Is this even a debate? Most of the nitrifying bacteria is not in the canister filter, it is in the soil and hardscape.

[rob_dixon]

Forgive me but i am new (2 years in to the hobby) but this is either undisputed already, or I have a scientific anomaly.  I have twice tried to “hack” a faster cycling on my main tank by running a filter on another side tank for many weeks before I put it on my main one (thinking how smart I was of course - a head start while i do a dry start I thought!)

The fact that the side tank was cycled was verified through testing of course - ammonia added brought down to zero.   But once I moved that very same “cycled” canister filter to my new tank 3.5 weeks later, the new tank was no longer cycled.  NOT IN THE SLIGHTEST.    I am now 13 days on my main tank with a filter that was supposedly cycled for 3.5 weeks prior but its like the cycle started all over again and I am again in waiting mode.

The thing is, this is the second time I have experienced this - i did the same thing on another "main tank"  (I run two main tanks and have a third tank out of sight.  This leads me to believe that the media in the filter is not at all where the bacteria reside, but primarily on the inside of the tank.  This also points out how much time, money, and energy is wasted on canister filters IMO which are apparently super overrated.

Edited November 2, 2023 by rob_dixon

[rob_dixon]

It's a huge ADA superjet 900 running all biomedia.  I too am used to running only sponge as I know it's superior, but in this case the filter came with the biomedia included.

I actually Not only let it cycle naturally (although added ammonia) but I also seeded it by squeezing out my sponge from my other tank into the intake of this canister filter. AND adding grass from my established tank.  That is what makes the situation even more perplexing!

[Guppysnail]

This video explains towards the middle how media in filters is seeded and what you may be experiencing 

Moving media from existing filters works for me every time for decades.

No matter how big a filter is you only have as much bacteria as you have bioload. 

[lefty o]

the bacteria is on every surface in the tank, including in the filter, but here's the kicker there is a set amount based on how much waste there is for the bacteria to feed on. if there isnt enough waste for the bacteria to feed on it dies off to a level where there is sufficient waste for it to feed on. where the bulk of the waste is, is where the majority of the bacteria will be found. so you will likely find the substrate has a good portion of the bacteria, inside a canister, or hob will likely be next in line, then everything else will have some. bacteria multiplies very fast, so if you want more bacteria, lightly over feed.

[rob_dixon]

Nice, This is totally what it is then!   Fantastically explained, and in hindsight super obvious.

I used a ginormous filter on a tiny 14 gallon tank.  It was "cycled" but only to that tiny amount i was putting into that tank.

When i moved it over to the new 48 gallon tank (even though there was no FISH) it was indeed new aquasoil with lots, lots more ammonia.   HENCE, just like you guys (and Cory's video) said, it simply did not have enough bacteria inside and is basically not cycled.

Thanks so much guys!

[Odd Duck]

Came here to say all these things and everyone beat me to it.  Your tank / filter will cycle to your bioload.  If the bacteria was only in substrate and on hardscape then bare bottom tanks with no hardscape are in deep trouble.  But they aren’t actually if they have a good level of biofiltration. I have 3 bare bottom, no hardscape, 5 gallon guppy tanks that are loaded with guppies.  Well, 2 are loaded, one isn’t quite yet.  I moved at least 25-30 out of one today (because let’s face it, I’m playing with fire at this point, they are only 5G) and it was not quite half the total population.  I really need to take some to my LFS!  But I have medium ACO sponges in them because they were intended as “dirty” snail, scud, blackworm tanks for pea puffers.  Then they got some mosquito larvae, so I popped a male guppy in each.  Then other guppy tanks got crowded so more guppies went in, and now I need to thin the herd.  Or is it horde?

My point is, that the tank population grew gradually, so food gradually increased, and beneficial bacteria population grew along with the guppy population.  You had so much overfiltration that your bacteria weren’t stimulated enough to grow a decent population in your giant filter.

[nabokovfan87]

I would argue that the tank has a few types of bacteria, not just one. We know of the big two that are involved in the nitrogen cycle. .

Basically, in my view the key is that the strongest bacteria will be where you have certain conditions, namely oxygenation and circulation.

On 11/2/2023 at 12:38 PM, rob_dixon said:

The fact that the side tank was cycled was verified through testing of course - ammonia added brought down to zero.   But once I moved that very same “cycled” canister filter to my new tank 3.5 weeks later, the new tank was no longer cycled.  NOT IN THE SLIGHTEST.    I am now 13 days on my main tank with a filter that was supposedly cycled for 3.5 weeks prior but its like the cycle started all over again and I am again in waiting mode.

I've had similar things happen and it all has to do with a few factors for me.

1. What surface is the bacteria on.

2. How strong is it (how quickly can it grow)

3. Did anything happen to cause it to die off. Did the bacteria lose its food source?

[nabokovfan87]

Here's a pretty cool breakdown of how they function, grow, move, etc.

https://www.engineering.iastate.edu/~jea/w3-articles/nitrifier-physiology/nitrifier-behavior.html

 

Edit:

Here's one study on different media surfaces and how well they handle strong bacteria growth.

https://scialert.net/fulltext/?doi=jas.2010.1146.1150

Similar study with a control, bioballs, and borings

https://www.google.com/url?q=https://iopscience.iop.org/article/10.1088/1755-1315/441/1/012121/pdf&sa=U&ved=2ahUKEwih8JHj8KaCAxW_NkQIHZqVAXQ4ChAWegQIBRAC&usg=AOvVaw3vNVX76SbLuUj6CWyEef-s

 

There is another with sponge testing compared to others, not easy to find. I'll keep looking.

Edited November 3, 2023 by nabokovfan87