cycling question

[MarinFlorin]

Hello guys!
A few weeks ago started to cycle one aquarium with the 'fishless method', using ammonia solution.
In the first weeks all good the ammonia dropped close to zero and I was adding daily until the nitrites(NO2) started to spike.
Now the problem is that the Nitrites are still high over 5ppm the amonia is going to 0 in less than 12 hours and the Nitrates(NO3) are huge over 100 ppm. I did this before but usually when the NO3 is starting to raise the NO2 ar dropping also,but for this tank is not happening. I add every 12 hours enough ammonia so I can raise it back to 3-5 ppm in order to keep the the other bacteria alive.(forgot the name - the ones which are transforming the NH4/NH3 in NO2). As far as I know as soon as I have so high level of nitrates in my aquarium it means that the second type of bacteria (the ones which trasforms the NO2 in No3) are present and the cycle should be completed.
Please give me any advice if you have any Idea of what I'm doing wrong.
Cheers!

[TwoTankAmin]

In a nutshell your problem is you are dosing way way too much ammonia. You are actually stalling your own cycle. I have written a nice easy to follow fishless cycling article for a general fish site which used to have major problems with members having cycling issues on the site. The method, if followed to the letter, is fail safe. It is a variation on the method suggested by Dr. Hovanec.

The major cause of cycling problems is actually too much nitrite. At 5 ppm (or mg/l) of nitrite as measured using the nitrogen scale, nitrite begins harming the process. As it goes higher this gets worse. But in the hobby out test kits tend to measure the nitrogenous compounds in our tanks using the total ion scale. think of this as measuring temp in F or C or distance in miles of kilometers. the scales are both accurate and can be converted to the other. The factor for nitrite is 3.28. That means 1 ppm of NO2-N will test on a hobby kit as 3.28 ppm of NO2. So, if the danger level to a cycle for nitrite as nitrogen is 5 ppm, a kit such as the popular one from API would show that as 16.4 ppm. But that kit only goes up to 5 ppm. This forces one to have to do diluted testing to get an accurate reading. The method in my cycling article, when followed, will prevent the possibility of nitrite ever getting close to 16.4 ppm and that means when the test kit maxes out, one need not worry about having too much nitrite or about doing diluted testing.

From the start to the finish of a fishless cycle done this way one will only be adding ammonia 5 or 7 times in a 4 - 5 week cycle and one of those additions is a snack dose at 1/3 the level of the other additions. None addition should ever result in more than 3 ppm of ammonia in a tank, I hope it is not violating the rules here to link you to my the article http://www.fishforums.net/index.php?/to ... his-first/

My advice to you is to do as large a water change as you can- 90s % is fine. Then test both ammonia and nitrite. You should get a 0 for ammonia and close to that for nitrite. My best guess is you are at the dose # 4 point in the directions. But your test readings after the huge water change will help you to know, You should be able to get your nitrite down well under 5 ppm. I would hope after the wc you will read less than .25 ppm of ammonia and under 1 ppm of nitrite. If you are not, wait to add ammonia until you are, and then follow the directions from there.

[MarinFlorin]

Wow thanks a lot!! Will try to do as you said! Will keep you updated! Cheers!!

[MarinFlorin]

Juat did a water change (big one) and the readings ar as follows: nh4/nh3 - 0, no2-1 ppm. I have Sera test kit. Shall I wait now untill the no2 is going to 0 or close and after I go to doze #4?
Cheers!

[TwoTankAmin]

whenever you test and ammonia is .25 ppm or lower and nitrite is clearly under 1 ppm, it is time to add another full ammonia dose (Dose #4) and then test in 24 hours.

If ammonia and nitrite both read 0 ppm, you are cycled. Do a large water change, be sure the water is the proper temperature, and add fish. The odds are this will not be the case quite this soon.

If ammonia and nitrite do not both read zero, continue to test daily. Whenever ammonia is again at .25 ppm or less and nitrite is clearly under 1 ppm, add the full amount of ammonia (Dose #5) and test in 24 hours. Follow this pattern of testing and adding (this would be Dose #6, #7 etc.) until both tests do read 0 ppm within 24 hours. The cycle should not take much longer to be completed and even with slower tanks one should not need to go beyond Dose #6 or #7.

