Wy Renegade
Aquarium Advice Addict
Sorry, i might have spoken off my a** ... after thinking twice, i don't know. I imagine cured, because it was sitting in the LFS i bought it from, and did not seem to have dead organisms on it, but how could i tell cured vs. uncured?
If i follow your logic, even the live sand could cycle a tank, correct?
Based on your experience, with cured LR or/and LS, how long one should wait to consider its tank cycled?
Also, how does that bring the anaerobic bacteria in the picture? Do you think they are already present in the cured LR?
So, you actually have several points of discussion here, and I'll do my best to address each individually.
First of all, lets start with the term liverock. Contrary to some people's opinion, the term liverock really only has one meaning in the aquarium industry, and that is that the rock contains bacteria, and that includes bacteria of all types (ammonia converting (Nitrosomanas as well as others), nitrite converting (nitrifying bacteria ~ such as Notrobacter, Nitrococcus, Nitrospina, and Nitrospira) and nitrate converting (denitrifying bacteria ~ such as Flobobacterium Pseudomanas, Vibrio, and Aeraomanas)). Some liverock will come with other organisms, some doesn't. Significant research has gone into proving that liverock does in fact contain all three types of bacteria ~ the first two types covering the surfaces and outer areas, and the third type deep within the anaerobic zone of the rock. Research has clearly shown that a balanced saltwater tank supported only with liverock can be successfully maintained long term. I can't think of the name of the method (named for the individual who initially proposed this method of aquarium keeping) but perhaps someone else will chime in. This individuals research is I believe still on going and well supported.
The term cured vs. uncured simply refers to the state of the liverock. Cured means that it has had time to sit in a stable tanks somewhere and decomposition of dead organic material from shipping has ended and the bacteria populations have stabilized. Uncured means the rock was recently shipped and dead organic matter from shipping is still breaking down (Exactly what we utilize when we "cycle" a tank). Most reputable LFS label their rock as cured or uncured.
In regards to your question on livesand, the answer is quite simply yes, and once again, this is fully supported by research. The initial method of maintaining a saltwater tank with real livesand (not the crap you buy in a sealed plastic bag), again the name evades me, involved a deep sandbed, and this individuals research is also fully supported and ongoing. Recent research also shows that both nitrification and denitrification can in fact be accomplished with a shallow sandbed, as anaerobic zones capable of introducing anaerobic bacteria are present even in shallow sandbeds.
In regards to the term "cycle" you've opened a entirely different can of worms. Cycle as it was traditionally used simply meant that all three types (or in most cases actually only two types ammonia converting and nitrifying bacteria) are present in sufficient amounts to support a population of fish. Now days it has become an almost magical term, which people are applying to a the notion that they need to build up bacteria levels of two or all three types to (so far as I can tell) a completely arbitrary level and that somehow magically this aquarium will thereafter support any chosen level of randomly introduced fish forever. Not true, bacteria levels in the aquarium are totally dynamic and fluctuate like any living population based on living space and food supply. So if "cycle" my tank the arbitrary level and then introduce only a single fish to the aquarium for a month, I've completely wasted my time in cycling the tank, since all the excess bacteria have died off, unless I am grossly overfeeding my single fish. Once bacteria levels establish to the population of the fish in the tank, and the feeding levels of said aquarium, the additional adding of bacteria (via bottled bacteria or otherwise) really adds nothing to the equation. The food and space in the aquarium supports X amount, adding more than that amount simply results in die-off of what you have added or some of your original population.
If you are adding fully cured LR to your aquarium from an established tank that already had a bioload to maintain bacteria populations, there is no need to cycle a tank period - all the needed bacteria are already present. That does not mean I can add an infinite amount of fish and other critters from the get go, as those bacteria levels do have to be built up to support the bioload. But if the bioload of the initial tank was already high, then the rock has sufficient bacteria to support a high bioload, at minimum, it will support a low bioload. Bacteria reproduce very quickly ~ most species will double their population in a matter of hours, so building up bacteria is no the months long process that some would have you believe.
In regards to your final question, yes they are already present in the LR. How do they survive in your bottles of bacteria, where oxygen has to be present to support the other two types of bacteria, since they don't survive in the presence of oxygen in an active form? Also bacteria colonies can be established from airborn spores ~ people have been doing that very thing for 100s of years with great success.