Interview With Dr. Timothy A. Hovanec

[rabbut]

Not necessarily. In a cycled tank the level of ammonia (and from this nitrite) production is equal to the amount which can be processed by the bacteria. There will always be some levels of ammonia and nitrite, just below that which we can test. The amount of ammonia produced will be in constant flux so there will be peaks and troughs in the levels (albeit very small) of ammonia and nitrite in a tank. I would expect a small ammonia spike after feeding, for example.

Obviously the above should not lead to levels in the 2ppm range.

Poorly frased on my part, sorry. I should have put, ammonia and nitrite should always be undetectable in a cycled tank, rather than zero. I forgot we are talking about things in a scientific context here, and thus zero to 2d.p. on a hobby test kit cannot be considered accurate I do somethimes test after feeding and never see spikes on my kits that are readable, so IMO and experience, our test kits should always say zero in a cycled tank, even if ammonia and nitrite aren't zero.

This is something that supports the advise given by regular forum members, in that liquid kits are better than strips or tablets. Interestingly Dr Hovanec does not rate tablets over strips, as is the consencus amongst members on here... Dr Hovanec recomends a different brand to API which is a brand swarn by by most on here, instenad recomending Aquarium systems or Kordon kits. I wonder if this is a recomendation to use kits by his company, or genuine recomendations that he is making from his experience

I put it down to him knowing his stuff. I have found the API tests to be mostly useless and agree with them giving false positive results (such as RO water mixed with salt giving levels of ammonia and nitrates off the charts). Also, someone mentioned a while ago about moaning to their water company cos their tap levels were too high and his accurate and properly calibrated test measured 27ppm in a tank which API was measuring up in the 80s.

Of course, one could always PM him and find out

I know you have seen API tests to be inaccurate, andy, but that does not seem to be consistant with other members experieces. I cannot comment here, as I don't use API and thus don't know their accuracy. Also, I haven't used either brand montioned by Dr Hovanec, so I can't comment on them either.

We recomend measuring nitrite concerntation to newbies, so this supports us here, though we tend to give ammonia more thought than nitrite, as ammonia is more toxic and does lasting damage, unlike (as far as I'm aware) nitrite.

I think you may be wrong here. Nitrite binds to Haemoglobins and prevents the fish from being able to transport blood to where it is needed. I recall Neale Monks once described the choice between whether nitrites or ammonia is worst as chosing between being killed by stabbing or gunshot; both bad and undesirable.

I think again that I could have frased this better. As far as I'm aware ammonia does lasting damage to the gills, where as nitrite does no lasting damage, exhibiting the short-term effects you describe above? Granted, they both can kill at low levels, but to me a substance that does lasting damage in the same concerntrations as another substance that only has short-term effects due to the exposure, then I would prefur to be exposed to the substance with the short-term effects. Obviously, past a point, both will kill outright in accute exposure cases.

All the best
Rabbut

 

[rabbut]

If anyone whom may be reading this thread is wondering why we are contradicting "common knowlage" in the hobby by stating that Bactinettes with Nitrobacter as the primary nitrite oxidising bacteria is not using the correct bacteria and that Nitrospira type bacteria is what the porduct theoretically needs to work fully. To clarify to them, where this is comming from, and also to try and help Axle with his advanced reading on the topic, if you haven't already, I'd advise reading through the research paper Dr Hovanec wrote on the subject here This is not any version of the paper that has been put into english from scientisish , so non-scientifically minded people may find that link heavy going, but it is the paper in it's origional context.

HTH
Rabbut

 

[Axleuk]

If anyone whom may be reading this thread is wondering why we are contradicting "common knowlage" in the hobby by stating that Bactinettes with Nitrobacter as the primary nitrite oxidising bacteria is not using the correct bacteria and that Nitrospira type bacteria is what the porduct theoretically needs to work fully. To clarify to them, where this is comming from, and also to try and help Axle with his advanced reading on the topic, if you haven't already, I'd advise reading through the research paper Dr Hovanec wrote on the subject here This is not any version of the paper that has been put into english from scientisish , so non-scientifically minded people may find that link heavy going, but it is the paper in it's origional context.

HTH
Rabbut

Your having a laugh!! Bloody Hell, i got through the abstract ok enough, but fell after the first paragraph. Too many long words and abbreviations for my little brain to process.

Ummmm.... i'll take 'Criminals of the 80's for $300 please Alex'

 

[Efren]

well i haven't read the full article in this thread - -
so sorry to barged in - - i'll read them later..

i myself used Bactinettes - -complete day to day results on my journal
and so far so good - -

i'm not thoroughly done with the tests yet
so more to come ---

 

[rabbut]

Your having a laugh!! Bloody Hell, i got through the abstract ok enough, but fell after the first paragraph. Too many long words and abbreviations for my little brain to process.

