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Standalone nitrogen cycle AKA Cycling a plantless, substrateless, filterless tank

9K views 36 replies 9 participants last post by  Hallyx 
#1 ·
OK, so it's a bottle.

I keep seeing all the talk about surface area and biofilms (more often called bacterial colonies here) and how they need to be maximized in order to be able to handle the ammonia created by the fish that we keep. A while back I did some calculations to compare the surface area of sand and gravel substrates of various grain sizes and various filter media and determined that the filter, as far as biological filtration is concerned, was a small part of the equation.This is sort of an experiment to see if even all that area is really needed in the first place.


Being a planted tank person I believe that plants are the easiest and best option but understand that not everyone wants to deal with plants for a variety of reasons. As a result, I skipped the whole tank cycling process. I understand that it still happens in the background even with a ton of plants and that it effectively becomes a dual system. I have since decided that I want to try creating a stand alone nitrogen cycle and do it in the simplest controlled environment possible, mainly to see what it is all about. I'm even using fish food that I would have otherwise thrown out... so it is a very cheap experiment.


Interestingly, there are more surface square inches of glass per gallon of water in my bottle than in my rectangular tank by a factor of 5 so I consider that compensates for the lack of filter and substrate to a certain degree.

I am using tap water at room temperature, fish food as an ammonia source with no substrate, plants, filter or circulation other than me moving it every once in awhile. I am aiming to keep the ammonia no higher than 1ppm. Water testing will be once per 24 hour period for ammonia and nitrites and nitrates only periodically. I am not concerned with nitrates and I really don’t want to have to do all that shaking anyway. The prime indicators of cycle completion are really the ammonia and nitrites dropping to zero with new ammonia added.

Tuesday I set up the jar, filled it with water and added four medium sized sinking pellets... probably too much for a small volume, but I can adjust as needed. Yesterday I tested ammonia at 0.25ppm. Right on cue. Nitrites were zero or at least unmeasurable with the test kit.

Jeff.
 
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#2 ·
Day 4

Tested ammonia, 1.0 ppm. I have not added any more food yet, obviously no need. I did a 2/3 water change to bring the concentration down to .3 ppm estimated as I want to keep it below the 1.0 ppm threshold. Easiest water change ever, pour out what I want to change and run the tap to fill it, all water changes should be so easy.

Nitrites are at 0.125 ppm if I have to put a number on it. The colour is sort of halfway between 0 and 0.25ppm. The water change reduced these as well, which is fine.

I still haven't tested for nitrates. The issue is that nitrates are produced 1 for 1 from ammonia. At least that is what I am lead to understand so the nitrate colour scale is 0, 5, 10, 20 etc, it is not nearly so sensitive as the ammonia and nitrite tests. Once I see them appear as non zero I can probably test every 5 days and get a better idea of their buildup.

The water appears a little murky but not terribly cloudy or anything. If it were a much larger volume perhaps the murky would be more apparent as there would be more of it to try to look through.

Jeff.
 
#4 ·
I'm on a well. Even so, I doubt that even the chloramine would inhibit the cycle being established by much. Even so, if I were doing this with city water I would still treat with prime anyway.

Bottle is about 1/3 of a gallon.

I hear that small water volumes are harder to get a cycle going, I doubt that now that I have done the math. It may be harder to keep it balanced with fish, I expect, as it takes far less ammonia to spike the concentration than in a larger volume but I have no plan to put fish in this.

Jeff.
 
#5 ·
I would be more interested in seeing how it worked using regular ammonium hydroxide. I expect it to work either way but decomposing fish food relies on a lot more bacteria then just then just ammonia to nitrate conversion. So I guess the question is what exactly are you trying to figure out? Nitrosomas and nitrospira/nitrobacter bacteria convert ammonia to nitrate and that its all. Breaking down fish food is going to rely on many other bacteria to produce the ammonia. I would wonder about oxygen levels when you have little more then surface diffusion going on and are trying for high bacterial activity. Low oxygen is going to slow the bacteria down.

