"the theory of the cycle"

[melbournefl]

I've been thinking lately about the whole "cycling" concept and have some, possibly retorical," questions. First let me say that I think I understand the concept but ...
Okay, the general concensus here is that using a raw shrimp to start the cycle is probably the *right* way to go. So, I have 250 gallons of salt to work with, I toss a shrimp in, cycle begins, bacteria multiply to take care of the bioload, life is good. Mr. X has a 10 gallon nano, he tosses in a shrimp, cycle begins, bacteria multiply, life is good. My confusion is regarding the bioload, given the same size shrimp is used in both cases wouldn't the bacteria that develop be capable of handling roughly the same bioload?
If this is the case, and I want to start with say 4 or 5 fish when my cycle is complete (I know that's too many, remember I'm talking theory here) then wouldn't I be better off to toss in say 15 shrimp in the 250 tank? Wouldn't the bacteria develop to handle the increased bioload and be capable of handling a higher bioload when the cycle was complete?
Again, this is just theory and something I've been wondering about.
Thanks to all who care to dive in here (pun intended)!
Later,
Paul

 

[cap'n pete]

The thought process is this, or at least as I understand it. By starting a cycle, all the necessary bacteria are introduced into the system. Once established they can multiply very rapidly to compensate for additional bioload. If bioload is added slowly enough you should see no noticable minicycles as the bacteria "catch up" so to speak. In a 250G tank I would add perhaps three shrimp, no more. The reason is this. You want to have adequate bacteria to maintain a healthy system, not one that has things consistantly rotting in it. One shrimp left to decompose is probably close to the organic load of 4 or 5 medium sized fish, if not more. I would add 4 to 5 fish once the cycle is complete and then add specimens one at a time thereafter. By adding shrimp we are not really trying to match bioload, we are trying to get a cycle to start and complete.

 

[jbeck]

Another question along these lines. IF setting up a new tank with live rock in it, should you still put a shrimp in or is there enough die off/bacteria already on the rock to get the cycle going?

 

[broomer5]

ahhhh .. a rhetorical question ~ my favorite ~ one that normally does not have a clear answer
As I see it - part of the question centers around this:
One guy tosses 1 shrimp into a 10 gallon tank of saltwater with sandbed/substrate.
Another guy tosses 1 equal sized shrimp into a swimming pool of saltwater with sandbed/substrate.
Which tank will have more mature/established population of bacteria AND which tank would be better suited to accept the first introduced fish ???
Heck I don't know , but I have an opinion.
Bacteria grow in a response to several factors - one of them being a food source. In our cycling tank question - that food source will be ammonia and nitrite.
Each food source ( and other factors ) fueling the reproducing bacteria. One leads to the other until the numbers read zero ~ right ?
Bacteria will continue to grow until the fuel souce is depleted - then some will live and continue to reproduce, while other's die off. They're bacteria - but they still have a life cycle.
So the next quesiton is this:
Is every square inch of the tank surfaces AND every particle of sand in the substrate completely covered with these growing bacteria ???
Heck I don't know , but I have an opinion.
I would image that the degree to which the tank's surfaces are colonized by bacteria is again - in response to the fuel that feeds them. In other words - given the same water conditions - our little 10 gallon tank would have more of it's surfaces covered in living reproducing bacteria, than our swimming pool sized tank's surfaces would have.
Grab a cubic inch of substrate from each tank - theoretically count the bacteria in each cubic inch of sandgrains.
Which cubic inch of sand would have the most bacteria ?
Heck I don't know , but I have an opinion.
I'd say the 10 gallon tank's substrate would have more bacteria per cubic inch of sand - and thus would have a more "efficient" biological filtering capacity than that of the very large swimming pool tank.
So the next question that comes to mind ~ how many shrimp does it take to initiate the nitrogen cycle, and how much ammonia is "optimal" for a cycling tank to get off on the best start ?
I don't know ?
Probably a level in mg/L ammonia that is sufficient enough to get the ball rolling ~ but not so high that it takes forever to cycle the tank.
This sounds like a question for the bacteria~ microbiology guys out there.

