First Time Cycling With Existing Tank Water

[T1gger]

I wonder if you can help me. I want to speed up cycle time for new 50 litre tank.

I have 70 litre and 20 litre cycled tanks that I can take stuff from. Would you recommend water or stones or something else? Also how do you do this. The new tank has foam filters and both existing have section filters on top with charcoal etc. Ideally I want to buy a similar filter as I could steal filter charcoal and liner from existing tank as it will need replacing soon. Ive had the 70 litre tank cycled since May/June and the 20 since July/Aug and could steal a bit from each or all from 1. My 70 litre was treated with antibiotic and 20 litre never treated.

 

[Blondielovesfish]

Charcoal isn't really needed in a fish tank, it needs replacing about every month and can be a money waster. The most common use of it is to remove medication from the water.
 
The best thing to add to speed up your cycle would be some filter sponge or bio balls. You can safely take up to around 1/3 as long as you replace it afterwards. 
The other thing would be some gravel from either of your tanks. 

 

[Sophie]

You can safely take up to around 1/3 as long as you replace it afterwards. 

 
I saw TTA question this the other day - how can you guarantee the bacteria is evenly distributed over the media, enough to know you can safely remove a 1/3? You could be removing a bigger concentration of bacteria say for example, on the biomedia (ceramics etc) than there would be on a sponge or other type of media?

 

[daizeUK]

Old biomedia will benefit from being partially replaced at regular intervals (6-12 months) anyway, as fresh biomedia will offer greater surface area for existing bacteria to colonise.  Just keep an eye out for mini-cycles.

 

[Garbolino]

Instead of charcoal what would you recommend, as I run 2 fluval 306 external filters on separate tanks & I have biofoam on the bottom then the ceramic things then polishing pads with charcoal on the top

 

[the_lock_man]

I have never replaced my biomedia - I have ceramic tubes.

 

[Sophie]

I have never replaced my biomedia - I have ceramic tubes.

 
Same here, not even my bags of charcoal.

 

[KirkyArcher]

Instead of charcoal what would you recommend, as I run 2 fluval 306 external filters on separate tanks & I have biofoam on the bottom then the ceramic things then polishing pads with charcoal on the top

 
Despite lots of recommendations to put polishing pads in the top of your filter trays (including manufacturers instruction), I'd strongly suggest you try your polishing pads at the bottom just above the Bio foam in the same tray, Keeping all the mechanical filtration together (of which a polishing pad is effectively) that way very clean water flows over your bio media and so precious space and surface area is kept open for the bacteria instead of been clogged up with dirt.  Water alone from your other tank will not help with a cycle, 

 

[TwoTankAmin]

 
Old biomedia will benefit from being partially replaced at regular intervals (6-12 months) anyway, as fresh biomedia will offer greater surface area for existing bacteria to colonise.

 
I have never seen this said anywhere by anyone before, can you provide any scientific support for stating this?
 
All I can offer by way of contradiction is that is that I have some filters that have been running for 10 years or more without any bio media being changed or replaced. That would indicate the above statement is likely not accurate.
 
Or lets consider other factors involved. I run floss which I change weekly, another similar tank has no floss. Does the bio-media need to be changed in both at the same interval? Or lets take it another step. I have bare bottom tanks with rocks and wood. I know that the less filter media I have, the more bacteria is on the decor. As long as I have flow in the tank, I do not even need bacteria in the filter as it will be elsewhere in the system. So would I have to change the media in this bare bottom tank too?
 
Or lets talk about the oldest and still the most effective biological filtration system, the undergravel filter. I have used one. Are you now saying one should replace part of that gravel every 6 -12 months? What about the media in sump systems?
 
Unless the bio-media is "destroyed" or falling apart, all it needs is regular rinsing to keep it in decent working order as far as I can tell or have read.
 
Finally, here is another seemingly simple question that would appear to be the single most important consideration in terms of bio-filtration and which I can not answer and doubt anybody on this site can either. What amount of bacteria can colonize  nwhat volume of filter media. What are the volume/surface calculation for the media or for the bacteria? Or put another way, i can buy similar sized Poret foam sponges which differ only in their porosity. For example they offer:
4" Cubefilter
10 PPI blue
20 PPI black
30 PPI black
30 PPI blue
New:
45 PPI black
from http/www.swisstropicals.com/Poret%20Filter%20Foam%20Pricelist.html
 
Can you tell exactly how much more or less bacteria each one holds? Would each of these need to be replaced how often and why? In identical tank applications exactly what would the difference in clogging time be and why?
 