I'm not sure why you are focused on surface area? Nitrogen fixing bacteria can colonize as heavily or sparsely as needed usually. I've personally never worried about surface area apart from the surface area of the water. Where aerobic nitrogen fixers colonize depends on a lot more then just surface area. I am one of those that believes the filter is often a large source of the nitrogen fixing bacteria in the tank, but that does depend on how both the tank and filter are setup. They certainly don't need the filter to colonize an aquarium, but the conditions in the filter are usually more ideal.
 
#6 ·
Seeing as I had ammonia within 24 hours of putting the fish food in the water, the initial bacterial activity is next to negligible in the whole picture, so the difference between using a pure ammonia source and fish food is one of neatness and maybe accuracy for the sole sake of accuracy. I can add food to bring the levels up or not change the water so soon but the 1ppm ammonia has been proven to be a threshold over which the nitrite oxidizers are inhibited from doing what they do best. I would have liked to do a side by side to prove this extends the cycle timeline but researchers have already done this.

Knowing how much food I added to bring the ammonia to 1ppm in an uncycled container lets me know how to judge the cycled container in testing afterwards to see how effective the biofilms are in this nitrogen cycle.

The surface area is not really of interest, just the fact that there is no additional surface area involved other than the glass container itself. I read about biological filter media and hold the opinion that they are not nearly as effective as advertised in many cases (although they don't really make claims that they are, just intimate that they are by their nature) and are not really needed in the first place. So rather than prove them not effective, it's easier to prove them unnecessary and therefore a waste of time and money... even if only to me.

I expect that not many will like my attitude toward well known and trusted brand name manufacturers' biological media products but that is my nature, to look under the marketing.

Also, I asked a couple of months ago for some timelines from people and their cycle setups and didn't receive any feedback. I just needed to establish what a timeline would be for my own curiosity, and I would have done it for that reason alone... it's just more fun to have other reasons as well.

Jeff.
 
#11 ·
Seeing as I had ammonia within 24 hours of putting the fish food in the water, the initial bacterial activity is next to negligible in the whole picture, so the difference between using a pure ammonia source and fish food is one of neatness and maybe accuracy for the sole sake of accuracy. I can add food to bring the levels up or not change the water so soon but the 1ppm ammonia has been proven to be a threshold over which the nitrite oxidizers are inhibited from doing what they do best. I would have liked to do a side by side to prove this extends the cycle timeline but researchers have already done this.

Knowing how much food I added to bring the ammonia to 1ppm in an uncycled container lets me know how to judge the cycled container in testing afterwards to see how effective the biofilms are in this nitrogen cycle.

The surface area is not really of interest, just the fact that there is no additional surface area involved other than the glass container itself. I read about biological filter media and hold the opinion that they are not nearly as effective as advertised in many cases (although they don't really make claims that they are, just intimate that they are by their nature) and are not really needed in the first place. So rather than prove them not effective, it's easier to prove them unnecessary and therefore a waste of time and money... even if only to me.

I expect that not many will like my attitude toward well known and trusted brand name manufacturers' biological media products but that is my nature, to look under the marketing.

Also, I asked a couple of months ago for some timelines from people and their cycle setups and didn't receive any feedback. I just needed to establish what a timeline would be for my own curiosity, and I would have done it for that reason alone... it's just more fun to have other reasons as well.

Jeff.
I agree with you regarding biological media and planted aquaria.(plant's can be excellent biological filter's)
Can't say this for tank's sans plant's,holding number's of large fish (cichlid's).
Mechanical media in these tank's, clog's quickly and is harder for water to flow through.(more frequent cleaning).IMHO
 
#7 ·
well I certainly agree biological media is a waste. Its not something I would bother picking to use in my filters. The only bio media I have is stuff that came with filters or I that bought 6 years ago. I do view them more as a marketing gimmick. I have some ceramic noodles(rena or fluval brand) that have been in constant use for 6 years. Yet when you hit one of them with a hammer the inside is still nice and dry and as white as when I bought them. I have never seen anyone prove they function any better then standard sponges/floss. I've always preferred good sponges and floss over any other media. I keep wanting to buy a bunch of poret foam but keep talking myself out of it =/
 
#8 ·
I just did the ceramic noodle test a week or two ago and found the same thing... although I intentionally broke it expecting that result.

