# Where ELSE does nitrite come from?



## Linwood (Jun 19, 2014)

I have a pretty large, fully cycled tank. Every once in a while for a couple weeks I get nitrites. It is happening right now, they hang about 0.25ppm, I expect it will go away soon (it has before). 

No ammonia shows in testing. 

It may simply be that I have a spike of over-feeding or similar (could also be a death I do not see), except - it doesn't show ammonia, it doesn't go up very high, it lasts a reasonably long time. 

The tank is 220G and planted, using RODI water (so it's not coming from that). The fertilizers used do not have nitrites, mostly (iron chelate, excel, phosphate, seachem comprehensive, seachem potassium). I do put Osmecote+ in the substrate in gelcaps, but it has been 2-3 months since I added any, so this last spike does not seem likely to be that. It also, interestingly enough, came after a water change.

I did clean the filters pretty heavily - not the Seachem Matrix (there's about 5L worth in the filters), but the media pads had about 50% of them replaced. But remember - no ammonia shows, if I wiped the good bacteria, I would have expected a visible spike there. And besides -- it's a 8 month old tank, I would expect much of the bacteria to be in the substrate and other items inside the tank.

And I would think the plants would absorb a lot on their own. It used to, but in the last couple months the nitrates also are growing (it used to stay near 5ppm, now after 2 weeks it is about 40ppm). A photo below to give a sense of plant density.

My presumption is that I am just over-feeding, it's making ammonia that is quicky absorbed, and the nitrite eating guys just take longer to catch up. But I thought it worth asking whether there is some aspect I may be missing. Some other place for nitrites to originate, interaction of the ferts I may be missing, etc. 

The other smaller tank (45G) gets the same water, has much the same plants, probably more fish per gallon, and shows a steady zero. It also had a similar cleaning of its sole filter at the same time, with no bad effect. 

So... cutting back a bit on food, but wondering if there is anything I may be missing?


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## BruceF (Aug 5, 2011)

"This process is two-step process. The first step of lithoautotrophic nitrification is ammonia oxidation, the conversion of ammonium to nitrite by ammonia-oxidizing bacteria of Nitroso- genera. Then nitrite is oxidized to nitrate by the nitrite-oxidizing bacteria of the Nitro- genera (Sylvia et al., 2005)" 

Step one seems fine but step two is somehow being disturbed. That's my guess.


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## Ghosty (Mar 1, 2015)

The break up of chlorine can cause nitrates due to the compound element of chlorine, or something along those lines, I read that awhile ago someone might correct me,


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## Linwood (Jun 19, 2014)

BruceF said:


> Step one seems fine but step two is somehow being disturbed. That's my guess.


Very possible, but what would one look for, what might cause it? 

The other possibility of course, based on my loose understanding, is that the first step scales up faster (bacteria reproduction is faster), and so a spike in both might show only in the second phase. 

The problem with both of these is the relatively low level of nitrites I see. A scale-up issue I would expect to fall more seriously behind and have a high nitrites rather than a long, spread-out period of low levels. Same with a disturbance in this second phase, like something that selectively killed the nitrite-eating bugs.

Bump:


Ghosty said:


> The break up of chlorine can cause nitrates due to the compound element of chlorine, or something along those lines, I read that awhile ago someone might correct me,


Without commenting on that specifically, there is no chlorine in the tank (I use RODI water, very zero RODI, tested to be zero; the local water is sodium hypochlorite not chloramines so even less likely to be a factor).


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## Ghosty (Mar 1, 2015)

I read awhile something awhile ago about it probably completely wrong hooe you figure it out


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## BruceF (Aug 5, 2011)

Last chemistry class I took was in 1967..... 
http://www.oscarfish.com/article-home/water/71-autotrophic-bacteria-manifesto.html


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## Ghosty (Mar 1, 2015)

Have you maybe changed something food ferts, added something moved something, or maybe forgot to do something in your maintance that your would normally have done, 

Just trying to light up someone's brain with elimination of things

Edited cause I got distracted


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## Coralbandit (Feb 25, 2013)

Most who have completed a fishless cycle will agree(I believe) that the second set of bacteria(that convert nitrite to nitrate) take longer to develop.
That being said I can't believe you could randomly overfeed that much to show(or effect bacteria).
Your tank looks very nice!
I have followed other threads of yours and understand what you mean by "it last a reasonably long time".
Something else is going on IMO.
A false positive would be rejected on next regular test but it could be 2 weeks of this reading possibly?
I am baffled like you ,but I hope I brought up a point or another question.
I test,but not out of control?I keep reef tanks so I'm out of control,but all is subjective?
I'm still after 30 years keeping fish learning to let them tell me if there is an issue.
Hope this helps,and very interesting issue you have going on.Especially 1 tank and not the other?


