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Old 01-03-2014, 05:35 AM   #221
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Source: SimplyDiscus.com: Microscopes: Nitrite Toxicity in the Aquarium by Ardan Huck
"Salt added to the aquarium, usually 2 tablespoons per 10 gallons water, helps the fish because the chloride ion (cl-) from the NACL (sodium chloride, or salt) attaches to the gill cells where oxygen enters the blood. This is also the place where nitrite enters the blood, therefore the chloride blocks the nitrite from entering. This only works well if the pH is above 7.0 as in acidic conditions Nitrite (NO2) will bind with hydrogen ions, H+ (acid contains more H+) and form Nitrous acid (HNO2). Nitrous acid is not blocked by CL- ions at the gill site, and thus can pass freely into the blood. "
Salt added for fish-in helps fish live when you get to nitrites phase?

"Water changes are often used to reduce the nitrite levels in the aquarium, however, changing 90% of the water will only reduce the nitrite concentration by 30% (Kohler, 1997). "
WHAT???? I have GOT to find this study this cites!!!!!!
Edit: It was not a study but a magazine article, so I can't put enough weight on it. Also, I can't find anywhere to read the article
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Old 01-03-2014, 07:03 AM   #222
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Quote:
Originally Posted by threnjen View Post
Source: SimplyDiscus.com: Microscopes: Nitrite Toxicity in the Aquarium by Ardan Huck
"Salt added to the aquarium, usually 2 tablespoons per 10 gallons water, helps the fish because the chloride ion (cl-) from the NACL (sodium chloride, or salt) attaches to the gill cells where oxygen enters the blood. This is also the place where nitrite enters the blood, therefore the chloride blocks the nitrite from entering. This only works well if the pH is above 7.0 as in acidic conditions Nitrite (NO2) will bind with hydrogen ions, H+ (acid contains more H+) and form Nitrous acid (HNO2). Nitrous acid is not blocked by CL- ions at the gill site, and thus can pass freely into the blood. "
Salt added for fish-in helps fish live when you get to nitrites phase?

"Water changes are often used to reduce the nitrite levels in the aquarium, however, changing 90% of the water will only reduce the nitrite concentration by 30% (Kohler, 1997). "
WHAT???? I have GOT to find this study this cites!!!!!!
Edit: It was not a study but a magazine article, so I can't put enough weight on it. Also, I can't find anywhere to read the article

I had read much of this about the chloride. I didn't report because our experiment and research was dedicated to fishless cycling and not exposure to fish. I have probably lead us down this route so apologies but if you are happy to go with both studies then so am I. I thought it was commonly thought that nitrite was less toxic than ammonia and it attacks the fish in a different wau although both lead to gasping. Nitrite alters the blood cells if the fish removing the oxygen. I believe

I am starting to lose track if where we are up to now. I think it would be a good idea to compile test parameters for the helpers with what we know so far as wel as compile some facts on what we have learned so far maybe on to a word document. What do you think?
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Old 01-03-2014, 07:36 AM   #223
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I'm not even going to try to read all these articles but I like the stockpile that you are creating. It might be worth making a new thread of a database of all of these scientific papers and see if it can get stickied.
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Old 01-03-2014, 08:22 AM   #224
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I'm not even going to try to read all these articles but I like the stockpile that you are creating. It might be worth making a new thread of a database of all of these scientific papers and see if it can get stickied.

The thing is, most of the stuff we have learned is not new knowledge. However, we have learned some things that may not have been tested during a fishless cycle.

Some interesting facts that we have uncovered (not new) is that ammonia readings of say 0.25ppm are less toxic than originally thought. This is why I suggested in the other thread that water need not be changed if ammonia stays at this level. At that pH. As you may know. Actual free ammonia toxicity increases with pH. It baffles me that the OP has even gone as far as to add prime at free ammonia toxicity levels way below the threshold harmless to fish. It appears that some advisors who understand this feel it is necessary to advocate water changes to the newbie as a precautionary measure. Whilst this is a sensible approach I feel that people have the right to expand their knowledge further if they wish and a stickies maybe the way to do this. Although I believe there are adequate materials posted on this forum already covering this particular topic. We need to do more work and research our next step is to figure out just how toxic nitrites are to fish, what levels of exposure are harmful and how much nitrite is produced from a unit of ammonia. How efficient are nitrite consuming bacteria at consuming nitrite and is it easily taken care of in low doses before it can harm fish.