Poret foam, interesting cell structure. It just looks like custom cut foam unless you look closer but is it that much better? It reminds me of the filter foam used in small engine carburation.

Jeff.
 
#9 ·
Poret foam is said to be better but I expect that could be questionable, since it is simply foam. Its actually not that easy to find customizable open cell foam for the aquarium. A number of filters use/sell just one pore size when it comes to sponges/foam, it may work for some, but filters run a whole lot better with various sizes. Any filter running 10,20,30ppi foam, and floss is going to filter and polish water very well both biologically and mechanically. Poret foam is more rigid then any other foam I have come across, that is the most noticeable difference to me anyway. When ever someone wants a hamburger mattenfilter it is the go to foam for that. But far as I know both the foam and that filter design came from Germany so its not that surprising. I mainly want it just so I know pore size and it is sold in easy customizable blocks or sheets. Its not like foam goes bad or needs replacing regularly. Its pretty affordable if you have lots of tanks, I just don't.... yet. I do have a couple of unused canister filters I got really cheap that need media and I would rather not buy the over priced pads sold for them. I have a habit of collecting equipment:roll:. The US seller of poret foam moved close to me recently. Which means I will probably end up buying some if they start coming to some of the local club events around here, one way to get out of shipping costs lol.
 
#10 ·
Day 7

Interesting test results yesterday. Ammonia at 1ppm, it seems to be peaking at 1 each day. Nitrites have dropped to zero but I haven't tested yet today to see if they are steady zero. I was going to test nitrates every five days but maybe I'll add one in today to see if there are any yet.

It's too early to tell if this is the telltale nitrite drop. I should dump the water altogether and add fresh food, I haven't had to add any yet as the ammonia levels have remained high... in fact I could have done with less food to start with an brought it up gradually to eliminate some of the water changes... not that they are hard.

I might start another bottle to produce ammonia laden water to add to the first jar so I can better fast the ammonia is dealt with. Easier to see a static 1ppm concentration and time the disappearance than try to judge based on constantly decaying food. I would sooner do this than go buy ammonia for no other reason than I don't have time to go looking for a pure source but the pure source may have been more revealing of what is going on.

Jeff.
 
#12 ·
Day 8

Ammonia back to 1ppm, nitrite still at zero so that test was not a fluke. Nitrates at non-zero.

The highest the nitrites tested at was 0.25ppm. If I assume that that concentration is what is being oxidized in a 24hour period and the ratio of ammonia to nitrite to nitrate is a 1:1:1 (I don't know but is think that it may be) then it might be safe to say that the nitrates could be as high as 1ppm due to the four days since the first nitrite appearance and they seem to be oxidized on the fly now. The colour scale is not that demarced to tell if non-zero is 1 or less. I'll know better in a few days based on where it rises to and how fast.

The 1:1:1 would also suggest that the ammonia is being oxidized at the same rate as the nitrates are being produced so my ammonia production is still outstripping the jars bio capacity which is apparent by the daily rise to 1ppm anyway.

Jeff.
 
#13 ·
Day 9

I guess I could have called the thread "The Seven Day Cycle". Nitrites are still zero after three days. I haven't retested nitrates yet but I expect that they are slowly climbing.

The only reason that the ammonia levels keep returning to 1ppm is due to the food still in the bottle decomposing. I guess I was a little heavy handed with the food considering the size of the jar. No real issue as I was able to keep the ammonia concentration at or below 1ppm.

I measured 1ppm again today and I removed the fish food by just running the water through a coffee filter. I then returned the ammonia laden water back to the jar to see how long it takes to drop to zero. If it does, the cycle is established and has been for the last three days.

More testing to come.

Jeff.
 
#14 ·
I'm surprised that you chose fish food for your experiment. Ammonia would have been a better control.


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#15 ·
True, but I had fish food on hand and didn't feel like going looking for a pure ammonia source. I was curious about the food decomposition as well, I mention that below.

I haven't posted anything new as not much has changed.

So, still in process, day 31.

I did test the water 5 days ago and the ammonia was down to 0.5ppm from 1ppm on it's own. The issue is that I used fish food to bring the ammonia up and water changes to keep it at 1ppm or less. I only ever added food once and when I filtered it out using the coffee filter after the cycle was established, I could not get it "clean" so there were still minute particles decomposing which has been driving the ammonia production even since the filtration. If I had used pure ammonia I could have just stopped adding it.