You are about at the stage above. Your ammonia at 0 (i.e. less than .25 ppm) but your nitrite needs to come down a bit so it is clearly under 1.0.

What you should be able to figure out is about where your nitrite really was. If you changed 90% of the water and it reads 1 ppm after that, then it had to be at least 10 ppm before the water change. There is another issue adding too much ammonia can cause in a tank and that is the type of bacteria it selects for. Different strains of bacteria are best suited to specific ammonia r nitrite concentrations. The ones in our tanks are those best suited for handling lower levels of ammonia and nitrite. If we add too much ammonia when trying to cycle a tank, we can encourage the strains that do best at higher concentrations. This means as the tanks continues to establish, other stains must become established, those which work best at typical tank concentrations.

The most current research into ammonia oxidation deal with ammonia oxidizing archaea. These little guys have the greatest affinity for ammonia. This means they are able to thrive at the lowest concentrations. While more research is needed into this area and fw tanks, there is little doubt that they are present in well established tanks. The only question is how much of the ammonia processing they may be doing vs what is being done by bacteria. One this that is known for sure is they do not do as well in ammonia concentrations that are higher. So they may not actually become well established in tanks for some time after the initial cycling process.

Establishing nitrification in an aquarium almost always involves highish ammonia levels whether it is done with or without fish.

Kost of the early wrings on fishless cycling initially used higher and more frequent ammonia doses. Most of the early articles on the topic have since been revised by their authors to lower the recommended ammonia doing regimens. The ammonia additions are now much smaller. Even Dr. Hovanec's method only adds about 2.5 ppm at a time. (Note that his ammonium chloride product uses the nitrogen scale and dosing is 2 ppm NH3-N. 1 ppm NH3-N - 1.2 ppm NH3 and 1 ppm NH4-N = 1.3 ppm NH4.)

[MarinFlorin]

I did as you said above with the ammonia. Yesterday got 0 amonia and 0 nitrite and aded 3 ppm of ammonia. After 12 hours the ammonia was 0 or close and the nitrite 1 ppm. I will measure today again to see how is going with the nitrite. I didn't told you that durong the cycle I have added a lot of bacteria cultures which you find in pet shops and when I mean a lot is something like 100 times more than recomended dose. Don't know how much will this influence the cycle. The bacteria was added in the begining. For filtration I'm uing a mattenfilter and the aquarium capacity is 47,5 ltrs.
Will keep you updatd with the next measurements!
Thanks a lot for the above lecture. I will probably need to read it 2-3 more times to fully understand it!! biochemistry was not my thing but I understand a bit!
Cheers!

[MarinFlorin]

Just did some test (after 24 hours) and the results are like this:
Ammonia - 0, Nitrite-0, nitrate-10 ppm.
I believe that the tank is cycled. My question now is if I add 1/3 of dose daily untill will add fish??? Hopefully in the next days will have some fish inside the tank but as I understood still need to feed the bacterias. Can you please advise?? Thanks!!

[TwoTankAmin]

The nitrifying bacteria are way more hardy than most realize. In addition, they are not so easy to starve. For one they do not need to have ammonia every day. My usual suggestion for keeping a tank cycled while waiting for fish is to add 1 - 2 ppm of ammonia every 2-3 or days. The bacteria also have strategies for coping with nutrient and oxygen deprivation etc. For those that are science nuts here are three relevant papers on this subject:

Strategies of aerobic ammonia-oxidizing bacteria for coping with nutrient and oxygen fluctuations
http://onlinelibrary.wiley.com/doi/10.1 ... 170.x/full

Influence of Starvation on Potential Ammonia-Oxidizing Activity and amoA mRNA Levels of Nitrosospira briensis
http://aem.asm.org/content/71/3/1276.full


Long-term storage and subsequent reactivation of aerobic granules
http://www.sciencedirect.com/science/ar ... 2408002009

Basically the bacteria can go dormant. They can last this way for a fairly long time and then return to viability. This is all mitigated by what condition they are in when forced to go dormant and then how long they remain that way. The better shape they are in at the start, the faster they revive and resume activity. And the longer they are dormant, the longer it will take for them to return to working at the same level they did before they went dormant.

