A question about fishless cycle and live cycle?

[maff2026]

I've been reading quite a bit about the arguments of both ways but I have a fundamental question if I may which I'll pose as an hypothetical.
Jim has been raising marine fish in his 200 gallon tank for 10 years and in that marine tank is a huge amount of live rock.
Jim wants to set up a small tank in his house but only 50 gallon and he's pondering whether to go fishless or live.
Jim works out that he can breed a fishless colony of bacteria with the following numbers: 1.5 billion ammonia and 3.5 billion nitrite bacteria. he works out that a single small clown will be quite happy with this colony and expects a bacteria dieback of some 65% which is a good number.
Jim then works out that a 5lb rock from his main tank has 1.8 billion ammonia and 3.9 billion nitrite bacteria and estimates it is sufficient for a single clown fish with an estimated bacteria dieback of 70% which is also a good number.
My question is, why would Jim think it wrong to do a live cycle when he is providing more bacteria than the fishless cycle and on paper in both cases you will get associated dieback of bacteria?

 

[JumboShrimp]

I found this interesting, as general knowledge.

 

[Freenow54]

I've been reading quite a bit about the arguments of both ways but I have a fundamental question if I may which I'll pose as an hypothetical.
Jim has been raising marine fish in his 200 gallon tank for 10 years and in that marine tank is a huge amount of live rock.
Jim wants to set up a small tank in his house but only 50 gallon and he's pondering whether to go fishless or live.
Jim works out that he can breed a fishless colony of bacteria with the following numbers: 1.5 billion ammonia and 3.5 billion nitrite bacteria. he works out that a single small clown will be quite happy with this colony and expects a bacteria dieback of some 65% which is a good number.
Jim then works out that a 5lb rock from his main tank has 1.8 billion ammonia and 3.9 billion nitrite bacteria and estimates it is sufficient for a single clown fish with an estimated bacteria dieback of 70% which is also a good number.
My question is, why would Jim think it wrong to do a live cycle when he is providing more bacteria than the fishless cycle and on paper in both cases you will get associated dieback of bacteria?

I dont know how " Jim " got a Dieback number whatever that is please elaborate. as to the actual rock as to lore " Jim needs 50 pounds . If " Jim " can spare that then he has a green light . I have no idea how long a mixture will cure . Interesting question to me , but have no idea and why worry . Just mix the rock do the check by adding 4 ppm of PURE ammonia and see what level its at the next day. Then : Jim can put his scientific calculator away

 

[Freenow54]

If at zero

 

[maff2026]

I dont know how " Jim " got a Dieback number whatever that is please elaborate. as to the actual rock as to lore " Jim needs 50 pounds . If " Jim " can spare that then he has a green light . I have no idea how long a mixture will cure . Interesting question to me , but have no idea and why worry . Just mix the rock do the check by adding 4 ppm of PURE ammonia and see what level its at the next day. Then : Jim can put his scientific calculator away

If Jim has a huge bacteria colony in his main 200 gallon tank because it is well stocked with many healthy fish and he transfers a large rock into his 50 gallon tank as a seed to start a new colony in the new tank, a small fish may not provide enough ammonia to keep the entire colony alive. Therefore there would be dieback of the colony to the amount of available ammonia.
Now if you do the same with a fishless cycle and produce a large colony of bacteria and again, the fish cannot provide enough ammonia to keep the entire colony alive, there would be dieback of the colony to fit the available ammonia. My question was what is the difference if you transfer the colony from another tank or you grow your own, to the fish itself what is the primary difference?

 

[KrisReef]

Liverock with bacteria present is already cycled and the fish is prevented from ammonia exposure by the bacteria population that is present.

You need to start with dry, microb- scarce rocks if you want the fish to experience the ammonia build up before the “cycle” occurs.

 

[Freenow54]

Liverock with bacteria present is already cycled and the fish is prevented from ammonia exposure by the bacteria population that is present.

You need to start with dry, microb- scarce rocks if you want the fish to experience the ammonia build up before the “cycle” occurs.

Sorry you lost me on the second part could you please elaborate ?

 

[KrisReef]

Sorry you lost me on the second part could you please elaborate ?

If a person wants to use a fish to cycle they need to start with dry rock, otherwise using live rock there is not a cycle (ammonia rising and then the bacteria grow).