I was curious to see how the food decomposed over time and saw that ammonia was present within 24 hours, 0.25 ppm, and in 4 days it reached 1ppm and required water changes to keep it at or below 1ppm thereafter... until I filtered the food out.

Today it is slightly lower, somewhat under 0.5ppm and the nitrates are between 0 and 5ppm, in the lower end of the range. I also did a sniff test, I stopped doing that pretty early on as the smell was pretty nasty. Today there is no bad odour, in fact there is really no discernable odour at all and I have a pretty sensitive sniffer. I won't be doing a taste test anytime soon, duckweed is one thing.

Once it is down to zero on it's own (all the food is decomposed) I will add another ammonia source to test it... it might still be fish food but it would be representative of what might be expected if there were some teenie tiny fish in there.

I could just dump it and refill with clean water and it would serve the same purpose but I wanted to see if the jar would still handle the overload that is in there now. I also wanted to leave it this way to see how much the nitrate concentration rises without water changes... although there may be no empirical measure (#ppm ammonia in = #ppm nitrate out) it will serve to demonstrate the system efficacy. Actually, I would like that measure as I think it is a 1:1 ratio but I don't know for certain. With no plants or fish I could measure this well enough... I may will look for some pure ammonia after all so I can do just that.

Jeff.
 
#16 ·
Day 45. About 6 and a half weeks.

Ammonia is zero... Not sure when it bottomed exactly as I haven't tested in 14 days.

Nitrate is 5ppm

There has been no water added or changed since day 28 when the ammonia stopped climbing.

I am going to replace the water this weekend and add a very small amount of fish food to see if the system can stay ahead of a very small load. I may see about picking up some ammonia if I get a chance then I can change out the water to specifically test controlled ammonia concentrations now that the cycle is fully established and proven to be able to handle some ammonia on an ongoing basis.

I am at the point of considering that the nitrifying bio films that develop in a tank will grow to meet the load we introduce with the fish and associated wastes without the need to try to provide additional surface areas for them to grow on. Considering that, by default, we already provide a substrate, various ornaments, rocks, driftwood and filters with some porous media as well as some form of circulation to make the whole system more efficient, there really is no need to be concerned about adding any bio film friendly media.

I am of the opinion that the various bio friendly mediums (bio balls, ceramics and what not) do not actually do what they claim any better than classic foam and floss while some don't do any of what they claim, and I still stand by that, but it is easier to be able to say that they are not needed in the first place.

Jeff.
 
#17 ·
Two weeks ago I replaced the water in the jug with fresh well water and added 13 small food pellets. I tested every few days for ammonia and never saw anything more than a very slight blush in the tube... What Imight refer to as "non-zero" which could as easily be attributed to the lighting as an actual ammonia reading. Today I tested and used outdoor natural light and it is definitely zero. So are the nitrites. Theres not much sense in testing for nitrates yet as the scale has much larger graduations and is likely to test very low.

The jug has a nice sustainable nitrogen cycle. I even did the sniff test and there is not only no unpleasant odour, but there is no odour at all. The pellets are all still in there as there is no help from fish or snails to break them down quicker.

Today I added one more pellet and will continue to add one every day or two to drive the ammonia production higher to see if I can force the cycle to become overloaded. One additional pellet is an approximate 8% increase in source material.

Jeff.
 
#18 ·
JDM, the results of this experiment would be really interesting to the people in the betta forums. It's very commonly believed that tanks smaller than 2.5 gallons can't hold a cycle and that therefore constant water changes (even as much as daily) are needed--there's even a sticky over there about it. If you wanted to post over there about your results, I think a lot of people would find it really helpful.
 
#19 ·
I think a lot of people would just blindly argue with it.... But I agree, I think many of the betta people need more exposure to fish keeping and a better understanding of the nitrogen cycle.


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#22 ·
I think the issue is that, in a typical betta tank, the fish waste is continually building up faster than the cycle can establish for that size of a load. Water changes aren't what is important, vacuuming the bottom is and I would suggest that anyone keeping bettas, or anything in a small tank, should have a sand substrate instead of gravel to make this easier to do and a very small diameter vacuum to make it easier to manage.