Recent discoveries indicate that another microorganism, the Archaea, are also able to oxidize ammonia. They were discovered in the substrate of a tank at a public aquarium. It turns out they are ubiquitous in all environs. They had been mostly considered to be extremophiles prior to the discovery. They have a higher affinity for ammonia than any of the autotrophic bacteria (this means they can thrive at the lowest levels of ammonia). It is likely that they are also present in many of our fw tanks, However, when they are, they usually show up later on because the amount of ammonia we get/use when cycling is too high for them to thrive. More research is still needed on this, imo. However, there is little doubt they are present in some portion of well established FW tanks.

[dw1305]

Hi all,
I'd say straight away that I'm not a fan of adding ammonia to "cycle" aquariums, there is a more complete discussion in this thread "Using deep gravel...."<http://www.planetcatfish.com/forum/view ... =4&t=41038>.

the Archaea, are also able to oxidize ammonia...........It is likely that they are also present in many of our fw tanks, However, when they are, they usually show up later on because the amount of ammonia we get/use when cycling is too high for them to thrive. More research is still needed on this, imo. However, there is little doubt they are present in some portion of well established FW tanks.

New DNA/RNA techniques for investigating microbial communities are discovering a whole raft of different organisms that oxidize ammonia. I think the evidence is stacking up all the time that the Archaea are the primary oxidizers of ammonia.

"Relative contribution of of archaea and bacteria to aerobic ammonia oxidation in the environment" <http://citeseerx.ist.psu.edu/viewdoc/do ... 1&type=pdf>

"Evaluation of autotrophic growth of ammonia-oxidizers associated with granular activated carbon used for drinking water purification by DNA-stable isotope probing"<http://www.sciencedirect.com/science/ar ... 5413008464>,

"Low-ammonia niche of ammonia-oxidizing archaea in rotating biological contactors of a municipal wastewater treatment plant" <http://onlinelibrary.wiley.com/doi/10.1 ... 786.x/full>

"Aquarium Nitrification Revisited: Thaumarchaeota Are the Dominant Ammonia Oxidizers in Freshwater Aquarium Biofilters"<http://journals.plos.org/plosone/articl ... 23281-g004>

&

"Nitrotoga-like bacteria are previously unrecognized key nitrite oxidizers in full-scale wastewater treatment plants"<http://www.nature.com/ismej/journal/v9/ ... 4158a.html>.

cheers Darrel

[TwoTankAmin]

The archaea do not dominate during a fishless cycle, the ammonia levels are too high. They wont dominate during a fish in cycle either for the same reason. And where archaea may be doing what is still open to debate. I can offer studies that show the bacteria are dominant. The most common way of trying to measure the archaea vs the bacteria is to measure bacterial and archaeal amoA. But one problem here is it has been discovered that there are archaea which possess amoA and are not doing ammonia oxidation. Here are a few studies to look at.

Ecophysiological Characterization of Ammonia-Oxidizing Archaea and Bacteria from Freshwater
http://aem.asm.org/content/78/16/5773.long

Heterogeneity of ammonia-oxidizing community structures in a pilot-scale drinking water biofilter
http://www.sciencedirect.com/science/ar ... 0512000674

Thaumarchaeotes abundant in refinery nitrifying sludges express amoA but are not obligate autotrophic ammonia oxidizers
http://www.pnas.org/content/108/40/16771.long

Community structure and distribution of planktonic ammonia-oxidizing archaea and bacteria in the Dongjiang River, China
http://www.sciencedirect.com/science/ar ... 0814001223
(I can only see the abstract here.)

As far as I can tell there are a total of three studies on AOA vs AOB in aquariums. Two are research papers and the third is a master's thesis (https://www.uwspace.uwaterloo.ca/bitstr ... sequence=1). All three have a few things in common that make me dubious of the conclusion that AOA are the dominant ammonia oxidizers in aquariums, especially fw.
1. Laura Sauder is involved with all 3 of them.
2. The are very limited in the number of tanks as well as the geographic locations of the tanks sampled.
3. AOA were not always the dominant AOO in all tanks in the studies.
4. No substrate sampling was done in any of them.
5. The studies quote the 1996 paper by Dr. Hovanec et. al. to show " Nitrosomonas spp. were undetected in freshwater aquaria [5]" (from http://journals.plos.org/plosone/articl ... ne.0023281). The problem with this is in a subsequent paper published in 2001 dr. Hovanec et. al. discovered:

