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What's wrong with my chili rasboras?

Joined
3 Jan 2016
Messages
383
Location
Woking, UK
There is something wrong with my chili rasboras - they are definitely unhappy, but I can't work out why. When the lights are on, they spend their whole time frantically swimming up and down the glass in one corner of the tank. The corner they've chosen happens to be near the filter outflow, so they have to swim very hard, although other parts of the tank do not have such strong flow. They are pale. They look distinctly stressed. They are not at all fun to watch, because they look so distressed.

The tank is a 25 litre nano tank, 40x25x25 cm. Filter is an external canister (Eheim 2211) with water returned via a lily pipe. I set it up in November, and began cycling it. Near the end of December I was satisfied that the cycling was complete, and I planted my plants. About the second week in January I added 7 chili rasboras, 9 blue velvet shrimp and 3 otocinclus. About a week later I added a dozen more of the blue velvet shrimps. I have also added a bamboo shrimp.

Here are the water parameters:
NH3/NH4: 0
NO2: 0
NO3: about 20-30 mg/l
pH: 6.5
KH: 3°
GH: 5°
TDS: 124 mg/l
Temperature: 23°C

The tank has CO2 injection via a soda stream cylinder and an inline diffuser. The drop checker is down low at the opposite corner from the lily pipe. It is usually green (except today it's blue: see below). I am fertilising with TNC Complete, at a 50% dosage daily to approximate the same sort of nutrient dose as EI.

My lighting is, I admit, pretty bright: a 1200 lumen Beamswork LED light, and an 800 lumen 2x36cm Interpet LED. Also, it's worth noting that when the lights are off altogether the rasboras are calm, and at night they 'sleep' as you'd expect. But even if I switch just one of the lights to its 'moonlight' setting (which is very dim indeed), within minutes the rasboras are beginning to mill about in that corner. So I don't think the problem is due to bright lights, because they do it even when the lighting is very dim.

Today as an experiment I have switched the CO2 off, and run an air pump to drive off the CO2. The reduction in CO2 has made no difference to the behaviour of the chilies, so I don't think it's an issue with CO2. But, and this is very strange, whenever I switch the air pump on the chilies immediately stop, move towards the centre of the tank, and begin behaving much more naturally. This happens within a few seconds, so it can't possibly be anything to do with the aeration effect. It doesn't eliminate the unnatural behaviour completely, but it has a definite and immediate effect. The effect is somewhat temporary, though - they gradually resume their frantic pacing up and down the glass.

I have tried putting a piece of black paper up against the glass at the end where they do this, but it had no effect. An experiment I intend to try is to place a piece of black plastic or rubber inside the tank, so that they can't possibly be seeing any reflections in the glass. Haven't done this yet; will report the results when I do.

The chilies have been in the tank for more than a fortnight, so they really should have settled in and coloured up by now. But they're very pale indeed. They seem to have very red gills though - although most pictures of them do show red gills; it could simply be their pale body colouration that shows up the red gills more.

It's worth noting that I have suffered losses of the blue velvet shrimps, and the bamboo shrimp never feeds and just hides away all the time.

I will upload a video to illustrate this.

Any ideas?
 
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Here's a video link. Notice them frantically milling about in the top right corner. Notice also how pale they are...

th_939BF941-0960-4D7B-8D2E-C8389B787EF9.mp4.jpg
 
Have you tried turning the filter off and then observing their behaviour?
Good suggestion - trying it now.

The filter has been off for about five minutes so far, and there is no obvious change in the chilies' behaviour. They're still pacing up and down the glass with their noses pressed against the edge. The only difference is that they don't have to swim quite as hard to achieve this.

I'll keep it off for another twenty minutes or so to see if anything changes, but obviously I don't want to leave it too much more than that.

I usually use a mixture of rainwater and tap water, but last time I did a 50% water change about a week ago I used RO instead of the rainwater in case the rainwater has any pollutants in it. There hasn't been any improvement, although another water change is due tomorrow so I will once again use a mixture of RO and tap water. If necessary I dose a small amount of Epsom salt to tweak the GH up by a degree for the shrimps.
 
Mine hated co2 , bright lights and high flow
Interesting. What did you do to solve the problem?

So are we saying that chili rasboras are not suited to a planted tank? CO2, bright light and good flow are three ingredients of many people's planted tanks.

Have I simply chosen the wrong fish?
 
Or is it that I don't have enough of them to make them comfortable?