Water changes should be a function of Nitrate buildup, although there are other compounds that build up at the same time that should be removed, nitrates are the primary indicator we seem to all use. So if nitrate hits 10ppm, change the water and work a schedule around that. Just doing a very quick daily vacuum to capture waste with a small vacuum setup will allow the ammonia generated be minimal and can serve as the water change.

I kept 6 cherry shrimp in a 500ml container (0.13 gallons) for a month. I fed them every day and used a turkey baster to remove waste off of the bottom of the container. I added some floating plants so ammonia was not really an issue but all the shrimp survived and molted and grew. I never tested it for an established cycle as I knew that between the plants and daily waste removal (that amounted to maybe 10% water changes as well) the water would be fine. No filter, no substrate.

Jeff.
 
#24 ·
I just re-read some more of that thread that you linked Deanna.

Jaysee is probably correct that it would be argued against as the current guru (not intending any disrespect) makes his widely followed claims.

There's nothing wrong with changing the water as is outlined, but it isn't necessary and there's no science behind it.

"The reason for this is because by the time there is enough ammonia for your bacteria to start living there, it is already too toxic for your fish"

The organisms start to propagate as soon as there is ANY ammonia present. That's just what they do. I kept my jug at 1ppm or less and the cycle established in 7 days. If I had fish and was using Prime to de-tox the water and changed 50% of the water if it reached 1ppm or more, I would expect similar results and the fish would be fine.. although I would choose not to do a fish in cycle.
I like advice to at least be based on correct information even if that falsely based advice works for the given situation... it is misleading. This is why I decided to do the jug cycle experiment in the first place, to base anything I say about the nitrogen cycle on a tried and tested example seeing as all I did was toss in a bunch of plants and fish.Jeff.
 
#25 · (Edited)
I just read through some of that link. The water change schedule outlined is way over the top. Honestly, if you need to do more than one water change a week, your tank is WAAAAAAAAAAAAAAY overstocked.



Here's a gem from that thread

Doing a 100% change will not kill them instantly unless you scrub the walls/deco/substrate. They will slowly starve to death from the lack of ammonia/nitrite or whatever it is they eat that is present when a fish is producing said ammonia (and when bacteria produce then nitrite).
This just demonstrates their lack of understanding of the whole process. The bacteria aren't going to starve to death - that's just nonsense. Ammonia is produced in a tank at a steady rate, and is continually consumed.
 
#26 ·
I am not writing this to start a debate, but to understand the process and results. From what I have been understanding from your investigation a serious conclusion is that the filter is not necessary in planted, cycled tanks.

Is that a logical conclusion, in your eyes?
 
#28 ·
There really isn't much to debate, I'm just posting results and some conjecture here and there.

The short answer is yes... but not only in a planted tank, any water filled container that has an ammonia presence. I wasn't going out to prove a filter wasn't necessary but if I take it in that direction I might suggest that a filter could be ONLY to remove particulate for our viewing pleasure and to circulate the water. It (the filter) captures organics which are converted in the filter into ammonia, just as they would be in the tank itself, then circulated about so as to be exposed to many surfaces covered in our friendly nitrifying biofilms. They make the whole affair more efficient, not more effective, as the filter removes nothing from the system.

In my actual aquarium I have a canister filter that never gets touched except once every few months so it is obviously not capturing particulate to be removed from the system, it breaks down as all there is is brown water when it does get opened. As Jaysee found in his filters that sat for four months, his ammonia levels were 4ppm or higher. These filters are full of decomposing material and the nitrfying organisms were not enough to deal with the ammonia load even though they were active on an aquarium, far from it.

I might suggest that further extrapolation may point to filtration through a canister or HOB not being necessary but that the circulation may be the sole important factor involved. A sponge on a powerhead may be just as effective as a canister filter seeing as the whole "needing the surface area in a filter" may be a false need. Certainly special bio media is a white elephant for more reasons than just not being necessary.

My initial goal was to see if a bare tank would support an effective nitrogen cycle as part of a followup from all the hype about bio-media added to filtration, bio-balls, ceramics etc. It was also to be able to know what actually goes on in the process so I wasn't just parroting others' opinions and suspect anecdotal evidence.

