FAQs on the Rainbowfishes Health/Disease 3
Fishes at the rainbow's
introduction to the Atheriniformes, the Rainbowfish and
silversides by Neale Monks
Rainbow Disease 1,
2, Rainbow Disease 4,
Rainbowfishes 2, & FAQs on:
Rainbow Systems, Rainbow Feeding,
Stringy white poop, many deaths
I've been having a bit of a problem with my Dwarf Neon Rainbows
and I'm at a loss at this point. I'll start the story by stating that
through the whole ordeal ammonia and nitrite were zero, nitrate was less
than 5, water
changes were done weekly at least and whenever else I thought they were
needed. I ordered 9 online nearly 2 months ago; 3 males and 6 females
all came alive but covered in ich. I was expecting ich, so they went
into a 10 gallon quarantine tank equipped with a cycled filter off an
established tank. I raised the temperature to 86-87 and after 2 days all
ich was gone but I left the temperature up for a week or week and a half
just to be safe.
All fish initially ate well. I fed almost exclusively frozen foods
(brine shrimp, Spirulina brine shrimp, bloodworms, daphnia, etc. I had
over 10 varieties) with New Life Spectrum, Hikari Micron, and Sera Onip
fed on mornings when I was running late. After a week the male that got
picked on a bit developed dropsy overnight and died within a couple
days. Now, after having a bad experience at a local fish store with
internal parasites I automatically treat all the fish I get. I treated
with General Cure first (has never proven effective at treating internal
parasites for me but it's proved useful for other things, so I use it
before PraziPro) and during
that treatment, one of the males stopped eating and developed white
stringy poop. He was like this for a few days before he began breathing
very heavily then died. I researched and researched and everything came
internal parasites. I used PraziPro and at some point fed Hex-Shield
(which I had forgotten I had) and the remaining 7 all had nice red poop.
Yay! Or so I thought.
Some number of days later a female got white stringy poop, stopped
eating, began breathing heavily, then died. Down to 1 male and 5
females. More research and forum exploration led to Hexamita or Malawi
bloat. A Hexamita recommendation was to feed food soaked in Epsom salt.
Everyone but one female ate. The recommendation for one that doesn't eat
was to squirt the Epsom salt mixture down her throat. I figured since
she would die as soon as she got to the heaving breathing stage anyway
there was nothing left to lose. I filed the tip off a syringe I got from
the vet, gave her some Epsom salt mixture, and the white poops stopped.
Yay! Other recommendations were to use metro, so I ordered that just in
case. I did it once more and then it was time to pack the fish up for a
move across the state.
All rainbows survived the initial trip but the one female died the next
day. They were kept in the ten gallon QT for a few days but since the
remaining ones all appeared healthy and I really needed the tank off the
floor, they went into a 20 high. One male and four females left. None of
my frozen food made the trip. A relative lent me a cooler she swore was
incredible, yet all my food turned to mush. Everyone got stuck with
Repashy and pellets since finding pet stores here is hard, but at least
that made looking for healthy red poop easy. The remaining 5 fish were
all healthy in the new place for 3 weeks until the other day. One day a
female was suddenly breathing heavily and bloated with white stringy
poop. She didn't stop eating before then and none of the other fish,
minus the initial dropsy case, had bloated before death. Now, I had been
feeding pretty heavily because it kept them from decimating the shrimp
population while the plants grew back (a bit of melt since they got
packed up days before the move), so I fasted them. I was gone the entire
next day and didn't look at my fish at all. Yesterday I counted 3
females and 1 male. The shrimp were picking at a small piece of white
meat, the Hypancistrus was part way out of his cave (very rare).
Clearly, the female was turned into a meal.
I'm at a loss as to what to try next. Your key leads to Malawi Bloat
since there's no fungus or wounds appearing on the fish, but they aren't
cichlids. They've been treated for internal parasites and every time I
think everyone is healthy another comes down ill. What is there left for
me to try? I have one male and 3 females left. They look healthy and the
poop is healthy but I've learned that can change overnight.
<Hello Sabrina. Like you, my gut reaction here (if you pardon the pun)
is that we're looking at Hexamita or some similar intestinal parasite.
While you have used Hex-Shield, this is a "good" food rather than a
While it contains vitamins and minerals essential to good health, it
doesn't contain Metronidazole, which is the medication you want here. So
that's where I'd be going. Something like Seachem MetroPlex, for
Epsom Salt is often used alongside Metronidazole because it does help to
reduce swelling and constipation, but it isn't a medicine _per se_, so I
wouldn't expect it to treat this problem as it is. Squirting Epsom salt
into a Rainbowfish sound like a non-runner to me, more than likely
causing severe osmotic stress even if the experience doesn't harm the
fish psychologically. Ideally, use Metronidazole alongside a reliable
antibiotic, Nitrofurazone being particularly popular among aquarists. If
you have some other antibiotic kicking about, I dare say it'd be fine
though. At the same time, do ensure a number of other things. Firstly,
lots of oxygen; secondly, appropriate water chemistry; thirdly, a varied
diet with some fresh greenery (gut-loaded brine shrimp are handy); and
fourthly, keep nitrate levels as low as practical. Hope this helps,
Re: Stringy white poop, many deaths 1/17/18
Thank you for your help!
