Cycle

daveedka wrote:

"Yes water changes slow the cycle time,..."

Sorry, but this is another of those misconceptions mentioned. So long as there is unoxidized ammonia or nitrite in the tank water, even below that detectable by hobby kits, the ammonia-oxidizing or nitrite-oxidizing bacteria will be at maximum growth rate. Reducing the titer of either to or just below minimum detectable levels will not slow the multiplication of the bacteria at all. These are slow-growing/multiplying bacteria, it is easy to saturate the system.

What will be affected is the total end colony size. Fishless cycling aims at a colony size capable of oxidizing ~2.5ppm ammonia through to nitrate within less than 24 hours. That is a comfortable margin of safety past any reasonable stocking level, even with overfeeding.

Cycling with fish, and maintaining lower titers to protect the fish from injury, will minimize the colony size to the bioload present at the moment, period.

Key difference. If I have not explained it well enough, let me know and I'll try again.
 
RTR,
I understand what you are saying to some extent, but still have a quetion.
On the gronds that bacteria like many things will reproduce to consume the available food source:
If the loweing of titers does not slow the cycle to some extent, what is the need or reason for going up to 5 ppm ammonia on a fishless. My observation ( with a lot of variables) was that my fishless ran faster than my fishy cycles. If I understood you correctly, It would make more sense to start a fishless cycle at 1ppm and increase the titer towards the end of the cycle rather than the opposite.

I do know that water changes won't hurt or stall a cycle but also have believed that reducing levels to undetectable seemed to add 7-10 days to completion. As always, I'm trying to learn what I have yet to know.
 
Ammonia and nitrite are to nitrification bacteria what carbs are to people (or were prior to no-carb diets). They are energy source rather than biomass building blocks. The uptake/oxidation process saturates more than an order of magnitude below the lowest detectable inexpensive hobby test level. These bacteria are among the slowest-growing I have ever worked with - the population doubling time is comparable to most mammalian cell culture more than to the average bacterial cell culture.

The titer does control the terminal colony size. The biomass of either/both species must be much larger to oxidize 3ppm ammonia than to oxidize 1ppm ammonia or 0.1ppm ammonia. That should be self-evident, each component cell can intake and oxidize only a small and defineable quantity of reduced nitrogen metabolite. This is where the difference in fish and fishless hits. With fishless, you can provide/develop sufficient nitrification bacteria biomass to fully oxidize metabolites from even what will be an overcrowded tank prior to the introduction of fish. That is done by higher titer of the metabolites - with fish, that would involve gill damage or suffocation to operate at those levels, so the colonies slow down their division - there may not always be surplus metabolite for them to grab- the total colony size is restricted. If your tank is optimized for biofitration (IME Canisters w/bioballs or FBF) that restriction is less likely to occur as those techniqes allow maximum colony exposure to metabolite and oxygen, plus the minerals, etc required for real tissue building. But you cannot say that the technique requires optimum biofilter conditions - that was a non-trivial requirement for the technique. Novices (or anyone else) should be able to use any form of commercially available filter (or their DIY versions) and still get the same results, plus or minus a few days.

In theory, the most efficient process for the bacteria would follow the step-wise increments in metabolites that you suggest. In practice that takes longer as our tests are not that good. To optimize that process you would be best operating with probe sensors and auto-dosers to maintain optimum titers - not at all a hobby technique. Otherwise you get surplus and deficit periods - never optimum. It is "better" (more practical) to somewhat overdose but be below potential toxicity than to risk slowing down an already slow bacterium.

Before Chris' technique for novice fishless cycling, there was a significant amount of argument (with some basis in fact as seen from experiment) that the nitrite oxidizers should be established first, then the ammonia oxidizers. That is never going to be a novice technique, as it requires lab grade chemicals, microgram balances, and laboratory analysis equipment to run. Chris' aim was a simple process that anyone with a small selection of kits could do at home.

The drawbacks to Chris' technique are 1) that getting clear ammonia (nothing but ammonia in water, possibly with a chelator) is no small thing in additive-happy America - additives provide definable branding, all-important to corporate niche-guarding. 2) that the technique is not suited to low-alkalinity water without extra care and testing. The first issue we were aware of before we started popularizing the technique. None of us in the game early had low-alkalinity water or thought to test under those conditions, so that one got by us until it appeared on the boards and became obvious. Overdoses we knew were damaging (slow the process), but low pH/KH damage we missed in early tests. And 3) that the initial introduction of bacteria is important. This is the primary controller of total cycle time. Chris suggested that novices with no access to established filters use rock-wool potted plants, preferably fresh to the LFS. Those plants are largely done hydroponically, the pots submerged in circulating nutrient solutions, the plants (cuttings or divisions) emerse in high-humidity or fogged air. Those rockwool plugs develop plenty of nitrification bacteria during plant development and serve as tank innocula. But that caused a whole world of confusion - nobody got the point that the plant did not matter - it was the rock wool that mattered, and that it had not been away from its circulating hydroponics too long. The blow-back from that has still not ended. Mass confusion. Without a sizeable bacterial introduction, the nitrite oxidizers can starve and die before enough ammonia is oxidized to nitrite to feed them. So, both items #2 & 3 can result in extended nitrite oxidizer development if there was no or too small bacterial numbers put in initially. That is not so big a deal -correct the KH/ph by bicarb or introduce more bacteria - but that seems hard to get across on the boards for some reason. I have all but quit tring to help fishless cycle posts, as you can ask multiple times and never get responses on pH and KH, or if or what startup technique was used. If anything I just cite Chris' third article and let it go.
 