So far my simple conclusion is that the nitrogen cycle only needs some surface, the glass, to work. I am going to push it to see just how effective it is, but not necessarily empirically.

My ultimate conclusion may just be that it really doesn't matter what anyone does, the nitrogen cycle does what it needs to do completely on it's own and that anything that we add beyond water, a source of organics and the glass in the tank is superfluous.

OK, maybe there is something to debate, but my side is started on some experimentation, not solely on opinion.

Jeff.
 
#27 · (Edited)
If there is sufficient amount of real estate for the bacteria to grow to a size that will handle the bioload in conjunction with the plants without a filter, and sufficient circulation in the tank to bring the food to the bacteria (and nutrients to the plants), and sufficient surface disruption to allow the gas exchange to occur, then yes, you do not need a filter. Filters are recommended because they take care of all three of those issues.
 
#29 ·
Update on the jar cycle status and a little open ended thinking.
Ammonia = 0
Nitrite has been zero since day 7, even after the fresh water change and food addition
Nitrate = 1 (as much as a colour shift can look like a 20% difference from zero)

Still adding one tiny pellet a day and looking for the point where the ammonia levels may overshoot the capacity for oxidization. Seeing as I am gradually adding to the decomposing food in the jar and seeing as it takes a long time for food to decompose to nothing, the ammonia production will be increasing which, if slow enough, may allow the jar biofilms to grow in sync with the increase and proving that the jar may be capable of a far greater nitrification capacity than first I considered.

I begin to wonder where and why this huge emphasis on increasing surface areas in the aquarium world came from.

Jeff.
 
#30 ·
I begin to wonder where and why this huge emphasis on increasing surface areas in the aquarium world came from.

Jeff.
My guess is from keeping tanks stocked with fish :)

It's easy to determine if you don't have a large enough bacteria colony (not enough surface area) - you'll have chronic ammonia/nitrite issues. Otherwise, the tank will be in equilibrium. Fish do grow over time though, so something that may work while the fish are small may not work when they get big.


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#32 · (Edited)
This is a pretty fascinating read, JDM.

This should seem like an obvious answer from your posts, but just to confirm: you're not finding that doing water changes removes any significant amount of 'floating' bacteria to impact the established cycle?

Also, do you feel that plants and/or clean-up crews (snails, shrimp, etc) would be necessary to further break down food waste and reduce the need for vacuuming, or has this not presented a problem for you since ~1 month when you declared it cycled?

I like this simple experiment you're doing. This will have me keeping a closer eye on my tanks, feeding habits, and levels. Perhaps they are more stable than I had given them credit for, and would be fine with less water hauling on my part.

I think I'm still going to run some sort of powerhead/sponge filter in my tanks just to create water movement and surface agitation, and I wouldn't run a bare powerhead because I mostly deal with smaller fish/inverts that could get sucked in so there would be some sort of sponge pre-filter regardless.

That leads me to one more question: do you feel that this sort of sponge in the aquarium could actually cause issues specifically because it concentrates nitrifying bacteria, which makes it vulnerable to disruption during cleaning or when it eventually has to be replaced?

Edit: Actually, that's not my last question.

Do you feel that this sort of mechanical water movement is necessary to aid in oxygenating deeper water in taller tanks? If I could eliminate the need for powerheads, either through just airstones or heavy planting near the bottom of the tank or something, I wouldn't need to worry about pre-filters/diced shrimp.

Also, do you feel that surface agitation is necessary to break up the biofilm that can form on the surface, which may inhibit gas exchange on the surface? Specifically, I see this biofilm a lot in my tanks with bubblenesters (I think they might intentionally do this to build their nests) and in addition to gas exchange, I also worry about the effect on them when they surface to breathe. I try to remedy this by either having a powerhead near the surface or a sponge filter/airstone bubbling up.

I realize the last two questions here aren't directly related to cycling, but they would help me determine what sort of equipment is necessary in my tanks, which changes the amount and nature of biomedia that I incidentally have in them.
 
#33 ·
This is a pretty fascinating read, JDM.