 

[maff2026]

The reason i'm asking this hypothetical is because there are conflicting ideas about cycling. Now in the past, I've always live cycled freshwater tropical with a transfer of live media from a cannister filter into another. That means a large portion of filter sponge and ceramic noodles from one cannister to another. Then I've slowly added very small fish over a course of a few months keeping up with daily checks of ammonia, nitrite and nitrates. in all honesty I've never spiked a tank in 40 years.
My local fish shop is suggesting a couple of small fish and a largish live rock and he is an award winning shop. meanwhile everyone on youtube is saying its barbaric but i don't understand their logic. If home grown bacteria is capable of sustaining fish but also liverock is capable of sustaining fish where is the argument?

 

[Freenow54]

The reason i'm asking this hypothetical is because there are conflicting ideas about cycling. Now in the past, I've always live cycled freshwater tropical with a transfer of live media from a cannister filter into another. That means a large portion of filter sponge and ceramic noodles from one cannister to another. Then I've slowly added very small fish over a course of a few months keeping up with daily checks of ammonia, nitrite and nitrates. in all honesty I've never spiked a tank in 40 years.
My local fish shop is suggesting a couple of small fish and a largish live rock and he is an award winning shop. meanwhile everyone on youtube is saying its barbaric but i don't understand their logic. If home grown bacteria is capable of sustaining fish but also liverock is capable of sustaining fish where is the argument?

I used a fishless cycle . In the past the fish was considered sacrificial . I am not arguing just know what I do.

 

[maff2026]

I used a fishless cycle . In the past the fish was considered sacrificial . I am not arguing just know what I do.

But couldn't you just add a liverock, test the liverock with an amount of ammonia then add fish once you establish its working good?

 

[KrisReef]

The reason i'm asking this hypothetical is because there are conflicting ideas about cycling. Now in the past, I've always live cycled freshwater tropical with a transfer of live media from a cannister filter into another. That means a large portion of filter sponge and ceramic noodles from one cannister to another. Then I've slowly added very small fish over a course of a few months keeping up with daily checks of ammonia, nitrite and nitrates. in all honesty I've never spiked a tank in 40 years.
My local fish shop is suggesting a couple of small fish and a largish live rock and he is an award winning shop. meanwhile everyone on youtube is saying its barbaric but i don't understand their logic. If home grown bacteria is capable of sustaining fish but also liverock is capable of sustaining fish where is the argument?

Your lfs is up to speed on marine cycling.

Another interesting fact is that nitrITe is not toxic to fish in marine environments at typical cycle concentrations. Therefore, there is no need to monitor NO2 levels in marine tanks. Freshwater, nitrite is a potential hazard.

Edit
Especially for cycling purposes. Nitrite confounds nitrate measurements and so people who are monitoring nitrate in a marine environment need to be able to measure the difference, maybe.

 

[maff2026]

I used a fishless cycle . In the past the fish was considered sacrificial . I am not arguing just know what I do.

With a fishless cycle, how did you determine how much fish stock you could put in without an ammonia spike?

 

[Fish Fan]

I would tell Jim to not over think this

"Cycling" typically refers to the initial nitrogen cycle when you first start a tank. This process will happen in about 3 to 4 weeks without you doing much of anything at all, even if you start from all dead/dry rocks and sand, you simply can't stop it if you tried.

You cycle rock and sand and filter media, not a tank; the microbes don't exist in the water, typically. When you use rock or sand or filter media from an existing tank, you're using "pre-cycled media", and you are therefore skipping the the majority or all of the "initial nitrogen cycle"

How many bacteria or how much surface area you need for each pound of Clownfish per gallon of water has likely been quantified by people much smarter than I am, like my friend @KrisReef, who's bound contractually to keep such info hidden to us regular folk, but I don't know what that ratio is, and I can think of only about three people on this forum that could take a legit stab at that estimation; don't over think this, again

The value in starting with pre-cycled media (rock, sand, bio media) from an existing system is that the bacteria are well established, and therefore quick to multiply and spread in response to additional real estate and ammonia.

Use mature "media" (rock, sand, bio media), stock slowly, add hardly livestock like motile inverts, Clownfish, etc., and I believe you'll be fine

Good luck!

 

[Freenow54]

With a fishless cycle, how did you determine how much fish stock you could put in without an ammonia spike?

No Calculation . That would be subjective on a lot of factors . The volume of the tank for hiding and swimming are my only concerns . Just not overcrowding or too many , or fish that need space . You have to figure out how Large certain fish will get.