I'll admit that I am also finding the full thing rather heavy reading, and I'm not going to pretend that I understand all of it, because I don't, but the abstract in any paper is supposed to sum up it's findings. The Nucleic acid sampling, Clone libraries and DGGE analysis sections in the Methods part keeps going way over my head. I'm getting very close to just skimming over this bit, and onto the section where Dr. Hovanec details the experimental tank set-ups...

 

[nickelplates]

I think there is a certain amount of missing the point in the discussion of Nitrospira V Nitrobacter. Nowhere in any of the research that has been quoted does anyone suggest that Nitrobacter cannot oxidise the Nitrite in an aquarium nor does anyone show that they cannot live, multiply and thrive in an aquarium filter at low concentrations of Nitrite, just that if Nitrospira are present they will outcompete and eventually overwhelm them so, in a mature filter, it will be Nitrospira that play this role. So just maybe when you add Nitrobacter to a new tank it does colonise the filter media, does multiply and does deal with the Nitrite. However it is clear from Havonac's research that it will not do so indefinitely as over time it will be replaced by the Nitrospira which will out compete it under these conditions. To anyone who cannot genetically analyse the species present the difference is irrelevant, they always have the required nitrifying bacteria throughout and everything will be fine. I'm not saying this is what does happen (how could I know) but it is certainly consistent with the research quoted here and explains why Bactinettes can work even though it doesn't contain the same bacteria that we find in a mature filter system.

You wouldn't expect Havonac to point this out as it would be revealing how someone could make a truly effective product without paying license fees to his employer!

 

[Axleuk]

I think there is a certain amount of missing the point in the discussion of Nitrospira V Nitrobacter. Nowhere in any of the research that has been quoted does anyone suggest that Nitrobacter cannot oxidise the Nitrite in an aquarium nor does anyone show that they cannot live, multiply and thrive in an aquarium filter at low concentrations of Nitrite, just that if Nitrospira are present they will outcompete and eventually overwhelm them so, in a mature filter, it will be Nitrospira that play this role. So just maybe when you add Nitrobacter to a new tank it does colonise the filter media, does multiply and does deal with the Nitrite. However it is clear from Havonac's research that it will not do so indefinitely as over time it will be replaced by the Nitrospira which will out compete it under these conditions. To anyone who cannot genetically analyse the species present the difference is irrelevant, they always have the required nitrifying bacteria throughout and everything will be fine. I'm not saying this is what does happen (how could I know) but it is certainly consistent with the research quoted here and explains why Bactinettes can work even though it doesn't contain the same bacteria that we find in a mature filter system.

You wouldn't expect Havonac to point this out as it would be revealing how someone could make a truly effective product without paying license fees to his employer!

I think the bottom line here is that both products whilst containing different nitryfying bacteria accomplish the same job over a given period of time. As you have implied, one will give you a tank that contains the same mature bacteria in a shorter period of time, and the other will kickstart this process and ultimately give you the same bacteria over a longer period of time, but both these products allow for the relative safe addition of fish if used correctly in a shorter period than a conventional fishless cycle.

 

[andywg]

I think there is a certain amount of missing the point in the discussion of Nitrospira V Nitrobacter. Nowhere in any of the research that has been quoted does anyone suggest that Nitrobacter cannot oxidise the Nitrite in an aquarium nor does anyone show that they cannot live, multiply and thrive in an aquarium filter at low concentrations of Nitrite, just that if Nitrospira are present they will outcompete and eventually overwhelm them so, in a mature filter, it will be Nitrospira that play this role. So just maybe when you add Nitrobacter to a new tank it does colonise the filter media, does multiply and does deal with the Nitrite. However it is clear from Havonac's research that it will not do so indefinitely as over time it will be replaced by the Nitrospira which will out compete it under these conditions. To anyone who cannot genetically analyse the species present the difference is irrelevant, they always have the required nitrifying bacteria throughout and everything will be fine. I'm not saying this is what does happen (how could I know) but it is certainly consistent with the research quoted here and explains why Bactinettes can work even though it doesn't contain the same bacteria that we find in a mature filter system.

The above is more than plausible. One should probably add that it is not just Hovanec's work on this subject which we rely on. I understand the points about low nitrite favouring Nitrospira spp and higher Nitrobacter spp comes from Regan, J.M. G. W. Harrington, and D. R. Noguera. 2002. Ammonia- and Nitrite-Oxidizing Bacterial Communities in a Pilot-Scale Chloraminated Drinking Water Distribution System. Applied and Environmental Microbiology 68:73-81.

You wouldn't expect Havonac to point this out as it would be revealing how someone could make a truly effective product without paying license fees to his employer!

I believe (from looking at the patent filed) that the patent is personally owned by Dr Hovanec, but may be wrong on this. The difference is, in effect, immaterial. I seem to recall that Dr Hovanec's studies initially started because they wanted to look into why traditional cultures did not seem to work.