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## walzon1 (Jan 28, 2014)

I don't see why it's a mystery, you said yourself you heavily cleaned the filters. Ammonia bacteria are extremely fast growing and will rebound extremely quickly. As mentioned nitrite bacteria are slower to recover sometimes taking up to 2-3 weeks to catch up, hence why your showing a small bump in nitrite. Rule is never heavily clean your filters, bacteria heavily colonizes in the part of your filter with the most flow and oxygen, since they are doing most the work the bacterial colonies in your tank will be sparse and small definitely not enough to take up bio-load of your tank. It's like buying a new filter for your tank and only putting half the media from your old filter in the new filter, you wouldn't do that would you. If your were filterless it would be a different story since the filter wouldn;t be taking up most the bio load, then the bacteria would have to colonize elsewhere i.e. more on the powerhead glass plants etc... At least you knew enough not to change your whole filter out.


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## CannaBrain (Oct 3, 2008)

Maybe it's just me, but I don't see an issue here. IMO .25 PPM is hardly a concern/spike. Even if it went up to .5, I don't think you'd have an issue, unless you start to notice signs of stress in your fish/plants, or possibly algae outbreak. 

Anyways, I think it's possible there could be one of many things goin on. Maybe just the bacteria needs to catch up. But It's been shown that nitrites are toxic to terrestrial plants, however I think inconclusive regarding aquatics. Since your tank is cycled, plants will use up some of the ammonia, followed by your nitrosomonas which oxidize the ammonia into nitrites. From the reading I've done, it also seems inconclusive as to whether or not nitrites or nitrates are preferred by plants, but it seems as though they probably are able to use nitrates faster, as nitrites are typically converted faster by your nitrobacter than the time/energy it takes for you plant to convert to usable Nitrogen. 

Your nitrosomonas and nitrobacteria will also have different rates of oxidization based on pH and temperature. 

I guess some things I'm curious about: Are the pH, temp, co2/o2 identical between the two tanks? If they're not, then I think it's safe to say that they may be functioning at different paces between the two tanks. However, I cant imagine it'd make such a big difference, especially if we're talking like less than 2% - 5% differences or so. 

On the other hand, I believe I once read a post on the barrreport forums from tom barr in which he stated


> I have no cycle in any of my tanks.


 (http://www.barrreport.com/forum/bar...lem-during-a-fishless-cycle?p=64051#post64051)
Perhaps, your Ammonia, nitrite, nitrate levels are dictated more by your plants at this point than by bacteria.

I really don't know though, I'm no expert and I hope a guru will be able drop by to shed some light.

EDIT: thought I'd include this link too, some good info. http://www.bioconlabs.com/nitribactfacts.html


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## walzon1 (Jan 28, 2014)

CannaBrain said:


> Maybe it's just me, but I don't see an issue here. IMO .25 PPM is hardly a concern/spike. Even if it went up to .5, I don't think you'd have an issue, unless you start to notice signs of stress in your fish/plants, or possibly algae outbreak.
> 
> Anyways, I think it's possible there could be one of many things goin on. It's been shown that nitrites are toxic to terrestrial plants, however I think inconclusive regarding aquatics. Since your tank is cycled, plants will use up some of the ammonia, followed by your nitrosomonas which oxidize the ammonia into nitrites. From the reading I've done, it also seems inconclusive as to whether or not nitrites or nitrates are preferred by plants, but it seems as though they probably are able to use nitrates faster, as nitrites are typically converted faster by your nitrobacter than the time/energy it takes for you plant to convert to usable Nitrogen.
> 
> ...


 Tome barr plants extremely heavy and stocks fish extremely light, so almost all ammonia is immediately taken up by the plants. This is what he is referring to as no cycle. but most of us don't have 120g fully planted tanks with a small school of tetra and some shrimp either so this doesn't really apply to everyone.


