south american type aquarium set up

Hi,

I'm looking into setting up a biotope aquarium but it seems to me that's
quite limited to the number of fish and plants.
For instance, the kinds of tetra's and cories differ greatly from the
different kinds of South American River.

I read somewhere that it isn't so much important to look for plants and
fish from the same region but that it's more important to look at their
living conditions. Off course, that would mean you would go for
something like 2. (South American with similar species).

The reason why i want this is to have fish that are happy in the
environment that i can provide (132 gallons, medium light, pH 7.5, KH
5). By taking plants and fish that like these parameters and that maybe
come from the same region, i would hope that this would provide a
thriving community with low maintenance.

Check out fishbase.org and look for the ecosystem lists at the bottom.
The Orinoco packs different fish than the Amazon, Paraná or Negro river.
Is it really worthwile to set up a very narrow scope?
Or could one say, to take my example, i will make a South American setup
and only use fish and plants from South America.
But that seems like such a wide range?! The differences in species,
plants and living conditions seems as varied as if you would mix South
American fish with Asian fish.

I'm beginning to think that the only "correct" way to do a biotope
aquarium is to really "dive" into a certain spot of a river and look at
what fish and plants live there and then rebuild that. But this will
yield a very small variety of fish IMHO.

Another problem: looking at fish from say the amazon river show that the
parameters in that river can change a lot which would seem logical as
it's a very long river.
For instance:
Panda corydoras, pH range: 6.0 - 8.0
Apistogramma Trifasciata, pH range: 6.0 - 6.5
Apistogramma Nijsseni, pH range: 5.0 - 5.

Very different pH needed.
So i'm doubting now and have some options:
1. Go with a strict South American, River based scope for instance
Amazon River
2. Go just with South American but keep similar species together like
tetra's, pleco's, cories, oto's that share the same water parameters.
(mainly pH and KH)
3. Go just with South American and throw in what i like without for
instance looking at the ph levels?

Any advice? Any good links or info on creating biotopes and more
specifically South American?

Thanks

flupke wrote:
<snip>

I would add these fish into a 132 gallon tank, heavily planted and a
filter that has a turnaround of 198 gph (Eheim 2028)
Any comments?

10 x Corydoras Paleatus (5.9cm => 59 cm)
10 x Corydoras Rabauti (5.0cm => 50 cm)
1 x Ancistrus Dolichopterus (11.8 cm => 11.8 cm )
1 x Ancistrus Leucostictus (10 cm => 10 cm)
5 x Otocinclus Affinis (5 cm => 25 cm)
17 x Paracheirodon Axelrodi (3.5 cm => 59,5cm)
15 x Hasemania Nana / Silvertip tetra (2.7 cm => 40,5cm)
15 x Hemigrammus bleheri / Rummy Nose (3.6cm => 54 cm)
10 x Gasteropelecus sternicla / River hatchetfish (6cm => 60 cm)
2 x Mikrogeophagus ramirezi / Blue Ram (3.4 cm => 6.8 cm)
10 x Gymnocorymbus ternetzi / Black Skirt Tetra (6.0 cm => 60 cm)

Thanks