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Re: More FishLess cycling

> I would have to say that this is not true, at least not how I think it is
> meant.  The tank would cycle from Ammonia to Nitrite, and then more seed
> culture would have to be added for the nitrite to nitrate phase.

No, it doesn't to any detectable levels. Plants are very quick if given the
proper nutrients to remove all the NH4. No NH4, no NO2.
If you add a great deal of food or/and fish etc right off the bat, that's
asking for trouble and no one advises this for a plant tank. Add algae
eaters for the first month then add your main fish.

Adding too many fish will tax even the most cycled tank and produce enough
NH4 for the fish and the algae. NH4 is very good at inducing algae to grow,
sporulate etc. Even a great biofilter cannot keep up at some point.
A filter is simply a backup in case you have too many fish for the plant's
uptake rate(s). If the tank is stressed by not adding enough PO4 or K, that
will slow NH4 and NO3 uptake. So dosing can cause problesm if folks don't
keep up on it.
Adding mulm, which is organic detritus and lots of bacteria (which is the
thing folks are waiting to grow for weeks when doing fishless cycling in the
first place) "cycle" the tank immediately. There is no wait, no build up of
any NH4/NO2.

 I don't
> think much of the nitrite to nitrate bacteria would survive because
> initially there would be no food for them.  At any rate it wouldn't support
> much of a biological load unless you added a lot of substrate or mulm from
> the seed tank.

You are missing the plant part, what do plants use as "food"(NH4, NO3), what
do they give off(02)?
Bacteria will not have any food when there's a moderate fish load due to the
plant's removing all the NH4 before the bacteria get to a large amount of
the NH4. Bacteria are simply a back up for the plants. The Bacteria in
question consume O2, they don't produce it. Plant do and remove other things
as well. They also look nicer than bacteria.

Now if you are trying to keep too many fish in a plant tank/plan on feeding
a great deal of food etc, then it is wise to use a wet dry filter which is
the best thing for taking the excess NH4 that the plants cannot
process/assimilate and turn it into a much more benign NO3 which the plants
can use and which does not induce algae nearly to the same degree.

> This method can substantially shorten the cycle but not
> eliminate it.  It could eliminate it if you only want to add a tiny fish
> load.  The whole tank has to get colonized, and that takes some time and a
> food source.  The only way to get that without fish is to add a food source
> over time.  I still don't see the advantage or understand why one would want
> to drop in a ton of fish at once, unless one were moving or something like
> that.

I never suggested to add a ton of fish. Why would I? That's not a good place
for the fish or the plants.

 Why? At some point the capacity of the plants to absorb all the fish waste
in the form of NH4 is exceeded. A slight amount builds up and you get an
algae bloom. A balanced fish load of moderate size works well. Having a
large wet/dry filter helps convert the NHG4 quickly and eventually to NO3
which the plants will use fast but the algae don't. The filter is simply a
back up for the plant in a sense but the bacteria are not removing the NO3
end product unless they are denitrifiers. I'd rather the plants do the NO3
removal personally.
> Personally, I run filterless tanks so this is totally academic to me.

And do you have a lot of fish/light/feed heavy? I doubt you do. But the same
thing will apply here to these tanks. The bacteria is there in the gravel

> However, I do fishless cycling of planted tanks.  The plants go in about two
> weeks before the fish and I start feeding them immediately. Fish only go in
> when the initial die back and wobble are over, basically when the plants
> begin to 'take' do fish go in.  Fish and plants together is just to many
> variables in the new environment for me.

Well that's finre as long as you do not add light until you have no NO2/NH4
and don't add plants till after wards.

In the meantime while you are waiting, I have a jamming plant tank.

> I believe fishless cycling may be reasonable in marine tanks where the fish
> are very sensitive/delicate/expensive.

Yes, I agree those folks are more dependent on the bacteria generally but
macro algae are suitable for nutrient removal at high rates as well. Some
use that in their refugiums. Leng's systems works like that and I might add
it does work quite well.

FWIW, they have a system where they have not done any water changes for a
couple of years on a Discus tank and the fish have bred.

Tom Barr

> Adam