Dr Mike Oxgreen
Member
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?
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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