FAQs on Odessa
Related Articles: Barbs, Danios &
Rasboras, A Barbed Response; Wrongly maligned for being
fin-nippers, barbs are in fact some of the best fish for the home
aquarium by Neale Monks
Related FAQs: Barbs, Danios, Rasboras 1, Barbs, Danios, Rasboras 2, B,D,R Identification, B,D,R Behavior, B,D,R Compatibility, B,D,R Selection, B,D,R Systems, B,D,R Feeding, B,D,R Disease, B,D,R Reproduction,
Puntius padamya health; water chemistry issues; was:
Thorichthys in community tank -- 11/09/11
thank you for a primer in water chemistry in your email, along with
your comprehensive articles on this site. I've read up properly and
realise with some sadness I won't be able to keep loaches in London
water. I'm honestly a little curious as to why the fish shops stock
so many species that won't survive the local water -- hard to
imagine the average hobbyist buying RO water/collecting rainwater?
<It's a bit more nuanced than this. Yes, you can keep soft water
fish in hard water. And that's why fish shops sell them. The
problem is that they generally don't live as long as they do in
soft water. Neon Tetras are the classic example, and these commonly
live only a year or so in London tap water, compared to 4-5 years in
soft, slightly acidic water conditions. To be fair, there are some soft
water fish that seem to adapt just fine. Corydoras catfish, for
example, seem to do well in hard water provided other parameters, i.e.,
water quality and temperature, are acceptable. Other tropical fish have
been farmed for so many generations that they've become adapted to
a wider range of water chemistry conditions than their wild ancestors.
Angelfish are the classic examples, but Discus are also a lot more
tolerant now than they were originally. Some of the more adaptable
loaches would fit into this category too: Weather Loaches and Yo-Yo
Loaches are the two that spring to mind. Nonetheless, there remains a
very large selection of soft water fish that are risky investments if
you have a hard water aquarium: Neons, Cardinals, Harlequin Rasboras,
Dwarf Gouramis, etc; most of the other commonly traded ones are soft
water fish too, including Clowns and Kuhli Loaches. Now, the better
aquarium shops in London do indeed have soft water sections, for
example Wildwoods in Enfield, probably the store with the biggest
variety of freshwater fish anywhere in the area. Most of the Maidenhead
Aquatics stores I've visited seem to work the same way, keeping the
more difficult soft water fish in soft water tanks. Even if you
don't want to invest in an RO filter (they are expensive to buy and
run) then rainwater isn't all that difficult to collect and store.
That's what I do, and apart from the water butt and a couple of
5-gallon buckets with lids, it's a free and easy way to do
Now for another question: I've got a school of Odessa barbs in my
tank, and they're doing so-so. I bought them in two batches, six
specimens in the first batch. Two of them got very listless already a
few days after purchase. They stopped feeding, were only kind of
twitching on the spot in a dark corner for a couple of days, got darker
in colour and then died. I noticed the dead fish had become quite dark.
Two more of that first batch are now hiding, twitching and darkening. I
expect them to die as well.
Any idea what could be the matter with these fish? Shall I remove them
to avoid contaminating the rest? Anything I can do to help them?
<Puntius padamya is generally not a problematical species. Water
chemistry isn't a major issue with this species, so assuming your
tank has the same sort of water as the retailer's tank, that
shouldn't be a cause of trouble. Copper and/or ammonia in your tap
water might be issues, so do check your water conditioner neutralises
them, alongside Chloramine and chlorine. Next, check water quality in
your aquarium; as always, you want 0 ammonia and nitrite. Look to see
that your filter is providing adequate circulation; these fish inhabit
streams and dislike oxygen-poor water. Try lowering the waterline by a
few cm, so that there's plenty of splashing. Clean out the filter
too. See if the combination of better aeration and faster water flow
helps. I wouldn't buy any more of these until things have settled
down. You might have a bad batch. Do visit your retailer: are the
specimens there looking healthy or off-colour?>
I removed the pesky single Glowlight Danio, to try and diminish stress
on the Odessas.
thank you! Fredrik
<Most welcome, Neale.>
Re: Puntius padamya health; stocking 180 l
thank you again for your detailed reply. Three out of the first batch
of six Odessas have died and a fourth one is hiding, not feeding, going
darker. She keeps opening and closing her mouth rapidly, and her belly
<Not good. Does sound like environmental stress of some sort, or
perhaps poisoning. Hard to be sure, really.>
Her scales are not protruding. The second batch of ten Odessas appear
healthy and happy, so maybe I got a bad first batch?
I increased aeration. My nitrate readings have become slightly higher,
between 30 and 40 ppm. Ammonia and nitrite consistently 0. I downloaded
a detailed water quality report from my council (see attached), can you
see anything I should try and eliminate? I use Tetra Aquasafe water tap
<Water quality is excellent in terms of drinking water, but you do
have standard London "liquid rock" and you need to choose
species accordingly. While I doubt this is what has killed your Odessa
Barbs in such a short period of time, it's a factor you can't
exclude in terms of long-term care.>
As soon as the Odessas have stabilised, I'm would like eventually
to add some Swordtails following your advice. Beautiful fish that suit
my hard alkaline water.
<Correct. Since you're in London, check out both Wildwoods and
Wholesale Tropicals. Both of these get oddball livebearers, for example
the excellent Xiphophorus alvarezi, the Spotted Swordtail.>
Current stock (180 l planted):
2 x Ellioti cichlid
13 x Odessa barb
2 x Bumblebee goby
1 x Bristlenose Pleco
1 x Apple snail
Would swordtails be suitable tank mates for them? How many could I add?
How many males/females?
<Swordtails can be "nibblers" on Apple Snails, but are
otherwise fairly good, if aggressive, community fish. Keep at least two
females per male, and keep either one male or at least 3; if you have
two males (alongside four or more females, of course) you'll
probably find one male bullies the other continuously.>
Would the Swordtails be better "dither fish" for my big bully
Ellioti? He doesn't seem to care about the tiny Odessas, so Ellioti
jr is getting all the heat at the moment'¦
<Swordtails are first-rate dither fish. But that doesn't affect
bullying by one of your two cichlids. It's "target fish"
that do that. Classic choices are medium-sized, territorial,
fast-moving midwater cyprinids like Red Tail Black Sharks, but I
wouldn't recommend one of those for your aquarium. It's too
small and the water chemistry isn't ideal.>
many thanks, Fredrik
<Most welcome, Neale.>
Re: Puntius padamya health; Ellioti chasing... Odessa Barb hlth.
Hi WWM again,
update on our sick Odessa: her belly has now swollen up even more,
still no obvious pine-coning. She is hiding behind plants and not
feeding. Shall I better remove her from the tank to avoid her infecting
the others? Is there any treatment I can try?
<Honestly, I'd euthanise this fish, unless you have a completely
separate aquarium where you can treat it.
In all likelihood, she has a systemic bacterial infection, and these
are difficult to treat in small fish. 30 drops of clove oil stirred
into 1 litre of aquarium water will create a bath that painlessly kills
All other Odessas appear healthy and happy.
<Good. May be a one-off.>
I have lowered the tank temperature from 27 to 25 degrees and I would
say the "alpha" Ellioti is slightly less aggressive than
before. Could this be the case?
<Yes. Cichlid aggression is very sensitive to temperature. In short,
cichlids become aggressive mostly when they're about to breed. In
the wild they typically breed when the water is warm, and during the
cooler part of the year they are quiescent. Varies, of course, but as a
general rule, if you lower the water temperature, you'll find
cichlids cause fewer problems.
Do be aware of the minimum temperature requirements for a cichlid
species though. Too cold, and they'll get sick.>