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## CannaBrain (Oct 3, 2008)

walzon1 said:


> Tome barr plants extremely heavy and stocks fish extremely light, so almost all ammonia is immediately taken up by the plants. This is what he is referring to as no cycle. but most of us don't have 120g fully planted tanks with a small school of tetra and some shrimp either so this doesn't really apply to everyone.


Never said it did, however the OP said he's reading 0 ammonia and nitrates. Just trying to offer some possibilities as to why he's only seeing nitrites.


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## Kalyke (Dec 1, 2014)

Is there a particular timeframe for this happening? For example, winter, summer? Do you have RO hooked up to your house water, and has the formulation changed for any of the products or filters you use? 

In conjunction to certain seasons question above? Is their any change in water quality or the water table during seasons due to farm runoff or sewage that maybe your own filters are Ill equipped to handle?


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## Linwood (Jun 19, 2014)

BruceF said:


> Last chemistry class I took was in 1967.....
> http://www.oscarfish.com/article-home/water/71-autotrophic-bacteria-manifesto.html


VERY informative article, digesting now.


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## Linwood (Jun 19, 2014)

Kalyke said:


> Is there a particular timeframe for this happening? For example, winter, summer? Do you have RO hooked up to your house water, and has the formulation changed for any of the products or filters you use?


I do not have that much history. The tank first cycled in Septmber.

Something bad happened to both of my tanks when I was treating for parasites, I am fairly sure involving a polluted water barrel, but the result was they both went into a cycle. The small tank finished normally, the large about the same time EXCEPT that rather than going to zero nitrites, it kept nitrates at a low level for a couple weeks. That was in January.

Now, seemingly out of the blue (but admittedly after a filter clean) it is doing the same - -it has read about .5 to .25 nitrites since 2/24. .

Did the heavy filter clean do it? Certainly possible, but again -- there's about 5 liters of Seachem Matrix in the three canisters that I did not touch. In one filter I changed one pad of 6, in another 3 of 6, and in another 5 of 6. They were getting very ratty (a poor choice of bulk media that does not last long). In no case did I change the first sponge, just rinsed it (in tank water). So there were about 10 pads and 5L of Matrix still in there. Could I hve depleted the bacteria - I guess so, but I do not think so.

As to "what else changed" - the first time it was a water barrel, supposedly food safe, that had something bad in it that caused the tank to produce high levels of ammonia. It took a long time to figure out, so my reaction was to make water faster, and change water faster, trying to stay ahead -- making things worse. When I replaced the barrel, things pretty quickly leveled off and returned to normal, except in the large tank where it had that tail of nitrite. 

Both tanks get the same ferts (proportional to their size). I did change from Seachem iron to DTPA, but in both. They get the same water mix from the RODI, about dKH=4, dGH=6, ph=7.8, both are at 78F. They have similar but not identical plants, the large tank has a lot deeper substrate that is sand rather than gravel+ecco-complete. They both have canister filters, though the large has a bit heavier flow overall, but not hugely so. They both run a low quality UV sanitizer (the kind included on SunSun filters free). 

Since before this started they have both had water changed in roughly the same proportion and roughly the same days. 

The big tanks biggest difference is that it is a sex tank -- almost everything I put in there has some babies. There's a bunch of little molleys, some baby plecos, I got rid of the baby angels. The congos act like they mate but never see any eggs - probably lunch. But I've never read the sex creates nitrites. 

It may be just as simple as I over-cleaned. It just doesn't feel quick right. I would have expected more spike, and less flat low level.


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## Diana (Jan 14, 2010)

Something minor may be happening to the beneficial bacteria. Not enough to kill them, just reduce their efficiency. The ammonia > nitrite bacteria are more tolerant of things, and bounce back faster, so not seeing ammonia is common. The nitrite > nitrate bacteria are more sensitive to whatever happens, and are slower to recover, so there is often a lag in the cycle that shows up as a trace of nitrite. 

What that 'something' is, may already be answered in your post. Disturbing the filter disturbs the bacteria. This can be beneficial, such as cleaning out the debris to assure optimum water flow. The minor disturbance is not enough for our hobby level kits to show a blip in ammonia or nitrite. Actually removing, throwing away, media is bad. You are throwing away bacteria. I have taken as much as 25% of the filter media from a filter and not had a problem, but more than this, and the tank does show a small amount of ammonia or nitrite for a few days until the bacteria can get the population back up. 