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Thanks RTR,
I think I got it. Things just weren't adding up in my mind despite what my observations were telling me. I did get the part about the plant wool (one of your posts to someone) back when I was doing my cycle. and that is what I used to seed my first fishless. I pulled the plants out and planted them (slight mistake) and then bagged the wool from the pots and dropped it in my filter. other than the algea from 5ppm ammonia, plants and lights ( I learned the error of my ways after the fact) The cylce worked quite well.
 
Whew, good - IMHO, understanding aquarium processes is key to being able to trouble-shoot them. This is especially true when several different causes can give the same visible result - such as an extended nitrite "spike".
 
IMHO, understanding aquarium processes is key to being able to trouble-shoot them. This is especially true when several different causes can give the same visible result - such as an extended nitrite "spike".
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In my profession, just as with scientific experiments understanding all of the variables is the key to finding the correct answer. This is something I find easy to apply when I know what the variables are or might be, but something that doesn't come naturally to most people. I try very hard to seperate and control variables, thus my observations can be more accurate. At the same time I discard any observation that has too many uncontrollables, or unknowns.
As I tell my students, simplify every process to the lowest common denominator, and when you understand how each step is supposed to work, then you can determine which step didn't work and find a cause. Sounds simple, but of course it isn't at all or I would already know everything :D :D :D
 
No, not really any hope of that clarity - none of us has any hope of knowing everything, but with a bit of methodology we do have hope of learning some things which help us trouble shoot issues.
 
Originally posted by Richer
Very rarely doesn't mean no fish die. I have never lost a fish in a fishless cycle... because no fish are involved.

Lets break it down a bit:

Cycling with fish:
What does it involve? Sticking a few hardy fish into a tank, and letting the ammonia the fish naturally (and decaying fish food) produce start up the cycle.

Pros:
-You have fish in the tank right from the beginning.
-The tank will cycle successfully.

Cons:
-The fish have to swim in water containing detectable levels of ammonia/nitrite. This leads to the possibility that the fish may contract diseases, infections, etc. because their immune systems may take a hit from the ammonia/nitrite. Exposure to ammonia/nitrite may also reduce fish lifespan.
-The constant water changing that is necessary to reduce ammonia/nitrite levels to a less toxic level, so that your cycling fish can survive.
-The fish you use must be hardy fish so that they can survive the cycle. What will happen if those fish aren't part of your stocking plan? Will you return them? What if the fishstore will not accept them?
-Even a complete cycle isn't complete. Fish have to be introduced slowly to the tank. Introducing too many fish at once will upset the balance of the tank. Remember that the tank only has enough bacterial colonies to convert the waste of a few fish, not a full load of fish.

Fishless Cycle:
What does it involve? Buying ammonia from a store, adding this ammonia to a tank till you get an ammonia level of about 5ppm. The ammonia added will start the cycle.

Pros:
-Spares fish from swimming in water containing detectable levels of ammonia/nitrite. Which prevents any of the ammonia/nitrite related problems a fish may get.
-Cycling a tank on 5ppm of ammonia will give the aquarist a large margin of error for fish stocking. Unless a person really packs a tank, fish will never produce enough ammonia to get an ammonia reading of 5ppm. In turn, this allows the aquarist to fully stock a tank after a successful cycle.
-A few people have said that fishless cycling actually speed up how quickly a tank will cycle.
-Like a fish cycle, it will cycle a tank successfully.

Cons:
-One very large water change at the end of the cycle is needed, to remove the large levels of nitrates that are probably in the water. Still... not as bad as doing multiple water changes during a fish cycle.
-You will have to look at an empty tank for 2-3 weeks.


Seems to me that a fishless cycle is the clear winner. I probably missed some stuff, but that is the general gist of it.

HTH
-Richer
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Richer,

OUSTANDING POST ! ! !

I copied this and printed it out.
 
Originally posted by JSchmidt
Great post, Richer. I'd add to the cons of fishy cycling that fish cycling may cause permanent damage to sensitive gill tissue from ammonia burns, and the discomfort the fish feel from swimming in toxins.

There are certainly greater evils in the world than cycling with fish, and some folks who practice fishy cycling are no doubt extremely conscientious to minimize damage/discomfort to the fish. Newbies are much more likely to err during cycling, though, and expose fish to dangerous level of toxins. Even worse, the idea of using 'cycling fish" seems to promote the idea that some fish are more or less disposable, an idea I find in opposition to the feelings that make me want to keep these creatures as pets.

Jim
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Well put Jim.

Me being a newbie, started my tank as a fishy cycle, but when I saw the effects of the Ammonia on the fish (they acted very strange after awhile, and showed great signs of stress like hiding in the caves I made in the tank) I had to remove them from the tank.

I 'd rather watch a happy fish then watch a fish suffer. They are now doing great in my 10 GAL for now. They will soon be in my pond I am gonna build in my back yard :D
 
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