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Old 12-29-2013, 03:31 AM   #131
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A claim from a non-chemist:
"PPM is an expression of mg/L, so in other words, it is a relationship by weight. 1 PPM of ammonia means that each liter contains 1 mg of ammonia. With a molar mass of 17.031 g/mol (1 mol = 6.022 * 10^23 ) that means that that mg of ammonia contains (6.022 * 10^23 / 17.031) / 1000 = 3.536 * 10^19 molecules of ammonia. When those molecules of ammonia get the three hydrogen atoms replaced by two oxygen atoms to become a nitrite ion, all of a sudden we have 46.0055 / 17.031 = 2.7 times the original weight (1 mg) of nitrite in that liter of water, so now we have 2.7 PPM of nitrite. Same number of molecules, but each one weighs more. When those nitrite ions get an extra oxygen atom added to turn them into nitrate, we now have 62.0049 / 46.0055 = 1.35 times more weight yet again, for a total of 3.64 PPM of nitrate."
Source: 1 ppm ammonia = 1 ppm nitrite = 1 ppm nitrate?

If this person's napkin math is correct, 1ppm ammonia converts to 2.7ppm nitrIte.

I can use this to make my own napkin math to estimate the TAN (total ammonia NH3 + NH4) in my system, and then figure out my bad ammonia (NH3).
The day I had .5 nitrites, my TAN went from 18 to 17.81
Next day I had 3ish nitrites, so we'll say I dropped 1ppm ammonia, to 16.81
Next day 5 nitrites, so we'll say I dropped another 1ppm, 15.81
Next day, well, nitrites are capped out. But surely the bacteria is doubled, so let's say I lost 2ppm ammonia, plus a little extra. Let's call it 13.5

We'll say based on the NH3 to NH4 math that the free ammonia (Nh3) in my system is .37125

This should be toxic to my second-level bacteria. But, my nitrite eating bacteria ARE reproducing. I know this because I HAVE nitrates.
So what gives? This is the next part of the research.
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Old 12-29-2013, 03:56 AM   #132
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I wish I could access the entire paper I want to cite, but the abstract may be enough.

Nitrite-eating bacteria, primarily Nitrospira, are NOT affected or inhibited until 10ppm of free ammonia (NH3). Now as we have learned, we don't get levels of NH3 that are this high in aquaria because most of our ammonia reading is actually ammonium.

2006 scientific paper. Source

"Batch tests were carried out with Nitrospira in mixed and pure cultures using concentrations of free ammonia widely believed to be inhibitory to nitrite-oxidizing organisms. The mixed culture batch tests were conducted with mixed liquor from a bench scale completely stirred tank reactor (CSTR) treating a synthetic wastewater having a low C:N ratio. Nitrospira were confirmed as the dominant nitrite oxidizers via RNA slot blotting. Nitrospira moscoviensis were used for the pure culture trials. The results from this study suggest that free ammonia (NH3-N) concentrations of up to 10 mg/L were not inhibitory to Nitrospira either in situ or in pure culture."

Nitrobacter, on the other hand, IS inhibited by free ammonia NH3, starting at levels somewhere from .1-1.0
Source: http://ftp.mpi-bremen.de/pub/molecol...ication_detail Page 9, section "Inhibition by Free Ammonia"

So far, we have confirmed that ammonia levels that we actually see in our cycle process will not inhibit either first phase or second phase bacterial production.

Now to tackle: How/why does the cycle stall out due to high Nitrites? This will be the focus of my next research.
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Old 12-29-2013, 06:08 AM   #133
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Ok first of all, I was having a nice dream then woke up to this so thanks for that. I am going to read all articles now however, first thing that springs to mind to me from what I have read is that if our test kits are measuring sum ammonia, this would mean that a reading of 0.25ppm ammonia during a fish in cycle is actually much less! since my pH is 7.6 Which makes fish in cycling a bit more appealing we also know that when adding ammo lock we turn the ammonia in to ammonium. You could have a look at how ammo lock does this. Our test kits still read high ammonia even after ammo lock is added.