Other part of the story:
There are microorganisms that can make the nitrogen cycle run backward. They start with NO3 and produce NO2. This usually happens deep in the substrate, even if it is pretty well aerated.


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## Linwood (Jun 19, 2014)

That article brings up a possibility, where it discusses power outages: 



> The one thing you do not want is to leave the media in your filters, especially in canister filters. In an extended power outage, the oxygen content of the water inside the canisters will expire resulting in the beneficial bacteria shutting down and entering hibernation. In addition, many species of heterotrophic bacteria can continue to function in an absence of oxygen. Since these bacteria can multiply quickly, they can easily over run the autotrophic nitrifying bacteria we are trying to preserve. It is entirely possible, depending on the amount of organics contained within the filters, that these heterotrophic bacteria will cause putrification, which will result in the death of the autotrophic nitrifying bacteria within the canister. If nothing else, remove the media from the canisters and place it into the main tank, where the autotrophic nitrifying bacteria stand a better chance of survival.


When I did the big tank, with three filters, and cleaned them - the filters were without power for about 3 hours +/-, while being cleaned, tank pumped out, pumped back in (it takes a while to exchange 80 gallons). 

So just how long is the above quote talking about before it becomes an issue -- a few hours, or days? I had always heard you had a long time (like day or two) before the good stuff dies.


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## lee739 (Oct 12, 2014)

Have you checked the kit itself? - run parallel samples, RODI and tank water, and make sure the RODI shows as zero.

I always run a control sample when I check for ammonia, as the low levels are hard to pick, and the colour chart offers no help at all....


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## Linwood (Jun 19, 2014)

lee739 said:


> Have you checked the kit itself? - run parallel samples, RODI and tank water, and make sure the RODI shows as zero.
> 
> I always run a control sample when I check for ammonia, as the low levels are hard to pick, and the colour chart offers no help at all....


I have not checked against a control sample but have checked the other tank at the same time in the same way and it consistently reads zero, so while I cannot say the kit is calibrated, it does not appear to be the issue.


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## Diana (Jan 14, 2010)

Well, few more ideas:

Overall, it may be that several different things have happened, close enough in time that the Nitrospira is taking a little time to recover. Any one item is not enough to be a big problem, but, taken together, they have caused enough of a problem and are continuing by slowing the recovery. 

UV: even low efficiency: I have no idea if this is affecting things, but when the nitrifying bacteria reproduce, some do drift in the water. Not many, most just go in living in the biofilm. But they do go colonize other surfaces. I wonder if this UV is just enough (probably combined with some other things) to hinder the recovery? 

Ammonia source in the water: The ammonia from the barrel ought to have helped grow more bacteria, though you would have seen the ammonia and nitrite while it was growing. Doing a bit more of an inadvertent 'fishless' cycle. But with fish in there. 

Cleaning the filter and throwing away some media: I do not know if that is enough to cause this problem by itself. It may be part of the overall picture, but I would think that between the plants and the remaining media there should be enough bio filtration not to show the ammonia or NO2. Aquatic plants do use NO2. 
Allowing the filters to stand: Warmer is worse than cooler. Opening the top can help, even if there is no water movement, though not much. At that temperature I would think you would start seeing some problems in an hour or two. At 3 hours, sealed, no water movement, I think you probably did lose some bacteria. Not a lot, but I think it is also part of the picture. Next time: Dump the media into an open bucket or storage bin of tank water. This has more surface area, so more oxygen, you can stir it occasionally, and you can clean the media in this water. If you do not want to dump the media, and you know the tank will be down for more than 1 hour, then run the filter on a bucket or storage bin, or else add a fountain pump to keep some water moving through the media. A bit of vinyl tubing stuck into the intake ought to be snug enough not to leak much. 

Nitrospira grows best under these conditions, optimum recovery will happen when you keep the tank as close to these conditions as possible:
Warm (upper 70s is great, if the water is well oxygenated)
High O2
Hard water. These bacteria use the carbon in carbonates. Make sure the KH is at least 3 degrees and higher is better. When these bacteria are cultured in the lab or in the factory they are grown in water that is similar to the rift lakes- liquid rock. (KH probably 10-20 degrees) 
High pH. I do not know if the high pH is a specific requirement (I think it is), or it is a side effect of high KH. It is best if the pH is in the upper 7s or low 8s. I know they slow down when the pH is in the 6s, and they seem to do almost nothing when the pH is under 6.5.
Assorted other minerals. I am not sure what all they need, but they are life forms, and probably need pretty much all the minerals that plants and animals need. Regular supplies of plant fertilizer in the water seem to be beneficial. 