 

[jbeck]

Also if I DO throw a live shrimp in a new tank along with LR, will the ammonia spike from the shrimp kill off some of the good things in the LR?

 

[melbournefl]

LOL Broomer *all* that for an "I don't know" ????? OMG man you're slacking off again! Okay all you microbiology majors out there, jump in, inquisitive minds want to know.
Later,
Paul

 

[broomer5]

Yeah - slackin off again !
Seems to me it's a simple but very complex scenerio.
Any population of living organism will grow and reproduce based upon it's food.
Limit the food - limit the population.
Limit the food - and those that do live will reach a point of balance. The weak die off - the strong survive.
Too much food - faster than can be consumed by the growing colony - and it goes to waste, or more like the excess just floats around in the tankwater until it can be converted/consumed.
Until the numbers increase to consume the excess - the rate of growth will continue at somewhat of a logarithmic to the base 2 rate.
1 become 2, 2 becomes 4, 4 becomes 8, 8 becomes 16 .......... and so on. Population of these bacteria will double over a certain amount of time. Bacteria "split" to form new ones - they don't have a litter of little nitrosomonas or nitrobacter pups.
How fast the population doubles in numbers - depends on a lot of things for sure.
Water temperature, oxygen supply, other elements necessary for growth, health of the population, competition for these resources and of course - the food supply.
I still don't know for sure about any of this - just replying to your thread

 

[melbournefl]

Okay Broomer, I'll agree with all that but .... the original question still remains .... I'm getting ready to cycle 250 gallons of water, by putting more raw shrimp in, do I compensate for a higher initial bioload of fish when I first stock my tank? Providing, of course, that I am monitoring the water constantly and immediately on completion of the cycle put in this hypothetical boatload of fish so the bacteria do not begin their "starvation die-off."
Thanks again,
Paul

 

[broncofish]

I took a microbiology class where the professor actually used a a fish tank cycling as an example(he kept cichlids). Anyway basically he was talking about bacteria growth rate. If you have good water flow at the bottom of your tank the bacteria will spread quickly...and I'll bet if you did a poll of people who's tanks cycle in 3 weeks or less you would find that all of them had at least 2 or 3 power heads and at least 1 of those powerheads was aimed slightly down at the sandbed. Of course if the food source is not there that will greatly slow down or halt your growth rate also, But I am definitely no expert, heck I am a computer engineering major.

 

[broomer5]

the original question still remains
do I compensate for a higher initial bioload of fish when I first stock my tank?
I would say yes.
Opinion time again.
Ideally - you would want to watch the test results and follow the curves of the ammonia and nitrite - right ?
If you add a couple of small raw shirmp - let them rot a day or two - and monitor the ammonia/ammonium until it get's to a certain level ~ say 3-4 mg/L - then you should have bacteria beginning to grow.
Keep monitoring the progress - and as this level falls - toss in some more bits of shrimp ( say 1/2 of a shrimp cut up ) Ammonia spikes back up right.
You're feeding the existing population again.
I would call this a "hard" cycle. You're forcing A LOT of ammonia into the tankwater - causing the bacteria to grow - then to play catch up - then feeding more ammonia.
How long would you do this for ?
Until you see the ammonia fall and stay low - even after adding the same 1/2 shrimp bits ( ammonia ).
Eventually you'll have enough bacteria to handle any new additions of new bits of shrimp. You'd be prolonging the cycle - but at the same time - you'd be insuring that you've maxed out the bacteria growth. One controls the other.
Eventually though - as you placed more ammonia in the system - this huge colony of established bacteria in the sand/filter media would consume the ammonia fast. Fast enough to drop it down to near zero. It all depends on the "controlled" amount of shrimp bits you add.
Once the system is allowed to reach zero ammonia - even if you prolonged the cycle - then the nitrite converting bacteria would begin multiplying as they should. Eventually - the nitrites would drop to zero and you'd consider the tank's biofiltration to be cycled.
The other way to look at it is to do a "soft" cycle.
You toss in however many shrimp you "think" will do the job ~ let the ammonia spike and fall, let the nitrite spike and fall ~ and presume that the biological filtration is adaquate.
But you'll never know - until you add a fish.
If the ammonia stays at zero - then your bacteria colony is big enough to handle the added ammonia. If ammonia registers on the kit - not enough bacteria - and you gotta wait for the system to play catch up again.
This induces a huge risk on the fish - especially at high pH.
Cycle the tank hard.
Force it to grow a lot of bacteria - by not rushing - and by feeding it ammonia in the form of more bits of shrimp.
Monitor the tankwater with test kits.
When you see the test nearing zero - you know for sure that you've done everything you can to allow the largest population of bacteria to flourish.
Or - just toss in 5-6 raw shrimp like many folks do - and just let it do it's thing with little intervention on your part.