Enrichments of the AOB strains were added to newly established aquaria to determine their ability to accelerate the establishment of ammonia oxidation. Enrichments containing the Nitrosomonas marina-like AOB strain were most efficient at accelerating ammonia oxidation in newly established aquaria. Furthermore, if the Nitrosomonas marina-like AOB strain was present in the original enrichment, even one with other AOB, only the Nitrosomonas marina-like AOB strain was present in aquaria after nitrification was established.

from http://aem.asm.org/content/67/12/5791.full

The second study directly contradicts the idea that Nitrosomonas were undetected in freshwater aquaria. The second paper by the same researcher identified Nitrosomonas in tanks some 5 years after his initital paper and 10 years before the Plos One paper. So that information was readily available to the researchers yet they chose to quote the older supplanted research.

Next, archaea are 10 to 100 times smaller than AOB. The amount of ammonia a single archaea can oxidize vs a single bacteria is not likely to be anywhere near the same. This means it takes a much greater number of AOA than AOB to process any given amount of ammonia. And this means one should find more AOA and thus more archael amoA. I am unconvinced that finding more AOA AmoA genes than AOB amoA genes indicates the archaea are dominant.

Some AOA are also thought to be mixotrophic. They still have an amoA gene, but they may not be using it to process ammonia.

I do feel archaea are likely to be present in many tanks but that is far cry from stating they are the dominant ammonia oxidizers in most tanks. A heck of a lot more research is needed before this can be concluded

Darrel, while you may not be a fan of using ammonia and fishless cycling, you are in the minority. This has become the predominant way of cycling tanks over the last decade. It is easy, it wont harm fish and it works. For the new fish keeper it is the best option, imo. This doesn't mean there are not other ways, but they will be more complicated and harder for a beginner to do, especially since most of them want fish ASAP.

And then what about all the folks on this site who spawn and grow out all sorts of catfish in bare bottom tanks? What use is a deep gravel bed in a bare bottom tank? These tanks must be cycled too. I am not saying what you prefer wont work for you, but I would never try to get a 1st time fish keeper to try it in their first tank.

Lastly, even if one accepts that archaea are the ultimate dominant AOO in a tank based on the 3 studies I metioned above, they indicate AOA are not there in any great number during cycling. Rather they tend to be present in greater number months after a tank is cycled and stocked. So bacteria would still have a place in most tank startups.

[dw1305]

Hi all,

The archaea do not dominate during a fishless cycle, the ammonia levels are too high.

We aren't going to agree, but this is really the heart of the matter. Why add extra ammonia when it produces a different microbial community to the one that will be present once the filter has matured?

Darrel, while you may not be a fan of using ammonia and fishless cycling, you are in the minority. This has become the predominant way of cycling tanks over the last decade. It is easy, it wont harm fish and it works. For the new fish keeper it is the best option, imo. This doesn't mean there are not other ways, but they will be more complicated and harder for a beginner to do, especially since most of them want fish ASAP.

And then what about all the folks on this site who spawn and grow out all sorts of catfish in bare bottom tanks? What use is a deep gravel bed in a bare bottom tank? These tanks must be cycled too. I am not saying what you prefer wont work for you, but I would never try to get a 1st time fish keeper to try it in their first tank.

The whole point is that I want to encourage new fish keepers to have a tank with plants, a substrate and plenty of dissolved oxygen. I want them to be "fish keepers" not "fish havers".

Aquarists starting a new tank should always have established filter material they can use, and if new fish keepers can't wait a few weeks for their tanks to mature, then you would have to question whether they should have fish at all.

Even if you accept that adding ammonia and monitoring changes in NH3/NO2/NO3 is a good idea, there is the problems with the accuracy of the test kits available to us.

The real problem here is the whole concept of "cycled" via "non-cycled". It isn't a binary division where we flip from one state to the other, but a continuum. The principal metric in ammonia oxidation is oxygen (we've gone from NH3 to NO2 to NO3), which is why water quality is estimated via a "5 day BOD test". <http://en.wikipedia.org/wiki/Biochemical_oxygen_demand>.

Lastly, even if one accepts that archaea are the ultimate dominant AOO in a tank based on the 3 studies I metioned above, they indicate AOA are not there in any great number during cycling. Rather they tend to be present in greater number months after a tank is cycled and stocked. So bacteria would still have a place in most tank startups.