If you do not want to run the tank this way (hard, alkaline water) then get a bottle of Dr. Tim's One and Only, or Tetra Safe Start and add this to the tank. These products have Nitrospira, the correct species of bacteria that you need more of in this set up. 
Of course you could grow your own in a bucket, but that will take time. I would add one of these materials now and be done with it.

If you do not want to, or have no access to bacteria in a bottle:

1) Feed less. The protein in fish food is the highest source of nitrogen that is getting turned into ammonia and nitrite. IF the fish will take it low protein food is better. Fresh or lightly cooked vegetables would be a good substitute for fish food for several meals per week. 
2) Make sure the plants' other needs are met, but do not feed any nitrogen fertilizer. Make them go to the ammonia and nitrite as their source of nitrogen. Improve carbon (CO2), lights, other ferts. 
3) Shift the tank as far in the direction of those optimum conditions as you are willing to go.


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## Okedokey (Sep 2, 2014)

Great post Diana


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## Linwood (Jun 19, 2014)

Diana said:


> Overall, it may be that several different things have happened, close enough in time that the Nitrospira is taking a little time to recover.


It almost has to be that, but I remain troubled by the flat plateau instead of a high spike. Frankly, despite it being more of a problem, a higher bell curve type event would make more sense than this low plateau. Being flat implies the recovery rate and nitrite production rate are nearly exactly matched -- "even" does not often occur in nature without some cause.



Diana said:


> UV: even low efficiency: I have no idea if this is affecting things, but when the nitrifying bacteria reproduce, some do drift in the water. Not many, most just go in living in the biofilm. But they do go colonize other surfaces. I wonder if this UV is just enough (probably combined with some other things) to hinder the recovery?


Possibly. On the good side the UV effect is prior to the first sponge filter, i.e. it goes UV -> Sponge -> floss -> Matrix. So repoduction inside the latter three flow out unaffected and into the tank. It's those coming from the tank potentially affected.

I do turn them off when cycling a new tank, e.g. each time I redo my quarantine tank. Haven't here. Maybe I should.




Diana said:


> Ammonia source in the water: The ammonia from the barrel ought to have helped grow more bacteria, though you would have seen the ammonia and nitrite while it was growing. Doing a bit more of an inadvertent 'fishless' cycle. But with fish in there.


Honestly I do not know what was in the barrel. I confirmed the problem by dosing fresh RODI water in the barrel with potassium permanganate, which instantly turned brown (it should stay purple for a day or more in pure water). It was sold as food grade plastic used once for animal feed, was very clean looking, and I cleaned it heavily with chlorine (and yes got all the chlorine out). But the symptom was that the tank continued to produce ammonia when it was used for water changes. Both tanks. I stopped using it when I did the PP test, and the ammonia cleared up quickly afterwards, the nitrites a few days later in the small tank but about 2 weeks in the big.

It could have been leaching organics that reacted both with the PP and was producing ammonia. It could have been something that reacted with PP (metals for example) that was killing the bacteria, making them less effective. I just have no way of knowing -- but it's gone now. Well, except for anything it may have put in the tank (several very heavy water changes were done afterwards trying to reduce that likelihood).




Diana said:


> If you do not want to run the tank this way (hard, alkaline water) ...
> ....
> 
> 
> ...


Actually I like it a bit alkaline (I was a bit north of 7.8 in today's test -- and still at 0.25 nitrites), and while not hard dGH=7 +/- 1 is not exactly soft. This seems to keep the plants and fish happy enough, keeps the ph from swinging around, and the main downside is buying Equilibrium to keep the hardness up.

The rest I try to do, other than feeding. I just never know how much -- but I'm becoming convinced I am feeding too much. It's the continual begging and whining...ok, maybe not whining, but definitely begging. Gets on your nerves after a while, and you throw some more in. Must... stop...


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## Okedokey (Sep 2, 2014)

Please note, if you use Prime, you will see false positive for nitrite and nitrate.


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## Linwood (Jun 19, 2014)

Okedokey said:


> Please note, if you use Prime, you will see false positive for nitrite and nitrate.


As mentioned, using RODI water so no need of prime.