I'm switching my filter back on now. It hasn't really made a difference. :(

Edited to add: I'm trying to allow some hornwort to grow along the surface to provide a bit of cover. I'm also trying to propagate some of it to plant into the corner, to see if I can discourage the little buggers from doing it!
 
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Interesting. What did you do to solve the problem?

So are we saying that chili rasboras are not suited to a planted tank? CO2, bright light and good flow are three ingredients of many people's planted tanks.

Have I simply chosen the wrong fish?

I went completely low tech.
These guys are not suited to high tech.

I'm not saying some people don't have success.
Its not quantity - its a group behaviour issue.

I'd turn off co2 , reduce light intensity and reduce flow for a couple of days and see what happens, then gradually and slowly ramp it back up to high tech
 
I'd turn off co2 , reduce light intensity and reduce flow for a couple of days and see what happens, then gradually and slowly ramp it back up to high tech
Okay, I'm going to give that a go. I've turned the 800 lumen LED off completely, and switched the 1200 lumen LED into its 'moonlight' mode which reduces the intensity to about a quarter. I've turned off CO2, and half-closed the shut-off valve in the outflow hose from the filter.

Goodness knows what this is going to do to my HC and Glossostigma, but I guess they'll recover. Will I get algae? Will my cryptocoryne melt?
 
Hi mike.
I've never kept chillis,but it took an age for my rummy nose tetras to blossom.
Like your chillis...they were pale and panicky...but they're as bold as brass now.
Nice progress on the tank btw.
P.s. what are your otos eating?
 
That's encouraging! Maybe my chilies just need a bit of time and gradual acclimatisation. Will see how the 'low tech' period goes.

The otos are eating a chunk of boiled broccoli stem weighed down with a ceramic ring. They ignored it for 24 hours, but they're all over it now it's been in there for 48 hours. I think you've got to be prepared to leave vegetables for longer than you'd normally leave food, so that it goes nice and soft. Will have to take it out tomorrow though I think.
 
I had an idea last night. It might get me carted off to the loony bin though! ;)

I'm going to try making some decoy chili rasboras. Hobbycraft sell sheets of neoprene foam in various colours very cheaply. If I get a red sheet I could cut out some tiny rasbora-shaped pieces and use a thin black permanent pen to draw the black markings on them and an eye spot. Then thread them onto various different lengths of black nylon thread and tie them all to a weight. Drop that into the middle of the tank, et voilà! A shoal of decoys, calmly hanging about. I think the neoprene foam is a closed cell structure, so hopefully they won't get waterlogged and will remain buoyant.

With any luck, a shoal of decoys placed in the middle of the tank will make them feel more at ease.

Section me now!!
 
That's a novel idea.

And quite mad!

I was pondering this issue last night.

You don't see people putting delicate liquorice gourami into high tech set ups,.boraras inhabit the same environments.
Just a musing.

Good luck with them.
 
That's true, but there are lots and lots of species that originate from black water streams in the wild but are happy to adapt to clear, bright conditions in captivity.

I'll post some pictures of my handiwork when I've done it. Might not be today though.
 
Hi bro try keeping frog bits that will help alot
Do you mean Amazon frogbit or something like that?

I have tried taking some floating plants from my pond. It's like duckweed, but has an attractive almost feathery leaf shape. No idea what it is (picture below, with bees drinking). Hopefully it will grow in the aquarium as well.

It's a bit of a balancing act though, because I have both HC and Glossostigma growing at the front of the tank and neither will enjoy being shaded (particularly the Glossostigma).

3BF8E8C8-4195-4975-90DA-67A6107C5A98.jpg
 
I had an idea last night. It might get me carted off to the loony bin though! ;)

I'm going to try making some decoy chili rasboras. Hobbycraft sell sheets of neoprene foam in various colours very cheaply. If I get a red sheet I could cut out some tiny rasbora-shaped pieces and use a thin black permanent pen to draw the black markings on them and an eye spot. Then thread them onto various different lengths of black nylon thread and tie them all to a weight. Drop that into the middle of the tank, et voilà! A shoal of decoys, calmly hanging about. I think the neoprene foam is a closed cell structure, so hopefully they won't get waterlogged and will remain buoyant.

With any luck, a shoal of decoys placed in the middle of the tank will make them feel more at ease.

Section me now!!
LOVE THAT IDEA.

If you lived near me, I would print this quote off and show it to the mental health team when they come to take you away. I will reassure them that your tank is in good hands. :)
 
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