I don't know whether the archaea or bacteria are the most important organisms in ammonia oxidation, but what the research has shown us is that things are a lot more fluid than was originally thought.

Ecology is all "shades of grey", and tanks that are reliant on microbial nitrification in a bio-filter will always have this as a "single point of failure".

If you have a tank with multiple sites for nitrification, and plants with the "aerial advantage" <http://www.planetcatfish.com/forum/view ... hp?t=39714> (of access to aerial CO2 and oxygen levels), you have a simple and robust system which will be able to respond quickly to increased ammonia levels.

cheers Darrel

[TwoTankAmin]

Please take how I state things as being well intentioned. I think a little sarcasm may creep into things here, so I apologize in advance if I accidentally offend anybody, it is not intentional.

DO- tell the denitrifying bacteria they need DO. And then what about anaerobic ammonium oxidation (anammox). Are you sure there is none of this going on in a deep bed in a tank?

Darrel- I would love to see how you advise a newbie who asked for help in setting up their very first tank- a 20 gal. long. How deep should we suggest the substrate be here since the tank is 11.5 inches from the bottom class to the the underside of the lip where the glass top will rest. She will have some corys in this tank, so we will need to leave at least a 1/2 inch of air space above the surface. So this person has a scant 11 inch depth with which to work. Oh yes, this person is young and has to be very cost conscious. Deep gravel bed, I think not. Lots of live plants and ferts etc.? I don't think so. They need another way.

Here is another person very excited about their new tank. They have hard water with a high pH and they heeded the advice not to change ones tap parameters but rather to keep fish that will thrive in it. So what do we suggest to this person with pH 8.5 water with a TDS of about 350 ppm. What plants are we going to suggest here? I know we cannot do a fish in cycle here since 1 ppm of total ammonia in this tank which will be kept at 78F would have an NH3 component of 0.1607 ppm. Since 0.05 is considered the red line for NH3, we sure do not want to expose fish to even .25 ppm of total ammonia for any amount of time.

Most of the members on this site are not new fish keepers. Many have multiple tanks and also spawn their fish. Most of us are not new to fish keeping. The current membership here is currently shown as 10,885. The two biggest general fish sites in English which are both loaded with newbie hobbyists have their current memberships showing as 115,957 and 98,024. There is a huge different between those two sites and sites like PC in terms of the experience people have. Both those sites have over 1,00s of brand new fish keepers going to them every month for help and advice on setting up their first tank.

Newbie fish folks can rarely find items from an established tank to help seed theirs. I know this for a fact. They are often on a budget and need to be successful with the bare minimum of equipment etc. Moreover, ecology is a wonderful thing. One part of this is that the microorganisms have not read all the opinions, they just do what they do. The nitrifiers will colonize anywhere they can get what they need. This means they are not limited to a filter, they are all over a tank. Take the typical new keeper. They may have a filter which is too small, which is not optimized in terms of media and then they may either clean it too often so they lose bacteria or they do not clean it often enough and flow slows due to clogging. Their filter is not going to be the best place for bio-filtration. But the ammonia is still being created. What happens is the bacterial colonies elsewhere in the tank will grow to compensate for any lack in the filter. All they need is circulation for this.

Consider the recent initial discovery of the ammonia oxidizing Archaea. They were found on the substrate in a salt water tank at a public aquarium which had massive filtration. I am sure sw filters have been studied in the past. But the AOA were not discovered there.

Here is what I do know. If people use and follow the cycling article I wrote, they end up with a tank that is safe for fish in terms of ammonia and nitrite and they do so in about 5 weeks and they can fully stock the tank if they want. It uses ammonia to insure this is the case. It works. The fish go in, there is no detectible ammonia or nitrite and the tank stays safe in this respect for many years unless something accidentally occurs to kill off the bacteria/archaea or to overwhelm a tank with ammonia. And, as far as I am concerned, this is a good thing.

There are a lot of ways to do things in an aquarium. In the end, the goal is to create an environment that is "good" for the tank inhabitants and which the fish keeper is able to handle as well.

[dw1305]

Hi all,

DO- tell the denitrifying bacteria they need DO. And then what about anaerobic ammonium oxidation (anammox). Are you sure there is none of this going on in a deep bed in a tank?

If I have anaerobic denitrification in the substrate that is fine. Personally I have no more than 2" of sand in the tanks. If I have a lot of flow I mix some fine gravel in with it (<http://www.planetcatfish.com/forum/view ... hp?t=33623>).