Now you could also fishless cycle 2 ways. You could lower the ph and dose more ammonia since only a small percentage would be free or you could increase ph and dose less ammonia to get a higher percentage of free ammonia.

My question is this. I have read that nitrosomonas still convert ammonium but nitrospira do carry on this may be due to ph since I believe thst below a certain ph value ammonia becomes ammonium.

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Old 12-29-2013, 06:12 AM   #134
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Both the free ammonia (NH3) and ammonium (NH4) seem to be converted to nitrite, it is just the question of how much of it is toxic (the NH3) to both the nitrosomonas and nitrospira. The nitrospira is just converting nitrite so it doesn't care about the ammonium as a food source.
I *think*, not 100% certain on that claim, cannot recall.

Overall I think it's best to cycle with the lowest pH reasonable in order to keep the free ammonia low, because the nitrosomonas can convert it either way, and this may allow more Nitrobacter to grow (in addition to Nitrospira)

I decided not to work on the nitrite oxidizing bacteria today because I just don't have any more brain bandwidth lol
It's 2:20 AM here, off to sleep.
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Old 12-29-2013, 06:25 AM   #135
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http://www.ncbi.nlm.nih.gov/m/pubmed...872501/related

Ok this article claims that nitrosomonas bacteria does not die off when subjected to low ammonium. It is outcompeted but goes dormant and recovers10 weeks after the last dose of ammonium and continues to convert the ammonia 48 hrs after new dosing

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Old 12-29-2013, 05:22 PM   #136
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Quote:
Originally Posted by Caliban07 View Post
Growth at low ammonium concentrations a - PubMed Mobile

Ok this article claims that nitrosomonas bacteria does not die off when subjected to low ammonium. It is outcompeted but goes dormant and recovers10 weeks after the last dose of ammonium and continues to convert the ammonia 48 hrs after new dosing

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That is really interesting. Where are you going with this?

Challenging the assumption that our bacteria die off if we make "too much" with the cycle? I've always heard that the excess will die off but apparently it just goes dormant for weeks at a time?
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Old 12-29-2013, 05:41 PM   #137
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That's according to this article yes. I've always questioned the the fact the bacteria die off without food. Without oxygen yes if course but bacteria have survived millions of years if be a bit disappointed if it gave up since it number 1 aim is survival.
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Old 12-29-2013, 05:54 PM   #138
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There are also claims that high levels of nitrite does inhibit ammonia nitrifying bacteria although not massively and there is a suggestion that ammonia dosing should be low in order to let the nitrospira catch up as not to allow nitrites to build up.

What I am interested to know is. At 4ppm ammonia according to api test kit. How much of that is free ammonia? We read that it depends on ph levels but if at my ph of 7.5. The articles claim I would have 0.5% free ammonia which works out at 0.02ppm

This doesn't make sense though as I'm sure dark green ammonia 4ppm on API has killed people's fish before now. Unless of course these were people with a high ph increasing the percentage of free ammonia? Does this sound right?

I read a hell if a lot this morning I need help lol.
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Old 12-29-2013, 06:05 PM   #139
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Ahh we got moved

That's a good question re: the free ammonia levels. I follow your statements

I think the link that Mebbid posted is actually more accurate than that quote I posted [regarding free ammonia levels in our total ammonia reading] because free ammonia level is related to BOTH temp and pH. I think that article I quoted from wasn't quite as accurate since it was not taking temperature into account.
So in your example at pH 7.5 assuming a standard-ish temp of 26C then 4.0ppm TAN has free ammonia in the toxic range, at .075ish
According to the charts in the link.
I can't edit out that quote I posted or I would, as I think the charts in the link are more accurate.
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Old 12-29-2013, 06:10 PM   #140
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On another practical application note re: my bucket cycle, the cycle is coming along really fast. TAN(ammonia+ammonium) dropped into readable levels and I have tons of nitrates. Based on the nitrates I think I'm down to 5ppm TAN from my estimated high of 18ppm.
I saw the pH was starting to crash, it was down to about 6.5. So I added a dab of baking soda, although I haven't tested again yet because I wanted it to circulate.
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