This post is not aimed at anyone in particular and we are still trying to do more research. Any help is appreciated
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Old 01-03-2014, 12:54 PM   #225
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Interesting paper
http://repositorio-aberto.up.pt/bits...76/2/13766.pdf

Again confirms that nitrospira thrive at lower nitrite concentrations whilst nitrobacter thrive at higher concentrations. According to this. Nitrospira did not come back when concentrations were lowered but may have been due to nitrospira's slow reproduction time and test length. It was said that the bacteria coexisted. This could mean that higher ammonia dosing and subsequent high nitrites may complete a cycle faster as nitrobacter is in fact a quicker multiplayer. Having said that are the low concentrations we use when cycling enough to spawn nitrobacter? I would say not as other studies have shown nitrospira to be the dominant strain during experiments that use considerably higher amounts of nitrite.

Even if the higher end of nitrite we get in our aquariums was enough to spawn nitrobacter this would be a gradual thing as these tests were conducted with an immediate initiation of nitrite which would not be true during a cycle as nitrite production would be reliant on ammonia consumption. This would mean nitrite would start small spawning nitrospira then the nitrobacter would start to grow and become the dominant strain suppressing nitrospira. This would results in an inefficient use of surface area and inefficient consummation of nitrite. In my opinion based on the info.

This is if course hypothetical since I believe from what I have read that the concentrations of nitrite would not be enough to encourage nitrobacter growth.

Nitrospira is a recent discovery and has yet to be sufficiently studied in order to understand its efficiency.

In relation to nitrite toxicity, I haven't found anything that suggests what levels of nitrite are lethal to fish. I read 1ppm is bad but not backed up by scientific data.

So that means if 1ppm ammonia converts to 2.7ppm nitrite an ammonia concentration of 1ppm would require a water change to dilute the nitrites or maybe this chloride buffer? Best to dilute in my opinion depending on tapwater baseline. However if ammonia was 0.25ppm that would mean we would only have 0.6ppm nitrite which is less than one (assuming 1ppm is in actual fact toxic to fish) 0.6ppm is fairly close to 1ppm which leads me to my next question.
How accurate are our test kits? Does it just turn the colour it is closest to? Could 0.25ppm actually be 0.1 ppm which would mean 0.2 ppm of nitrite. See what I'm saying?

We need to understand how toxic nitrite is to fish and at what levels? There must be a study on this?
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Old 01-03-2014, 05:12 PM   #226
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LOL Caliban! In one post you're trying to keep us on track, in the next one you're off on the irresistible tangent

This is all so interesting, it's hard to keep on track!

I agree with your post a few back - we need to come up with the test parameters for the volunteers. My husband advised me that first I need to make a chart of all of the "known" parameters relating to bacteria growth, using all of our sources. i.e. temperature (not just the ideal temps - how slowed is growth outside of them?), rate of doubling of colonies, proportion of colonies in fully cycled samples (I HAVE seen bits of this, somewhere, about the proportions) etc, ideal DO, etc. Then from there we form our hypotheses. He said that I have seen enough data that I should be able to easily run a simulation of what I would expect to see given different dosing scenarios. I will try to work on this today and post them.