Darrel- I would love to see how you advise a newbie who asked for help in setting up their very first tank- a 20 gal. long. How deep should we suggest the substrate be here since the tank is 11.5 inches from the bottom class to the the underside of the lip where the glass top will rest. She will have some corys in this tank, so we will need to leave at least a 1/2 inch of air space above the surface. So this person has a scant 11 inch depth with which to work. Oh yes, this person is young and has to be very cost conscious. Deep gravel bed, I think not. Lots of live plants and ferts etc.? I don't think so. They need another way.

They don't, 1" of sand blasting sand for the substrate, a few dead leaves (Beech, Magnolia or Oak are good) then add Horn-wort (Ceratophyllum) and a floater (Duckweed (Lemna minor) will do), and a HOB with a DIY intake sponge <http://www.planetcatfish.com/forum/view ... hp?t=35641>. Feed the plants (with any "off the shelf" fertilizer) if they need it (via the Duckweed index <http://www.planetcatfish.com/forum/view ... hp?t=36231>). Wait 4 weeks and add the fish. You could always add a potted Echindorus (http://www.planetcatfish.com/forum/view ... =6&t=40388), some rounded cobbles (<http://www.planetcatfish.com/forum/view ... hp?t=39436>) and dead wood (<http://www.planetcatfish.com/forum/view ... hp?t=35930>), again I suggest "pick your own" for both of these.

Here is another person very excited about their new tank. They have hard water with a high pH and they heeded the advice not to change ones tap parameters but rather to keep fish that will thrive in it. So what do we suggest to this person with pH 8.5 water with a TDS of about 350 ppm. What plants are we going to suggest here? I know we cannot do a fish in cycle here since 1 ppm of total ammonia in this tank which will be kept at 78F would have an NH3 component of 0.1607 ppm. Since 0.05 is considered the red line for NH3, we sure do not want to expose fish to even .25 ppm of total ammonia for any amount of time.

Just use the tap water and the same approach as above. Horn-wort and Duckweed both do well at high pH, other floaters like Pistia (Water Lettuce) and Amazon Frogbit (Limnobium laevigatum) will grow at any pH. Other plants which prefer hard water are "Vallis" Vallisneria spp., Cryptocoryne balansae, Sagittaria subulata & Guppy grass ( Najas guadalupensis). If you aren't sure about a plant if it is listed in the Tropica "Easy Plant" range (<http://tropica.com/en/plants/>) it is likely to grow.

Most of the members on this site are not new fish keepers. Many have multiple tanks and also spawn their fish. Most of us are not new to fish keeping. The current membership here is currently shown as 10,885. The two biggest general fish sites in English which are both loaded with newbie hobbyists have their current memberships showing as 115,957 and 98,024. There is a huge different between those two sites and sites like PC in terms of the experience people have. Both those sites have over 1,00s of brand new fish keepers going to them every month for help and advice on setting up their first tank.

Newbie fish folks can rarely find items from an established tank to help seed theirs. I know this for a fact. They are often on a budget and need to be successful with the bare minimum of equipment etc. Moreover, ecology is a wonderful thing. One part of this is that the microorganisms have not read all the opinions, they just do what they do. The nitrifiers will colonize anywhere they can get what they need. This means they are not limited to a filter, they are all over a tank. Take the typical new keeper. They may have a filter which is too small, which is not optimized in terms of media and then they may either clean it too often so they lose bacteria or they do not clean it often enough and flow slows due to clogging. Their filter is not going to be the best place for bio-filtration. But the ammonia is still being created. What happens is the bacterial colonies elsewhere in the tank will grow to compensate for any lack in the filter. All they need is circulation for this.

This is exactly why you have plants. They take up all forms of nitrogen and convert it into plant tissue, if you have more nitrogen they grow more quickly and are a darker green giving you a visual indication of the nutrient status of your tank. Their roots provide additional sites for nitrification, and when you harvest the plants you export the nitrogen. A floating plant is both easy to remove and has access to aerial CO2, which is why it is the "Duckweed Index".

Consider the recent initial discovery of the ammonia oxidizing Archaea. They were found on the substrate in a salt water tank at a public aquarium which had massive filtration. I am sure sw filters have been studied in the past. But the AOA were not discovered there.

