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Massive flow- unhappy fish?

Sacha

Sacha

Member
Joined
3 Jan 2014
Messages
992
Location
London
This is a question about flow in my 125 litre tank.

This is a co2 injected tank. I am running an Eheim Professional 3 (600) filter which is rated at 1250 lph. In addition to this, I am using an upgraded Juwel internal filter with a 1000 lph pump.

Today I attached an extra spray bar to the outlet of the internal filter. So I now have two spray bars, both facing forwards towards the front wall, and angled slightly down.

This is clearly a huge improvement for my plants. But now I'm a bit concerned about the fish. The flow now is massive. The danios seem to love it, but the cardinal tetras seem a bit spooked. And the cory always seem miserable anyway.

I guess my question is, will very fast flow bother my fish?

Cardinal tetras
Pentazona Barbs
Corydoras Trilineatus
Zebra Danios

Cheers.
 
Hey Vazz,

I am using the Eheim spray bar! I believe it is "eheim installation set 2"? Or maybe installation set 1.

ne3ehyge.jpg


3anuhany.jpg


anuda9up.jpg


Sorry- I know these are not the best pictures but hopefully you can see what I've done.

The spray bar pieces like the one in the last photo can fit around the Juwel outlet pipe. So the black pipe outlet from the Juwel can fit inside the spray bar piece with a bit of force.

Hope that makes sense??
 
P.S I am using the old APS pipe work for the External filter. So the external spray bar is APS.
 
I'd say that was too much flow for cardinals and cories who aren't known for strong current swimming. Why not double drill the spray bar? You'll have the same filtration but it'll half your flow rate.
 
Thanks I might try that. I'll wait and see how the fish behave over the next couple of days. If I do this, how should I drill the holes?
 
You have lots of options of where to drill. If the current line of holes is at three o'clock on the circle I'd add a new line at one o'clock. That way it's not so close that it will weaken the structure of the pipework and still allows you to choose some direction in the flow within a quarter of the circle's angle (if that makes sense to anyone).

Alternatively you can dot a few extra holes all around the pipe to just reduce flow along the main line. However you decide to do it, do it sparingly to start with and retest. You can always drill more holes if you want more but filling in ones you didn't want is a pain.
 
Ok but using what kind of a drill? :s

I'm going to add some more media to the internal first just to reduce the flow a bit.
 
Oh I don't know sorry. When I did it myself I borrowed a drill from a friend and just chose a drill bit from the box which was a similar size to the holes already in the pipe. I think it was a small brad-point bit. I used sandpaper to smooth down the rough bits afterwards.
 
The other thing you can do is enlarge the holes that are there and this will also slow the velocity down.
 
Glad the filters up and running :) the rated flow is 1250 if i remember rightly on the eheim thats a good 10x turnover and a top notch filter, i doubt you even need the internal running on it at all. My tank was 240l that it was on but low tech and it still had a decent flow. I used to have a juwel rio and ended up removing the internal filter completely using a sharp razor/stanley knife blade and running it down the sealant that holds it to the tank. Left nothing behind at all and was far better without it.
 
I'd take the old filter out, or at least turn it off. The pro 3 (600) ishould be plenty of filtration/flow for that tank size.
 
It probably looks worst than it is, you could always change one of the spray bars for a duckbill or lily pipe.

I would get a small set of drills and open out a few holes at a time, but only slightly. I wouldn't bother with the offset holes, this didn't work out very well for me. There's a fine line when expanding the spray holes from vortex to seemingly no flow.
 
I'd love to expand the spray bar a bit but I'm terrified to drill into it because I'm sure I'd mess it up.

I might have to go back to using the 600 lph pump for the internal filter (currently using 1000 lph pump).
 
Agree with James O. Can you remove the internal or is it fixed? The other less permanent temp fix is to adjust the flow lever on the eheim external?
 
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