Hi all,
I'm just gonna let the plants grow for a few months, by which point I'm sure that enough bacteria will have colonised my filter.
That's is all you need to do.
In a planted tank you are never reliant on the filter for all of your biological filtration. A lot of people still see plants as a form of decoration, but they aren't, they are the single most important factor in biological filtration. Plant/microbe systems are just a lot much more efficient and flexible than microbe alone systems.
Unlike Darrel I think test kits can be very useful - they work well enough under most aquarium conditions with the major source of error being the operator
Point taken, I'm not disputing that some people will get accurate results using appropriate tests and a scientific method.
The problem I have is that their test results aren't necessarily comparable with other peoples. I actually started on the water testing under the assumption that I could find, reasonably cheap and available, tests and meters that gave reproducible results over a range of water conditions. I could get confidence intervals for a "standard" water sample because I have access to an analytical lab. with an AAS, GC, HPLC, ISE and lab. standard pH, DO, conductivity meters etc. and the trained staff to use the kit.
I started off with de-ionised water, and then added salts to it in various combinations, but it quickly became apparent that certain parameters are problematic with the test kits available to us, and particularly monovalent anions (like NO3-) in solutions with other anions present. It just wasn't a viable approach. The only test kit or meter I could find that produced a repeatable approach over a whole range of water conditions was conductivity, it wasn't the one you would have wanted, but it was the only one where you could get a quick and accurate result with a relatively cheap meter. Dissolved Oxygen would fulfil these requirements, but you need to calibrate the meter before each use, and the meters are still quite expensive to buy.
so adding ammonia ensures that you can build up a big enough bacterial colony so that when you do eventually add livestock, the colony is developed/big enough to deal with the waste?
That is the classical view, and a tank is either "cycled" or "not cycled".
We know from recent research that the traditional view of nitrification, with the bacteria
Nitrosomonas as the sole ammonia oxidising organism (AOB), isn't actually true for aquariums (or any other situations with low levels of aqueous ammonia) and that the bacterial community developed under high ammonia loadings, and at high pH, is different from the community developed at more normal ammonia levels, and that this community is much more diverse and numerically dominated by ammonia oxidising archaea (AOA).
That's a major consideration with the Africans - fish often do best when added in considerable size groups & most species are very sensitive to ammonia/nitrite etc
The only situation I can think of where cycling with ammonia may be a viable option is if you intend to add a lot of Mbuna simultaneously to a plant free tank with carbonate buffered water. You still have the issue of the filter being a "single point of failure", and if you did want to go down this route then long term a "wet and dry" trickle filter would be your best option. I'm not going to pass comment on the "PlanetCatfish" cycling threads linked in <
"http://ukaps.org/forum/threads/best-way-to-cycle-a-second-filter.38958/">, but people may be interested in this more <"
recent thread">.
Scientific papers are appearing all the time now that attempt to quantify the
<"contribution of the various organisms along gradients of oxygen, temperature, salinity, ammonia loading"> etc. and in different types of
<"constructed wetland"> (CW).
It has also been found recently that the bacteria
Nitrospira is the predominant organism oxidising nitrite (NO2) to nitrate (NO3), but that it can also
<"oxidise ammonia to nitrate in some circumstances">.
It seems to me like I'd get bacteria colonising my filter anyway, as ammonia is already present in my tank water, is this the case?
You will, and they will also colonise the upper layers of the substrate, and
<"the rhizosphere around the plant roots">. Once this microbial biodiversity has developed it doesn't suddenly disappear when ammonia isn't supplied, you just get differing amounts of each micro-organism along its substrate gradient. If you want an example of this have a look at a <"
Winogradsky column">. A structured environment with roots in the substate etc. will provide a lot more niche space for microbial colonisation.
Problems can still occur where you have a sudden addition of ammonia, because their will be a lag-phase in the microbial response to greater substrate availability, meaning that dissolved oxygen (or Co2 or NH3) levels can fall, (or build up), respectively causing fish death during the lag phase. This is where the plants come in, and particularly floating or emergent plants which aren't CO2 limited. They will take up ammonia and CO2 immediately, and increased growth leads to greater levels of oxygen evolution.
cheers Darrel