As far as hypotheses, I *think*, and I can only say I think as I need to think it through more, that ultimately *my* hypothesis (I believe yours will be different) will be that:
a) The level of dosing does not influence the cycle length, but does influence the end nitrification capacity
b) Water changes can be eliminated through manual additions of phosphorus (fish food) and baking soda at cycle start
c) Cycles without water changes will complete faster than cycles with water changes
d) I feel uncertain on this one. But I'll say it. After initial dose is reached, no additional ammonia is required, and will only prolong the cycle.
e) No levels of ammonia or nitrite in our scale of application will stall the cycle

To address these in turn:
a) I'm not on board anymore that EITHER your .25 dose will end faster OR that my madcap 18ppm dose will end faster. I think it all ends up the same because I've seen so many lab graphs charting the cycle. To that end I think it will take exactly the same-ish amount of time to complete the cycle for these dosings and therefore a larger dose will prove to be more efficient
b) We only water change to stabilize pH and phosphorus, but these readily available additives make that irrelevant, and affect c
c) I think that the cycle is slowed by water changes because you are removing substrate that the nitrite oxidizing bacteria need to eat and multiply. If all is left alone, I propose the ammonia eating bacteria will produce exactly the correct amount of nitrite that the nitrite eating bacteria must consume in order to create a perfectly balanced population.
d) Why do we dose back up? Is it because we fear the ammonia eating bacteria die? Or is it because we want to be sure that the bacteria can successfully eat Xppm all at once (rather than the same individual bacteria eating some every day). If it's the latter, then a higher initial dose will do the job. aka Dose it to 8ppm and never add ammonia again. If it's the former - they don't. We have proven this.
e) I simply believe this to be true after all of our work
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Old 01-03-2014, 05:13 PM   #227
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Originally Posted by Caliban07 View Post
We need to understand how toxic nitrite is to fish and at what levels? There must be a study on this?
There are lots! One of the papers I read on nitrite toxicity in fish mentions that there are over 40 papers about it. So the truth is out there.
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Old 01-03-2014, 05:23 PM   #228
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I just found a blatant error in one of our good sources. This is why only the base scientific paper is the best source.

Nitrifying Bacteria Facts
We like this paper right? I've looked at it a lot.

But it says:
"Nitrosomonas growth is inhibited at a pH of 6.5. All nitrification is inhibited if the pH drops to 6.0 or less. Care must be taken to monitor ammonia if the pH begins to drop close to 6.5. At this pH almost all of the ammonia present in the water will be in the mildly toxic, ionized NH3+ state."

Um.... no? Doesn't a low pH present the lowest amount of Free Ammonia NH3?
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Old 01-03-2014, 06:05 PM   #229
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Source: BMC Microbiology | Full text | Strategies of Nitrosomonas europaea 19718 to counter low dissolved oxygen and high nitrite concentrations 2010

"Cell growth [of Nitrosomonas] was not detected at an initial NO2- concentration of 560 mg-N/L and DO = 1.5 mg O2/L, even after 2 weeks of incubation (data not shown). An initial NO2- concentration of 280 mg NO2--N/L and DO = 1.5 mg O2/L, resulted in a lag phase one day longer than that in the initial absence of nitrite (Figure 4 D1-D2 and Figure 2, B1-B2, respectively). However, the overall cell yield was not impacted. The extent of NH3 oxidized to NO2- in the presence of 280 mg NO2--N/L (88 ± 5%, n = 2) was not significantly different (α = 0.05) than in the absence of nitrite (90 ± 10%, n = 2). "

Even at 280ppm, Nitrosomonas still grew, it just had slower startup.
Nitrosomonas is NOT AFFECTED by Nitrite on the scale that we use in our aquariums
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Old 01-03-2014, 06:28 PM   #230
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Source: JSTOR: An Error Occurred Setting Your User Cookie

Nitrobacter (not spira, possibly irrelevant) were shown to grown in culture with a doubling time of .6 days

Source: Nitrospira-Like Bacteria Associated with Nitrite Oxidation in Freshwater Aquaria
"Whether in pure culture or on biofilters, NOB are slowly growing organisms with doubling times from 12 to 32 h (3, 5, 7). Therefore, in newly set up aquaria, ammonia and nitrite can reach concentrations toxic to fish before a sufficient biomass of AOB and NOB becomes established"

Trying to find doubling times so I can chart it...
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