 

[melbournefl]

OH heck nevermind, mute point now. My boychildmonsterfromhell (15) just came home with his hair permed and wanting a tatoo so I've decided to toss him in the tank and be done with it! If that doesn't prepare the tank for a huge bioload nothing will. But it was an interesting discussion, thanks all.
Later,
Paul (soon to be the only inmate with a 220 gallon tank in his cell)

 

[dindi]

Then there is nitrate...does it all stop there? What is after that? Dump the water and do new? Help is needed with this one I think.

 

[overanalyzer]

I think that in some ways this is more philosophical than microbiology. This relates to relativism. The relative mass of the initial bioload introduced (raw shrimp) V. the area of population for bacteria (tank size).
Using the initial example we know the logic is faulty:
if 1 shrimp will ideally cycle and 10 gallon tank
then 1 shrimp will ideally cycle a 250 gallon tank
therefore you only need 1 shrimp to cycle a tank from 10 to 250 gallons.
Faulty logic as 1 shrimp will always equal 1 shrimp but 10 gallons will never equal 250 gallons. Therefore the assumption is false. (Long live the Vulcans)
SO how many shrimp would we need. Lets apply some logic again:
IFF (if and only if) 1 shrimp is needed to cycle 10 gallons then X shrimp would cycle 250 gallons. Therefore 1:10::X:250 - therefore (using cross multiplication 1/10=X/250) X=25 shrimp. Thus the logical conclusion is:
IFF 1 Shrimp is the desired amount for the best cycle of a 10 gallon tank
THEN 25 Shrimp would be the desired amount for the best cycle of a 250 gallon tank.
Of course fault tolerances and biological effects are not factored in (fault tolerances = differing decay rates and shrimp size) and Biological effect = the growth rate of the desireable bacteria.
What we would need then is to know the growth rate and size specifics. WE could then logically prove that IFF 1 shrimp is the best way to cycle a 10 gallon the N Shrimp (Being the number X factored against growth rate) would be the ideal amount of shrimp to cycle a 250 gallon tank.
Needless to say I did not do well in microbiology (though I loved chemistry). Ahhh I miss logic discussions.
Well not much of an answer but it made me forget for a while that I work with a huge parcel of illogical cretins .....
Thanks!

 

[broncofish]

Originally posted by overanalyzer
Faulty logic as 1 shrimp will always equal 1 shrimp but 10 gallons will never equal 250 gallons. Therefore the assumption is false. (Long live the Vulcans)
/B]
The Man has a masters degree but types things like that. Makes you wonder about the Kansas education system.

 

[overanalyzer]

Dindi - sorry - you may want to post a new topic since this has gone pretty far afield ....

 

[leboeuf]

what about the die off from the LR ? There is no way to measure lbs of LR verses dead shrimp....... The only thing I really understand from this discussion is to constantly measure ammonia? right?

 

[overanalyzer]

LeBeouf - yes - you should always monitor the big three when watching the cycle:
Ammonia
Nitrates
Nitrites
I think the discussion was how to figure out how much initial bioload to add ....
As you can see it got somewhat out there .... I think Sammy's is the most practical post from length (or lack of) and succinct information.

 

[pmauro]

let me throw this out there I am cycling my 450. I threw in 8 3-4 inch dead shrimp 4 days ago and my amonia lelel is still 0 is 8 enough for 450 gallons

 

[bang guy]

Yep, that's plenty... wait another week.