Hundreds of previously unknown micro-organisms have recently been found by using RNA and DNA detection techniques, but it doesn't matter whether they are archaea or bacteria the whole point is that the situation is much more fluid and complicated than was originally envisaged.

Here is what I do know. If people use and follow the cycling article I wrote, they end up with a tank that is safe for fish in terms of ammonia and nitrite and they do so in about 5 weeks and they can fully stock the tank if they want. It uses ammonia to insure this is the case. It works. The fish go in, there is no detectible ammonia or nitrite and the tank stays safe in this respect for many years unless something accidentally occurs to kill off the bacteria/archaea or to overwhelm a tank with ammonia. And, as far as I am concerned, this is a good thing.There are a lot of ways to do things in an aquarium. In the end, the goal is to create an environment that is "good" for the tank inhabitants and which the fish keeper is able to handle as well.

I want people to enjoy their fish as well, but I don't want them to rely on test kits, or a filter that can be a "single point of failure".

The bottom line for me is that it isn't about what is possible, but it is about what is probable. If you like it is a "risk management" approach to aquarium care, where you build negative feedback loops and try and avoid single points of failure.

Planted tanks are stable and resilient.

cheers Darrel

[TwoTankAmin]

I am going to tell my oscar to please leave the plants alone, he must stop pulling them up, he must stop shredding or eating them. (I don't actually have one.)

And when, after reading the advice to fill their tank with plants, the newbie responds, "I have killed any plant I have tried to keep in my life. I am not willing to put live plants into my tank." what then? Or, I don't like sand so I wont use it..... What happens in the planted tank that has a serious plant die off? Single point failure?

It is very easy to tell people how to plant a tank. But newbies often fail to get it right initially. They will use the wrong types of ferts, they will dose improperly, they will have issues with lights and photo-periods. Many folks won't be able to afford some of these things or may not want to care for them. Some will want to keep plant eating fish. And then there are the stores where many people shop. Most pets stores have poor selections and often unhealthy plants. For many new fish keepers having live plants is a complication not a simplification.

I can and do keep tanks with no plants and no substrate as healthy as I keep a my well planted tanks. The fact that this is the case is all I need to know to realize one does not need either plants nor substrate to have a healthy thriving tank.

The bacteria in a tank can grow in a lot of places besides in one's filter. If a filter is too small or not maintained properly, bacterial colonies will expand elsewhere in a tank. All they need is flow that delivers the nutrients to them and a shady spot. Over time every biofilm will build up to the point of having some level of denitrification happening. One can actually work to encourage this to a greater extent. And, unless one uses rooted plants, the substrate will not be all that aerobically active since the oxygen levels fall off rapidly and after about 1/2 inch. The plants themselves are coated in bacterial biofilms, they arrive with bacteria on them. This is how things have evolved in nature

So what we see is that any planted tank, no matter how well planted, will still have nitrifying bacteria also working. In many cases bacterial growth will actually be encouraged/supported by plants. On the other hand, we can get the exact same nitrifying results in a tank with 0 plants soley from the microorganisms. As I see it, plants cannot thrive without nitrifying bacteria on them especially on/near their buried roots. However, nitrifying bacteria can thrive and keep a tank safe without any plants present. What does this tell us? There is another interesting factor here to consider in this respect. Which is it easier to kill off in a tank, the plants, the fish or the nitrifying bacteria?

The simple fact is, while some folks like having plants, there are more ways than planting to have a healthy fish safe tank. While one person wants to rely on a well planted tank, another may not. Both methods can work just fine. To argue that planted is the only or the best way to go, one must also show why a lack of plants would, in some way, be harmful or unsafe for the fish.

Please understand that I am not saying plants cannot contribute to keeping a tank safe from nitrogenous compounds or provide other benefits. What I am saying is they are neither the only, nor necessarily the best, way to filter all fw aquariums.

I forgot to ask- when you need to net a fish in a tank, where will that be easier to do- in a heavily planted tank or one with no plants.

[dw1305]

Hi all,
Last one from me in this thread.

So what we see is that any planted tank, no matter how well planted, will still have nitrifying bacteria also working.

True that is why I always specify "plant/microbe systems".

In many cases bacterial growth will actually be encouraged/supported by plants.

Yes, that really is the fundamental point, it is a synergistic situation, which is partially why it is more flexible and resilient than just microbes alone.

