Nitrifying Bacteria Question

[anon02]

Thinking forward to when my tank has cycled, I`ll have a colony of bacteria capable of converting 5ppm ammonia in 12 or less hours, Firstly I`d like to know how realistic this 5ppm figure is compared to what is actually produced by a thoughtful community stocking ?

Secondly, if I introduce fish in small batches over a period of time, wont there be some dieback of the bacteria ?

Last of all, How hardy is the bacteria, I`m thinking in terms of major tank maintenance or say a power outage

Tia, Vince

 

[roadmaster]

Bacteria develops in proportion to food available (ie) fish load and some believe that the ammonia method allows for immediate stocking of the tank to it's capacity. Others,,are not inclined to do so for a number of reasons. One must consider the size of the fish being introduced and frequency and volume of fish foods that are offered and that may or may not all be consumed. Is also worth mentioning that bacteria are also influenced by pH,temp, oxygen, and surface area available.
Obviously a small group of tetras would not produce the amount of waste(ammonia) that a large fish, or a group of medium sized fish would produce, but who is to say how much ammonia a group of fish are capable of producing keeping in mind that they produce ammonia on daily basis through respiration,urine,and foods they may have consumed and expelled along with foods that may or may not have been consumed.
For myself,,i choose to stock the tank gradually while quarantining new fishes after the intial few have been added to keep the bacteria active. Nothing worse in my view than patiently waiting for the nitrification process to render bacteria, only to wind up with a tank full of sick fish, and then having to medicate the whole tank which can be expensive depending both on numbers of fish lost,and or the volume of water being treated.
As far as how hardy the bacteria are,,so long as no more than 50 percent is lost through accidental over cleaning,,the bacteria can reproduce quite quickly if conditons are favorable.
Is wise to space out maint so that not everything is not cleaned at one time. One week clean the substrate perhaps one half,the following week clean the filter material in old aquarium water or dechlorinated water (not tap water), and the following week,clean the other half of the substrate and so on.
Many folks run more than one filter and alternate cleaning them in an effort to preserve the bacteria so that not too much is lost at one time. Hope some of this helps.

 

[BigIan]

The processing of 5ppm of ammonia in 12 hrs would represent a massive bioload, more than any well thought through comunity could produce, so no worries there.
If you intend to add your fish in small batches, you simply need to be carful about how many you add and how often. this will depend on the sizer of tank and the bioload already on the filter, 2 guppys in a five gallon with only 1 existing guppy in it will tripple the bioload, however 2 guppys in a 60 gallon fully stocked comunity tank would make no difference what so ever to the bio load. So when adding fish i would certainly add no more than 10-20% of the existing bio load, and keep an eye on the water peramiters afterwards just in case you have a mini cycle.

as for hardy bacteria, during routine maintenance such as cleaning the filter never clean more than 50% of the biological filtration (sponges bioballs ect) and always remember dechlorinator, as for a power outage assuming up to 12 hrs if your filter is an internal type it will be fine, as it is sat in tank water already, and so will stay alive, for an erxternal type simply pump the primer a few times ever hour or so to keep some oxygen in the filter.


hope that helps.

 

[anon02]

Thanks guys, it`s all helping to build up the bigger picture

 

[waterdrop]

I think of building the two bacterial species up to a level where they can drop 5ppm to zero in 12 hours for a week to have little to do with the size of initial stocking that they could technically support. What its really all about is all of us who have done fishless cycles and communicated with lots of other people doing fishless cycles passing on experiences to each other of "what works." What seems to work consistently is that our particular "qualification week" test rarely gets reports back that the cycle failed and the tank went in to mini-cycling once the fish were added.

So what its really about is the amount of "drop-down" room you allow yourself from these big colonies you've built up (so that they'll be robust and reliable, not because you want to overstock) down to the actual realistic initial stocking that you really put in.

A nice bare-tank (or other) fishless cycle (for a first-timer with no mature media) can be followed with more or less any pathway you want to take. The biofilter will now be ready and holding the water perfect for the fish on day one. If you want to follow the fishless cycle with the building of a planted tank then there's no problem, the plants will take over some of the work once they are growing but the backup core of beneficial bacteria will still be well-established and ready to help you should some of the plants die and reverse the water parameters on you.

There are some wonderful threads on TFF outlining ways to handle power-outages.

~~waterdrop~~

 

[anon02]

Thanks WD
What got me thinking about the bacteria (apart from having too much time on my hands) was that I am going to be stocking this tank with tiny shoaling species, giving each introduction time to settle in and I was concerned that the small numbers of small fish introduced over time may not produce enough waste to support the colony

Thinking retrospectively a good fishkeeper wouldn`t know how much waste could be handled because they wouldn`t overfeed or over stock so their numbers would be double zeros

Note to self : check that brain is in gear before letting clutch out on typing finger

 

[waterdrop]

It doesn't matter how small your initial stocking (or subsequent fish addtions) is/are, its still more safe and reliable to have a qualified biofilter (meaning big colonies) and let it "drop down" (meaning yes, lots of bacteria die and the colony size diminishes) to match the small bioload.

I -will- comment however that near the very end of fishless cycling there is sometimes an issue we like to call the "sticking problem" where nitrite(NO2) seems to keep showing a trace at 12 hours and just won't ever seem to get quite down to zero. In tanks where you plan to stock only a tiny fraction (2 or 3 fish in a medium tank for instance) of the capacity of the tank, it can work out to just go on and do the big water change and simply switch to watching to see if you need to do any water changes if the trace doesn't disappear. Usually the trace will disappear and not come back once you stop the large 5ppm dosings and its just the few fish.

~~waterdrop~~