small/medium tetra or other for fast flowing water

[CanadaPleco]

Alright so I have a large 300g, long tank. The flow rate in the tank is huge, and it contains some large fish also, Geos, Red hooks, Sevrums etc. Wondering if anyone can suggest some smaller schooling fish that may not get eaten and like a fast flowing tank. The tank is kept at usually 80 degrees or more.

[Jackster]

I would try some Cochu's Blue Tetras (Boehlkea fredcochui) but I can't be sure
they won't get eaten. They are a fast swimming aggressive little Tetra so I think
they would work well. Try 6 of them to make sure they will survive before you
throw in a couple dozen. My second suggestion would be Bleeding Heart Tetras
(Hyphessobrycon erythrostigma) as I have housed them with African Mbuna
in the past and they faired pretty well considering they were in with the wrong
tank mates and in the wrong type of water as well. I would still try a few before
you add a larger group just to make sure the can "hang" with the crowd.

[drpleco]

A lot of folks recommend Congo tetras for high flow tanks. You could also try filament barbs. They like fast current/high oxygen and get about 4-6".

[sidguppy]

he's got a South American setup; I don't think he wants African characins or Asian barbs in there

thought about Hemiodopsis?
it's bigger than a tetra and it sure likes to swim. it's a docile fish that doesn't harm Earth Eaters.

another fast swimmer is Triportheus and that one definitely can handle a lotof current.
Triportheus angulatus is in the trade, sometimes other species turn up.

a good thing about Triportheus is that it dwells in the top layer; few characins do.

both species can handle heat without any problems.

beware of Abramites or -worse- Anostomus and leporinus.
they're tough, good looking, colorful and strikingly patterned; but these are all nippers and Geophagus can't handle that.

[MatsP]

How fast flowing is "fast-flowing"? I can't imagine that you have more than 15x turnover on such a large tank - which should be fine for most things that isn't overly still water fish.

--
Mats

[Bas Pels]

a definition for fast flowing water I once read was 1.25 meter a second - close to 4 feet a second

I once did some calculations, this is nearly exact the speed of the water through the piping of an Eheim pro II (1000 l/hr, 18 mm hose)

Wat we, in a tank, consider as fast flowing, is in fact almost stagnant water

[CanadaPleco]

ooh, never thought of Hemiodopsis Gracilis, very nice fish, thanks for the advice

Yes I know it is not really fast flowing water, I am a whitewater kayaker so know quite well what fast water is I've got 3600 gph going through this tank, and it is with the sump volume around 300g in size.

[MatsP]

So how big is the actual tank itself? I expect the sump is less than 100 gallon, so the overall turnover in the main tank is still around 15-18x maximum. If that's a bit unevenly spread in the tank too, the dither-fish will end up finding a quieter place if the need to.

--
Mats

[CanadaPleco]

Tank is LONG.... 10 feet long x 2' x 2'. 6 returns come into the tank and there is an over flow at the end to simulate sort of river like flow. Sump is 75g, 4 foot tank.

[Mike_Noren]

I agree with Bas Pels, you can put any tetra in there - the current will not be a problem, because it's really a quite slow flow.
Just as a point of reference I held neon tetras in a 160 liter tank with a total flow of 5000 L/h and they had no problems (they really didn't like the metal halide light though, and would avoid the light cones).

To minimize predation you could use high-bodied tetras, like Silver Dollars or, for a smaller & non-plant-eating alternative, Black Widow tetras.

[MatsP]

Colombian tetras are also quite large and high bodied, but gentle temperament and not plant-eating. Grows to about 2-2.5", and have nice red fins and bluish tinge to the body.

--
Mats

[CanadaPleco]

Ohh the columbian tetras are nice also! I have red hooks (5) so that's my Metynnis family in the tank. Really like the columbian tetras though And at 2.5" thats a nice size. Thanks!

[sidguppy]

I wouldn't trust Red Hooks (wich is a Myleus species, not Metynnis btw) with small tetra's!

there's still a bit of 'piranha' in a Red Hook; some are docile, but others tend to see smll fish as extra protein-snacks to their veggie diet.

why not more Red Hooks? 5 isn't a shoal.
a 3 meter tank/10 footer can easily hold 15 or so and then you'll see beautiful synchronized swimming behaviour.