This should seem like an obvious answer from your posts, but just to confirm: you're not finding that doing water changes removes any significant amount of 'floating' bacteria to impact the established cycle?
No, the organisms (bacteria or archeae as the case may be) are not active when they are floating as the bio film that adheres them to the surfaces is also the method of food capture and transport. I replaced the entire volume of water, gave the jar a slight rinse and filled it with fresh water, added some new fishfood and the cycle ticked right along as if I never touched it. I am going to do a chlorine test sometime and I fully anticipate the same result, no affect to the biofilms.

Also, do you feel that plants and/or clean-up crews (snails, shrimp, etc) would be necessary to further break down food waste and reduce the need for vacuuming, or has this not presented a problem for you since ~1 month when you declared it cycled?

I like this simple experiment you're doing. This will have me keeping a closer eye on my tanks, feeding habits, and levels. Perhaps they are more stable than I had given them credit for, and would be fine with less water hauling on my part.
I'm not suggesting that anyone do less water changing, that is not my point at all. In the jar I still only have water and fishfood, no plants, substrate filter etc. It's not much to look at, just a jar of water.

In my aquarium, I no longer do any vacuuming and there is very little buildup, which is why I stopped, nothing to vacuum. I had one stretch of 5 weeks (don't tell anyone, it's embarrassing) where I was unable to do water changes (long story) and the nitrates never climbed past 5ppm, no mulm buildup... I didn't even take out any dead plant material. While I can let it ride, I would rather not. There I have three or four kinds of snails, shrimp and the fish. I wouldn't be without them and I am sure that they plat a large part in keeping everything breaking down a lot quicker.

I think I'm still going to run some sort of powerhead/sponge filter in my tanks just to create water movement and surface agitation, and I wouldn't run a bare powerhead because I mostly deal with smaller fish/inverts that could get sucked in so there would be some sort of sponge pre-filter regardless.

That leads me to one more question: do you feel that this sort of sponge in the aquarium could actually cause issues specifically because it concentrates nitrifying bacteria, which makes it vulnerable to disruption during cleaning or when it eventually has to be replaced?
Disruption during cleaning is a non-issue. Replacing it... potentially but it really depends upon the aquarium system. Worst case, a planned replacement may just require the use of something like Prime to handle any immediate spikes until the system settles down. No worse than changing regular filter media. With plants, this is of far less an issue as they can easily take up the slack, the more the merrier.

Setting up a replacement sponge in a container and cycling it ahead of time can avoid the whole issue.

Jeff.
 
#34 ·
Tests as of day 69 or 24 since full water change and cleaning.

I'm due for testing today but last test day was still the same... nitrates are climbing slowly. Based on the colour shift it looks like over 1ppm four days ago.

I'm still adding food pellets and still have not reached the ammonia loading capacity.

I was going to do a test on a larger tank with just sand to see how much longer the cycle might take to establish but Bigdawg355 kindly did this part for me. No, he didn't know he was filling that slot, he just happened to be doing what I was going to do when he posted that he was doing just that and I already knew that doing as I suggested was going to be much faster for him and let me do the experiment by proxy.

He setup a 10 gallon with sand and kept the ammonia levels at or below 1ppm (other than an initial overdose which is a negligible factor so early in the process) and managed to establish a fully active nitrogen cycle in 9 or 10 days. That is a far cry from the typical 4-8 weeks reported by others using similar methods and higher levels.

"Ok so for the last 3 days my ammonia has been dropping to zero in a 24 hr period so today I tested nitrAtes and nitrItes results were Ammo 0
NitrItes 0
NitrAtes 5.0
Is this tank somehow already cycled? It's only been 12 or 13 days."

Read more: http://www.tropicalfishkeeping.com/freshwater-aquarium/does-bio-zyme-work-232001/#ixzz2aq40XtlD

http://www.tropicalfishkeeping.com/freshwater-aquarium/does-bio-zyme-work-232001/#ixzz2aq40XtlDYup, that's a cycled tank.

The difference between our two setups would be the volume, glass surface area and the sand and filter in one.

The volume difference between the 10 gallon and my 0.13 gallon is close to 80:1

The surface area (glass only) difference is only around 20:1... the larger the volume the less relative glass surface area to unit volume there is.