On the other hand, we can get the exact same nitrifying results in a tank with 0 plants soley from the microorganisms.

"Plant/microbe systems" are much more efficient at nitrification than "microbe only" systems. There has been a huge amount of scientific work, particularly in the developing world, in this area on "wastewater treatment", "vertical flow wetlands", "re-circulating aquaculture systems", "aquaponics", "phytoremediation" etc.

I know I'm not going to persuade every-one to keep planted aquariums, but every aquarium situation can have a floating plant like Pistia stratiotes, just type "Pistia wastewater" as a search term into "Google Scholar" and you get over 1300 academic papers just from the time period 2010 to 2015 <https://scholar.google.co.uk/scholar?q= ... s_yhi=2015>.

cheers Darrel

[TwoTankAmin]

I have read a ton of studies which encompass waste water treatment, drinking water treatment, aquaculture and then the limited number of aquarium related studies. What separates these environments in terms of how they process ammonia is the level of ammonia involved. The same strains of bacteria will not dominate in high ammonia vs low ammonia environments. This also applies when we look at pH water below about 6.0 pH. In acid water the bacteria must have receptors for NH4 as there is no NH3 to speak of. This is what is behind the idea that Archaea may be the ultimate nitrifiers in some tanks. They have the highest affinity for ammonia, i.e. they can thrive on the lowest levels, even those which are insufficient to support the ammonia oxidizing bacteria.

The same applies to the nitrite oxidizers. Nitrite levels will select between Nitrospira and Nitrobacter. The latter is at works in high ammonia loading such as waste water while the Nitrospira are what we see in tanks, aquaculture or a lot of drinking water treatment plants.

And the efficient part is really not all that relevant in an aquarium. Lets start with the fact that plants limit what one can keep. They require some level of additional equipment of supplies and add to one's workload to some extent- higher light tanks take more plant care than fish care. And in the end, the fish have no clue if one is using plants (with some bacteria on them) or only bacteria to clear ammonia. All that matters is the water is safe. And then what about the monetary consideration. Bacteria are free, plants (and their care) are not.

I am not arguing against having plants in tanks, what I am saying is they are not needed to keep any tank ammonia safe. If one likes the looks of plants, if one is willing to spend the money and time they entail, then by all means use them. On the other hand, if one wants to keep vegetarian fish, or fish that will trash plants or if one wishes to spawn fish in bare bottom plantless tanks, then one can do so with similar results having only bacteria. When we look at the hobby the world over, there are many places where it is difficult to find much of a selection of plants easily. My point is not that plants do not help, rather, it is that they are not required to make a tank safe.

There is one last point to make here. Not everyone who may want some live plants in a tank wants enough to handle most of the ammonia produced. I know I can get a tank cycled with no plants by adding a few doses of ammonia. I know when I am done I can add a full load of fish and they will be fine. On the other hand how much ammonia any plant species may handle is mostly not known and even if a newbie had the numbers, they could make no sense of them. In many cases the plant load for a beginner tank will not handle all the ammonia. I know of only one way to be sure if a planted tank that has not had any level of cycling or added bacteria might be safe for fish. You add 2 ppm (using an ammonia calculator for the needed amount). In 24 hours you test. If you get 0 ammonia and 0 nitrite, your tank is safe. If you do not, you either must add more plants, add bacteria or else do a bit of cycling to increase the amount of nitrifying bacteria in the tank.

I firmly believe that new fish keepers (with 0 experience) have a much greater chance when trying to use plants vs cycling of ending up adding fish to a tank which is not ammonia safe.

And since no one has answered this question yet, I will ask it again but phrase it a bit differently. Why is it you never find aquatic plants without nitrifying bacteria involved yet you can find systems where the bacteria handle the entire ammonia (and nitrite) load but do not foster the presence of plants. Consider two identical tanks which differ in one way- one uses lots of plants which fill the tank and get the job mostly done, or one can rely an a ton of bacteria to the job but we only know they are present because they may discolor the media? How much ammonia can a cup of bacteria eliminate versus a cup full of plants? Which of the two can survive the absence of all nutrients for a couple of months?

My advice to beginners will always be to cycle a tank using ammonia or at least top test the ammonia removal capacity in a tank by adding ammonia to see what happens. This works the same in a planted or a plantless tank.