Rummynose and lots of current??

[CanadaPleco]

I am in the beginning stages of planning out my large tank. I have just ordered a 260 gallon 10 foot long tank. I will be keeping my group of L240's and L200's in it so far along with some various LFBN.

I've got a lot of current in here, well I will. I have just ordered 2 MAG18's, so turnover is going to be around 3,000gph. I am wanting to add a large school of rummynose (100-200 of them), but cannot find any info on if they can tolerate this kind of current. Any help would be greatly appreciated.

Rich

[City Bowl]

I have some rummynose tetras in a 120 cm tank with some L46, it is filtered with an Eheim professional 3 and has a strong current running through.
They are not as comfortable in a current like that as I hoped, their noses aren't as red as those I keep in tanks with less current and they do shelter out of the current alot of the time... if I could catch them I'd move them.

[Bas Pels]

Can't say i'm surprised City Bowl has not too positive experiences.

Small fishes will only be able to survive in tiny waters, which generally don't have much current

Larger fishes, I'm thinking about Hemiodes gracilis for instance, life in bigger waters, which might have more current

[CanadaPleco]

Humm well that's not good news, but i am not really all that suprised to be honest.

Time to start looking some more for a good schooling fish, I looked at the Hemiodes gracilis, not bad, but want to keep looking.

Any suggestions would be great.

Thanks

Rich

[MatsP]

To me, 3000gph in a 260 g tank doesn't sound so much - I have turnover rate of about 3000 lph in a 400 liter tank (that's about 750 gph in a 100g tank), and whilst I haven't got any rummynose tetras, I have two other small(ish) tetras, Lemon tetra (Hyphessobrycon pulchripinnis) and Colombian tetra (H. columbianus), and I don't believe those are any better at coping with current than rummynose.

--
Mats

[sidguppy]

Small fishes will only be able to survive in tiny waters, which generally don't have much current

I can't agree with that if I think about fish like Homaloptera, Gastromyzon, Gagata, Chiloglanis and the like.......

there are also various Danio species that can cope with lots of torrent.

but in general fish that have a load of torrent are specially adapted to it

a rough rule to have a good turrent but not overdone is to pump the total tankvolume 3-6x around in 1 hour.

if you over that marge, you're really talking rheophiles; especially adapted fishes to live in rapids and waterfalls.

[Mike_Noren]

It's not just water movement, it's very much an issue of pump pressure. A high pressure pump (the standard type for aquaria) moves relatively small amounts of water in a narrow "beam" moving at high speed, while a low-pressure pump (e.g. Tunze Nanostream) moves a large amount of water in a wider and more slow-moving "beam". 20x water volume turnover per hour from a high-pressure pump is NOT equivalent to 20x water volume turnover per hour from a low-pressure pump.

Also, no free-swimming fish, even salmon, actually spend time in fast current if they can avoid it, they're programmed not to expend energy unnecessarily. So any free-swimming fish will mainly be in relative low-current areas of the tank, only fish adapted to attaching to surfaces (so they're not expending energy) actually hang out in the fastest current.

Finally, it's quite hard to generate strong currents in aquaria. Even with multiple pumps you'll have low current in most of the tank. My experience is that pretty much any fish from larger rivers or lakes can handle any current it is practically feasible to throw at them.

For comparison, here's a quicktime video of my "rockpool in fast flowing stream" 160L aquarium with 30x water volume per hour turnover (2500L/hour Tunze Turbelle, one Fluval +4, one Rena XP3 with diffusor). Note that even though fish movement is clearly affected by the flow, even fish as small as threadfin rainbow (Iriatherina werneri) and ricefish (Oryzias sp.) have no problem dealing with the current.
(Video is pretty big, about 9MB, so users with slow connections beware)
http://mikes-machine.mine.nu/video/160_ ... CN0943.MOV

Here's Corydoras schultzei and Apareiodon hasemani, a true rheophile, foraging in the highest-energy part of the tank:
http://mikes-machine.mine.nu/video/160_ ... CN0944.MOV


EDIT: Duh! schultzei, not schwartzii!

[apistomaster]

I like a lot of water flow but not always a direct curret like that which streams from most power heads and the like.
I use a MaxJet 600, 160 gph power head in all my 20 longs to 40 gal breeder style tanks. The power heads are connected to an Azoo sponge filter Bio-filter #6 which is equivalent to a HydroSponge IV but a little cheaper. I use two per tank with the other run in the airlift mode.
I keep everything from 1-inch discus, Apistogramma spp to current loving fish like most Corydoras spp. When I want less direct current, I just aim the discharge at a corner to diffuse the current. In all circumstances there are always calmer areas available for fish preferring less current.
All the popular aquarium Tetras seem to enjoy having the option to nose into to the stronger currents when they wish. Even Discus will do the same at times pretty much like hamsters use exercise wheels. I also pump air into the venturi outlets of many of the power heads.
In my Heckel Discus tank I have 10 adults in a 75 gal plus a 25 gal sump. The combined flows add up to over 1100 gph. I aim opposing flows to created non-directional turbulence so that really don't have current they have to fight but they do choose to swim in the high flow areas sometimes. I have one of the same sponge and power head sets in their tank, too but the main filter systems are a wet/dry filter using a MagDrive 9.5 running wide open at about 850 gph. The return outlet has a "T" near the surface and a 90* fitting at the terminus and each may be independently aimed. I'm also using an Eheim Classic #2217 as a supplementary filter. Tetras have always done well in with the discus but now that the discus are fully grown, I removed all the other fish. Just left a Bushy Nose and some L134 youngsters in there for the clean up crew. The Heckels are going to be moved to a larger tank this Fall, 100 gal with the same filters.

My point is that one can have a large volume turn over and either design it for maximum directional flows to simulate a stream environment or use deflection and opposing flows to produce a relatively calm environment yet retain a high volume turn over. Tetras like it either way. The only fish I have found that do not do well with so much flow are my wild Betta spp. and Annual Killiefish The reasons why these fish don't do well in my standard set ups seems obvious. In their tanks I only use air lift sponge filters and sometimes, just an air stone barely bubbling. These are true still water species.

[CanadaPleco]

wow, some great info and very helpful input here guys. This is awesome!

I am going to try a small school of 50 or so rummy nose to start with and see how they do. Have got a few months until the tank arrives anyway But I do figure that I can make many areas that are much slower moving current with the use of big rocks and driftwood.

Thanks again everyone!

Rich