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## Okedokey (Sep 2, 2014)

Linwood said:


> As mentioned, using RODI water so no need of prime.


Sorry I missed that. You RO your own water from chlorinated tap water? This is important as most RO units wont remove chloroamine.


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## Linwood (Jun 19, 2014)

Okedokey said:


> Sorry I missed that. You RO your own water from chlorinated tap water? This is important as most RO units wont remove chloroamine.


Yes, and ours is sodium hypochlorite not chloramine.


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## Okedokey (Sep 2, 2014)

So that is bleach, again it can pass through and indeed damage some RO membranes. It must be removed prior to going in the RO unit, again, using SAFE, or Prime.


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## Diana (Jan 14, 2010)

GH of 7 degrees is fine. 
Is the KH also up a bit? 

Right about nature not doing flat lines very much, but I think it may look like it when using a hobby quality test kit, even if a lab quality test might show it is more variable.


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## Linwood (Jun 19, 2014)

Okedokey said:


> So that is bleach, again it can pass through and indeed damage some RO membranes. It must be removed prior to going in the RO unit, again, using SAFE, or Prime.


No. Sorry, but that's silly, why have an RODI system if it's not set up to remove chlorine, the primary contaminant in tap water. The carbon blocks remove the vast majority of the chlorine, the RO membrane almost all the rest, and the DI media takes out enough I measure zero TDS (yes, I realize it is not zero).

I do not use prime. There's no significant chlorine in the RODI water when it comes out. 



Diana said:


> GH of 7 degrees is fine.
> Is the KH also up a bit?
> 
> Right about nature not doing flat lines very much, but I think it may look like it when using a hobby quality test kit, even if a lab quality test might show it is more variable.


No, though it has been a bit since I tested, the KH in that take actually goes down a bit over time, I've seen it creep down near 2, but it takes about 5-6 weeks (it has been a long time since I went that long without a water change). 

Before all this mess started, that tank had been really stable even if a bit new - it would go 5-6 weeks without a water change, and even then have about 10ppm nitrates; I would do the change mostly because I was feeling guilty. Then camallanus came along, the treatment had me changing water more heavily so I bought that barrel, and it was all downhill from there.


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## Okedokey (Sep 2, 2014)

Linwood said:


> No. Sorry, but that's silly, why have an RODI system if it's not set up to remove chlorine, the primary contaminant in tap water. The carbon blocks remove the vast majority of the chlorine, the RO membrane almost all the rest, and the DI media takes out enough I measure zero TDS (yes, I realize it is not zero).
> 
> I do not use prime. There's no significant chlorine in the RODI water when it comes out.


Thats a circular argument, but to answer it, domestic low pressure RO units are for pathogen and turbidity removal. Anyway, it will pass through and (potentially) damage the membranes; well know effect.

http://msdssearch.dow.com/Published...seps/pdfs/noreg/795-00019.pdf&fromPage=GetDoc (Figure 1)

http://www.google.com.au/url?sa=t&r...M0yzZzKRfSGYBwg&bvm=bv.87519884,d.dGY&cad=rja


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## Linwood (Jun 19, 2014)

Okedokey said:


> Thats a circular argument, but to answer it, domestic low pressure RO units are for pathogen and turbidity removal. Anyway, it will pass through and (potentially) damage the membranes; well know effect.


I'm just plain confused by this. The first reference is about oil contamination in water cleaned up in China and industrial scale units. The second is about effects of sodium hypochlorite, but is on PVDF membranes. I am not very knowledgeable about membrane specifics (but I don't think that is the same as the ones used in aquarium units), but it is also only a few percent on point, since the vast, vast majority of the chlorine is removed by the carbon blocks, not the membrane. A key purpose of the carbon blocks is chlorine removal so it does NOT get to and damage the membrane.

I can't find my particular blocks' removal rate, but in their first few thousand gallons my understanding is that it starts near 100% and remains over 90%. Assuming a tap water content of 1ppm (probably high) with two in series that should put me at 10 ppt going into the membrane at worst. The dow cartridge I use is rated for input at 0.1ppm free chlorine, and whatever is not rejected by it should be removed by the DI cartridge. 

I don't have spec sheets to prove that, I know I've seen them for these carbon blocks, but I cannot find them (I buy Spectrapure blocks) -- however, your comments are the only place I have ever seen indicated that *RODI water from a properly maintained residential system contains sufficient chlorine that one would need to add PRIME to it*.