The sand, assuming an average grain size of 1/64" and a depth of an inch, would yield a surface area of about 36,000 square inches... I'm going to discount the filter at this point as it is an HOB and the additional surface area will be a pittance compared to sand (I did the math on that some time ago for another purpose). I would assume that the effective use of this as a working nitrification bio film support might decrease from 100% at the top to as low as 0% at the bottom (although I doubt it's that poor until it gets to 3" deep) due to reduced water flow over the areas which would be similar to having only 18,000 square inches in a moving sand bed. This is still more than 15 times the surface area of the glass alone and makes me see the benefit of a moving sand filtration system... if the efficiency can be increased to use 100% of the sand in the process ... well, that's a whole other topic...

Given that my 0.13 gallon tank setup in 7 days I would have thought, for no other reason than having to decide on some sort of outcome, that any larger tank might take a lot longer. I based this loosely on the fact that nobody seemed to report cycle times of less than a month... I can't think of any so far, other than me and the Dawg. So I was pleasantly surprised that the cycle time is close enough to the same given the huge variation in volume and surface areas.

A small jar with water only and a 10 gallon tank with sand both cycled in approximately the same time frame... 7 and 9 days respectively.If I extrapolate based on these two tests I would expect that going larger again would yield still similar timelines and say that you can probably cycle any tank with a substrate of any sort without consideration to any additional filtration quickly and effectively and the entire process timeline and efficacy is not determined by how much surface area is supplied at all... it just happens at a particular rate.

We don’t really understand exactly where these nitrifying micro organisms come from but it is likely that they are already dormant and present in the water and take advantage of the tendency of any surface to develop a film conducive to the attraction of biologicals (this is the bane of the medical industry even with their shiny steel and slippery plastics) and they just adhere then feed, grow and propagate. Due to the likely pre-existing nature of these critters, I also expect that the larger the water volume, the more of these dormant micro organisms there are. Then when they attach themselves and binary fission kicks in, the timeline from start to finish will always be similar given a similar water source no matter the volume... at least within our aquarium sizes.

My conclusions thus far agree with my initial hypothesis:

We are supplying far more surface area than is needed in just a typical setup for bio film development to establish a nitrification cycle. This makes the various points about the real lack of efficacy of these bio friendly media products moot and renders the argument down to just one point, they are not needed in the first place. So why are the manufacturer’s selling all the unnecessary bio friendly media and, more to the point, why are we all buying it hook, line and sinker?

Jeff.
 
#35 ·
Interesting! I'm actually kind of surprised that the rates are so similar. Not because of a difference in the amount or ratio of surface area, but because I had guessed it was mostly related to the rate of reproduction in the bacteria (the larger quantity of ammonia would require more generations to build the population). Actually, that might still be true given that the 10 gallon took a little longer if they have a near exponential growth rate.

Anyways!

From what I understand, unless you start with a colony from another source, the bacteria that come to inhabit your tank are initially airborne in small numbers and settle into your tank to eat and reproduce.
 
#36 ·
In the air model the timelines would depend on surface area for the introduction of the micro organisms which is not the case. My jar has a small top compared to the volume and it was very fast... 7 days to completion.

I just got off the phone with a water treatment tech... I was curious and thought I might as well ask someone who knows this stuff.... here;'s a couple of interesting points from the conversation:

They don't add anything to start their cycling in large scale ponds.... thousands of gallons here.

Everything is already in the water (not the air) and once they add "dirty water" the cycle takes... get this.... 7 days to establish.

My scalability assumption form tank to tank was right, I didn't think it would scale to that size as well.

They can cycle the same bacteria from aerobic to anaerobic depending on water circulation and oxygen injection.

The tech happens to have a 170 gallon aquarium at home... cool... and a 72 that he just sent me a picture of that had the front glass let go on him after Christmas... not so cool.

Jeff.
 
#37 ·
I'm not sure how you infer that the "in the air" model is wrong or, at least, less apropos than the "in the water" model. Your tech-friend's pond is exposed to atmosphere and is probably not using chlorinated tapwater; water which, I must assume barring evidence to the contrary, contains little bacteria of any kind...at least that's the theory behind water treatment.
 
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