I have a small bag of Metronidazole. The tank is full of snails and
shrimp and I can't set up the quarantine tank right now, so do you
recommend mixing the Metro into some Repashy or bloodworms?
<Getting medicine into fish via their food is usually more effective
than adding to the water. But dosing can be tricky if the fish spit out
some of the food. I'd tend to follow the instructions on the package, or
advice from the vet, rather than simply improvising.>
In terms of feeding greenery, I used to have Spirulina brine shrimp and
emerald entre but they went bad during the move and I can't find any
around here. Tiny town problems.
Would crushed algae wafers, cucumber, zucchini, lettuce, or broccoli
<The algae wafers are a useful staple for any community fish, and should
be part of their regular diet. Spirulina flake food (sold for
livebearers) is also an excellent staple. The other green foods, if
eaten, are all good additions to their diet.>
I also have some Cobalt pellets with Spirulina and probiotics. In terms
of antibiotics, I have Kanaplex, Furan 2, ParaGuard, and Fungus Cure
(says it treats secondary bacterial infections). I've always been
partial to Kanaplex, but which do you recommend?
<Kanaplex would also be my first recommendation here. The others are
more or less antimicrobials rather than true antibiotics.>
The tank does have an air stone. In terms of water chemistry, ammonia
and nitrites are always zero, nitrates less than 5 (usually zero. I dose
a little for the plants), pH around 7.5, 10 dGH, 11dKh.
<All sounds fine.>
Thank you again,
<Good luck, Neale.>
Re: Stringy white poop, many deaths
The directions that came with my Metro recommend 2 teaspoons per pound
<That's a lot of fish food!>
I did the math and I need approximately 0.014 tsp per cube of
bloodworms, which is just slightly less than 1/64, which is the smallest
teaspoon measurement I have. I'll just add a little less than 1/64 tsp
and be generous with the Garlic Guard.
<What's the garlic for? I would not be adding random 'cure all'
chemicals alongside specific treatments.>
The math for Kanaplex will have to be done later and hopefully the fish
will eat it. Perhaps they just need to be starved for a day or two as
Alternatively, I could mix it with daphnia (only other frozen food I
could find) but I think the hypan is more likely to eat the bloodworms,
since eating the last dead fish more than likely infected him too. Do
you have a preferred brand of Spirulina flakes?
<Not really; they're all good!>
New Life Spectrum is my go-to brand but they don't make them and neither
does my second favorite, Omega One.
<Understood. I've used the Tetra brand, but pretty much any should work
I hope you're having a wonderful day!
<Off to donate blood now, so wonderful isn't quite the word, but
hopefully useful! Cheers, Neale.>
Re: Stringy white poop, many deaths 1/20/18
I hope donating blood went well! At least as well as it can go anyway.
Personally, I despise needles.
<I think most people do. The burden of being O-neg... constant demands
to be sucked by medical vampires!>
Frankly, I'm too lazy to deal with fresh garlic and without it, I find
the Pleco won't eat anything medicated.
<Really? Fair enough.>
Thus far the remaining 4 rainbows are alive and still eating, though one
female has begun hiding a bit. Should she, or any other infected fish,
stop eating how do you recommend I treat it? All forums and sites online
say if the fish are to the point of refusing food the medication should
basically be squirted down its throat.
<Whilst viable with large fish, with very small fish there's more risk
of either stress, handling, or the pressure from the nozzle doing
serious damage. I'd be extremely cautious before doing this sort of
thing. Many medications can be added to the water. Less effective, but
I'll do it if I must, but is there another alternative?
The consensus seems to be that treating the water will do no good.
<It's less effective, but not ineffective. Fish do drink, and in
freshwater, they can't help but absorb things from their environment.
Dosing is important, but also is removing carbon from the filter -- a
common oversight that causes "false negatives" where people use a
medication and find the fish stay sick. High oxygen levels and rapid
turnover will cause medicine to be broken down by the biological filter,
and simply high levels of biological activity, such as algae, let alone
the fish, can have a similar effective. So yes, getting the food into a
fish is better. But many medicines work reasonably well added to the
water. My books recommend 50 mg Metronidazole per 4.5 litres (about 1.2
US gallons) -- so a single 200 mg label would be a bit under 5 US
gallons. Furthermore, it is recommended doing 3 treatments, the first on
day 1, the second on day 3, the third on day 5, with a 25% water change
before the next dose. Make sense?>
Do you personally do any medicating or treatment of new fish? Does it
differ whether the fish are captive bred or wild caught?