I cannot argue convincingly otherwise at the moment, but I frankly just do not believe it.

But back to the original topic, since I do NOT add prime, the addition of prime itself is not causing the nitrite readings. I also am not convinced that residual chlorine (especially at those levels) can cause nitrite readings, if for no other reason than it does not in the other tank nor in RODI water tests.

I think this is all off on a tangent to the original question.


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## Okedokey (Sep 2, 2014)

The residual chlorine may be causing bacteria death leading to nitrite, that's my point


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## lee739 (Oct 12, 2014)

I assume you haven't, as I'm sure you would have mentioned it, but have you medicated the tank with anything?


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## Linwood (Jun 19, 2014)

lee739 said:


> I assume you haven't, as I'm sure you would have mentioned it, but have you medicated the tank with anything?


Not in recent times, last was levamisole back in early december. 

By the way -- it went to zero this morning, so a bit over a week.


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## lee739 (Oct 12, 2014)

Boom! do some googling about levamisole and nitrite - I participated in a thread on a local forum here whereby someone caused a major (5ppm++) nitrite spike dosing levamisole. There are other reports online of similar too.


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## Linwood (Jun 19, 2014)

lee739 said:


> Boom! do some googling about levamisole and nitrite - I participated in a thread on a local forum here whereby someone caused a major (5ppm++) nitrite spike dosing levamisole. There are other reports online of similar too.


That was December (I was mistaken - late december). I went completely back to zero for at least a month before seeing nitrites again.


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## lee739 (Oct 12, 2014)

This could be a stretch - maybe residual levamisole is weakening/suppressing the nitrite formers, so any nitrogen stress in the system is overloading them to a small degree? The other cases I've read about seem to not show ammonia spikes, just nitrite. Are you sure a fish didn't die unaccounted? Any other cause for increased nitrogen wastes?


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## Coralbandit (Feb 25, 2013)

A;
you have been to zero and come back to problem since the use of the Levamisole HCI.
B;
with all due respect lee I would like to hear what Charles(inkmaker ;the supplier/manufacturer of levamisole) has to say?
I can touch base with him on this if no one else wants to?
IMO since it needs to be dosed 2x to work(only 3 weeks apart) I don't think this has much merit(not many meds last like CU2) over long term(months).


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## Linwood (Jun 19, 2014)

lee739 said:


> This could be a stretch - maybe residual levamisole is weakening/suppressing the nitrite formers, so any nitrogen stress in the system is overloading them to a small degree? The other cases I've read about seem to not show ammonia spikes, just nitrite. Are you sure a fish didn't die unaccounted? Any other cause for increased nitrogen wastes?


No, I am not -- it's a big tank with lots of hiding spaces. As mentioned above, this could all be from very mundane causes and/or some mistake I made. I just do not SEE any such.



Coralbandit said:


> A;
> you have been to zero and come back to problem since the use of the Levamisole HCI.
> B;
> with all due respect lee I would like to hear what Charles(inkmaker ;the supplier/manufacturer of levamisole) has to say?
> ...


I have been in touch generally with him (that is where i got my dose and whose instructions I folloed), and he says that at the recommended doses (which I used) it does not harm the nitrifying bacteria. His related recommendation is not to "clean" that tank so as to kill such. But feel free to ask.

Also, there were 5 water changes (including the one to remove it) since the last treatment (I looked, that was 1/11), the first three were 125G, the next two 85G (while it is a 220G tank I suspect it has only about 180G of water +/- due to rocks, stump, substrate, etc.). So at the start of this spike, there is no reason to think a new "event" was precipitated by the levamisole from that long ago. 

I think it is much more likely I am either over feeding or had something die. But I remain a bit puzzled by the lack of ammonia, and lack of "spike". However, the relatively slow growth rate of the nitrite eaters, and my filter clean, makes for at least as plausible an event. I also did not know (but have learned, thank you) that plants do not willingly take up nitrites.


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## Okedokey (Sep 2, 2014)

Ensure you have oxygenation at night, low oxygen will prevent conversion from nitrite to nitrate.


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## Linwood (Jun 19, 2014)

Okedokey said:


> Ensure you have oxygenation at night, low oxygen will prevent conversion from nitrite to nitrate.


Good there, have three spray bars going (here's a view from underneath).










(That's from the tanks first days so few plants shown).


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