And finally, is there any reasonable evidence that shows that where the bacteria colonize the media is fairly an even distribution for the total area available to do so? Are more bacteria living near the surface or the center of the media? Are there more bacteria near where the water enters the media or where it exits the media? Does the media clog evenly so that you are assured of removing the same amount of bacteria no matter what part of the media you remove and swap (or use to seed an newly cycling tank)?
http/www.swisstropicals.com/Poret%20Filter%20Foam%20Pricelist.html

 

[daizeUK]

My understanding is that over time dead bacteria will clog the pores in bio media thereby taking up valuable living space.  They can be rinsed to remove surface dirt but the biofilm will cover the dead organic matter underneath therefore rinsing alone will not remove this.  Boiling water would probably do it.
 
As long as you have sufficient surface area to accommodate all your bacteria then of course you will never have any symptoms.  The bacteria will live anywhere they can.  None of us really know how many bacteria we have or how much surface area they need so it seems futile to try to quantify.  How do you know if your bacteria are living comfortably on the ceramic media or struggling for survival on a plastic ornament?  More surface area might not be necessary but too much must be better than too little
 
It seems inevitable that there won't be an even distribution of bacteria across the media.  I think that where the bacteria live depends on the species, some prefer to live closer to the surface and others live deeper in the biofilm.  Logically there would be more bacteria where there is a greatest concentration of food supply for them, so the bacteria at the front would have first dibs and most likely grow a larger population.
 
Are you advising against removing one third of existing biomedia?  If so how much would you recommend?

 

[KirkyArcher]

 

 
Old biomedia will benefit from being partially replaced at regular intervals (6-12 months) anyway, as fresh biomedia will offer greater surface area for existing bacteria to colonise.

 
I have never seen this said anywhere by anyone before, can you provide any scientific support for stating this?
 
Manufacturers of Bio media tend to recommend replacing media at 6-12 month intervals (can't think why as that would involve us spending more money on their products)  
 

 

[Garbolino]

 

Instead of charcoal what would you recommend, as I run 2 fluval 306 external filters on separate tanks & I have biofoam on the bottom then the ceramic things then polishing pads with charcoal on the top

 
Despite lots of recommendations to put polishing pads in the top of your filter trays (including manufacturers instruction), I'd strongly suggest you try your polishing pads at the bottom just above the Bio foam in the same tray, Keeping all the mechanical filtration together (of which a polishing pad is effectively) that way very clean water flows over your bio media and so precious space and surface area is kept open for the bacteria instead of been clogged up with dirt.  Water alone from your other tank will not help with a cycle, 
 
cheers, I`ll move it to the bottom on the next water change
 

 

[Sophie]

 
Old biomedia will benefit from being partially replaced at regular intervals (6-12 months) anyway, as fresh biomedia will offer greater surface area for existing bacteria to colonise.

 
I have never seen this said anywhere by anyone before, can you provide any scientific support for stating this?
 
Manufacturers of Bio media tend to recommend replacing media at 6-12 month intervals (can't think why as that would involve us spending more money on their products)  

All about putting pennies in their pockets. I laugh quite hard reading the replacement Fluval media packets 'change every 2-4 weeks'.

 

[TwoTankAmin]

daize- you need to do a bit more research into the bio-films in tanks where the nitrifiers live. That bio-film is shared by heterotrophic bacteria. You know the ones that consume dead organic matter to live?  When you start looking into this further, you will discover that there is a bunch if information on how the heterotrophs can actually exist in the bio-film from using some things the nitifyers produce.
 
As is my usual custom, here is a head start http/www.ncbi.nlm.nih.gov/pmc/articles/PMC368389/
 

 
Ecophysiological interactions between the community members (i.e., nitrifiers and heterotrophic bacteria) in a carbon-limited autotrophic nitrifying biofilm fed only NH4+ as an energy source were investigated by using a full-cycle 16S rRNA approach followed by microautoradiography (MAR)-fluorescence in situ hybridization (FISH).................... These results indicated that a pair of nitrifiers (AOB and NOB) supported a heterotrophic bacterium via production of soluble microbial products (SMP). MAR-FISH revealed that the heterotrophic bacterial community was composed of bacteria that were phylogenetically and metabolically diverse and to some extent metabolically redundant, which ensured the stability of the ecosystem as a biofilm.

 
If the normal process of old bacterium dying even as new ones are created via reproduction is an ongoing process inside of a bio-film. The whole process would not work very well if this natural cycle of life and death inside the bio-film always cause the demise or the whole thing. I think it works a bit more elegantly than this.

 

[daizeUK]

I know that heterotrophic bacteria form part of the biofilm and feed on decaying organic matter, but I didn't think they would clean up the WHOLE mess (including their own decaying organic waste) so there is no build up over time at all.  Is this what the paper is saying?