will have to assume the skimmate is carbon deficient which rotted, producing ammonia. We will also assume that there has been enough time to grow a sufficiently large population of nitrifying bacteria to generate 100 ppm of nitrate. This means that no conclusion can be drawn from the fact that 100 ppm nitrate was observed in the skimmer. Right?

 

[sixty_reefer]

That is pretty old skimmate, and likely if it has not been stored in the freezer, no longer represents what is in the aquarium water.

It’s around 10 to 12 days old, the production of foam only started after the organic carbon was introduced.

I was more interested in the aquarium water itself because it is unlikely to process ammonia.

Ok, we will have to assume the skimmate is carbon deficient which rotted, producing ammonia. We will also assume that there has been enough time to grow a sufficiently large population of nitrifying bacteria to generate 100 ppm of nitrate. This means that no conclusion can be drawn from the fact that 100 ppm nitrate was observed in the skimmer. Right?

I’m not sure if I understand the above.

 

[Dan_P]

JBL PROAQUATEST LAB Marin

Simple monitoring of the water values in marine aquariums. pH, KH, Ca, Mg, Cu, NH4, NO2, NO3, PO4, SiO2, O2

www.jbl.de

I only use JBL, they the most precise in the hobby after Hanna imo. Ive compared them agains ICP and agains Salifer and API.

OK thanks. I needed a rough idea about the precision of the numbers you are reporting. I will be attaching a +/- 50% when I think about the test results.

 

[Dan_P]

I’m not sure if I understand the above.

No prob. Let me expand on this.

Since a skimmer cannot concentrate nitrate, the large concentration you measured has to come from somewhere else. I assume the likely source is from the oxidation of ammonia by bacteria. The ammonia comes from bacterial action on organic nitrogen in the skimmate. When the C:N ratio of this organic matter is too low for complete consumption of the nitrogen by the bacteria, the bacteria excretes the unneeded ammonia. Ammonia is typically not rapidly convert to nitrate in aquarium water, but enough time, the few nitrifying bacteria in aquarium water collected by the skimmate will grow to a sufficiently large number to convert the ammonia to the observed 100 ppm nitrate.

 

[sixty_reefer]

No prob. Let me expand on this.

Since a skimmer cannot concentrate nitrate, the large concentration you measured has to come from somewhere else. I assume the likely source is from the oxidation of ammonia by bacteria. The ammonia comes from bacterial action on organic nitrogen in the skimmate. When the C:N ratio of this organic matter is too low for complete consumption of the nitrogen by the bacteria, the bacteria excretes the unneeded ammonia. Ammonia is typically not rapidly convert to nitrate in aquarium water, but enough time, the few nitrifying bacteria in aquarium water collected by the skimmate will grow to a sufficiently large number to convert the ammonia to the observed 100 ppm nitrate.

It’s plausible to happen, I wouldn’t be able to confirm it as it would be out of my scope of abilities.

 

[sixty_reefer]

No prob. Let me expand on this.

Since a skimmer cannot concentrate nitrate, the large concentration you measured has to come from somewhere else. I assume the likely source is from the oxidation of ammonia by bacteria. The ammonia comes from bacterial action on organic nitrogen in the skimmate. When the C:N ratio of this organic matter is too low for complete consumption of the nitrogen by the bacteria, the bacteria excretes the unneeded ammonia. Ammonia is typically not rapidly convert to nitrate in aquarium water, but enough time, the few nitrifying bacteria in aquarium water collected by the skimmate will grow to a sufficiently large number to convert the ammonia to the observed 100 ppm nitrate.

There is also a second hypothesis, a few years back I’ve noticed that my test kits do react to organics. In that experiment I was removing sand from my tank, collecting the excess organic trapped in the sand and diluting them into 0ppm water, I noticed in those tests that my test kits react to organic in the water and it would show nitrates value in line with the amount of organic added to the test solution.

This means as I diluted 1ml of my protein skimmer contents with 9 ml of 0 ppm new water that the result could just be a indicator of a large concentration of organic material in the collection cup and not actually nitrate.


I believe that for clarity this needs to be mentioned.

 

[Dan_P]

There is also a second hypothesis, a few years back I’ve noticed that my test kits do react to organics. In that experiment I was removing sand from my tank, collecting the excess organic trapped in the sand and diluting them into 0ppm water, I noticed in those tests that my test kits react to organic in the water and it would show nitrates value in line with the amount of organic added to the test solution.

This means as I diluted 1ml of my protein skimmer contents with 9 ml of 0 ppm new water that the result could just be a indicator of a large concentration of organic material in the collection cup and not actually nitrate.


I believe that for clarity this needs to be mentioned.

i doubt the chemistry in a nitrate test kit would react with organic matter in any meaningful way. What you observed was probably a case of the sample being contaminated with nitrite or nitrate.

 

[sixty_reefer]

i doubt the chemistry in a nitrate test kit would react with organic matter in any meaningful way. What you observed was probably a case of the sample being contaminated with nitrite or nitrate.

It was a weird reaction, not to sure what happened, as with this one, we can only have indications on what could possibly be happening, its one of them that we will probably never really know what’s doing what. In the meantime I’ll carry on with it, see where it takes me.

Nitrates here’s my conclusion:
Both vessels are in RO, vessel on the right is control to illustrate that there is no nitrates presence, vessel on the left is the same with a large piece of macro algae. 5ppm of nitrates extracted from a piece of macro algae under 10 minutes. I don’t mind doing a full 10 minute video on the phosphates or nitrates test.