<Funnily enough, farmed fish are actually more risky! Wild fish tend to
be in very good shape, though external parasites like flukes are not
uncommon in a few cases (such as Bichirs). Farmed fish tend to be
maintained in high numbers in small ponds or tanks, so cross
contamination is very common.
Drug use is ubiquitous on farms, too. Of course once you mix the fish in
the retailer's tank all bets are off, but no, I don't routinely medicate
new fish, but I may well quarantine if that's a possibility. That said,
I'm pretty ruthless about not buying fish from dodgy shops, and I avoid
delicate species like the plague! Really, fish are actually
astonishingly disease resistant, all things considered -- they're
swimming about in what are effectively bacteria-laden Petri dishes! It's
either bad luck, bad genes, or bad housekeeping that leads to problems.
I haven't bought new fish in six years now, and can't remember the last
time I medicated them.>
Oh and also, you said Hex-Shield is just a good food. What do you
recommend its use be? I spend a fortune on it so I'm definitely using it
one way or another, but is it actually helpful with ill fish or just a
decent addition to their usual food rotation?
<I'd go with the latter. Hexamita -- or at least Hole-in-the-Head --
probably has some relation to diet, the lack of fresh greens being
widely discussed. So, any food laden with greens or supplemented with
vitamins has the potential to "shield" against Hexamita. That said, any
number of ways to achieve the same thing -- good quality flake, slivers
of various fish meats and seafoods, periodic offerings of
Spirulina-loaded brine shrimp, cooked peas now and again -- all these
things, if used together, should provide a good, balanced diet without
the expense. It's much the same as vitamin supplements with humans:
sure, we need what they supply, but if you're eating salads and fruits
and oily fish and all the rest of it, you'll be getting those vitamins
anyways, and it's not like your body can store them, so having extras
Thank you for all your help!
<Most welcome. Neale.>
Re: Stringy white poop, many deaths 1/23/18
The length of time to feed the medicated foods differed greatly between
the Kanaplex and Metro so i went with the shorter duration, but now one
female is bloated and breathing heavily. There's a small chance she is
eggs because there has been some spawning activity in the tank, but im
leaning towards needing to medicate a bit longer.
<Indeed; seems reasonable.>
Your books recommend far higher dosages than my medication or what I've
read online. May I ask what the books are?
<"A-Z of Tropical Fish Diseases and Health Problems" -- an oldie but
Can they be purchased online?
<Oh, I'm quite sure they can.>
Maybe the dosage I mixed with the food is too low.
<Possibly. I double checked, and yes, it's 50 mg per Imperial gallon
(about 42 gram per US gallon, by my reckoning).>
Would it be reasonable to expect the fish were sent to me already with
<Absolutely. There is some belief that Hexamita is ubiquitous in the
aquarium hobby. It's more about asking "what's happened to these fish
that's made them unable to resist the Hexamita" in which case we look at
things like poor diet, high nitrate, etc.>
They got a wide variety of frozen foods nightly, including Spirulina
brine which was fed usually twice a week.
<A very useful fish food.>
Morning feedings are always New Life Spectrum, Hikari, Sera, or if I had
time crushed Cobalt with Spirulina and probiotics or crushed Omega One
shrimp pellets. I don't have time to crush things often. They also have
always gotten Repashy Community, sometimes Grub Pie if I forgot to make
more Community. If i got out too much fish for the Hypan they got
flounder, clams, shrimp. All my tanks got peas and green beans a couple
times a week,
though the green beans don't seem to be a favorite. I would think this
is enough of a variety even if I wasn't feeding Spirulina flakes
<This all sounds fine.>
On another note about food, I recently saw freeze dried peas with a
grinder lid being sold as a fish food supplement. Thoughts? Would it be
any good soaked in water before feeding?
<If the fish weren't getting any greens, then sure; but your fish are
getting such a good diet, this seems like a needless expense. Besides,
fresh greens and Spirulina probably trump dried peas when it comes to
Sent from my Galaxy Tab A
<Sent from my computer! Neale.>
Re: Stringy white poop, many deaths
Oh my I forgot to change my signature! I really must get around to
I ordered a used copy of the book from Amazon for just under $12. I'm
<It's a brilliant yet frustrating book. Lots of info. It's really my
go-to for fish healthcare. Masses of text. Very little filler. But the
layout of the book is insane. Three chapters subdivided alphabetically
using a system I still don't understand. Luckily, it's written by some
very expert aquarists who are very well known in the UK, so it's well
worth the effort.>
I can't find much direction for mixing Metro with food online, other
than stumbling upon one WetWebMedia article saying to use a 1% mixture.
That's too much math for me. Once I finished Calculus my brain checked
out. Now all I get to think about is various sciences. Since one scoop
didn't seem to cut it I'll try two, mixed with the directed amount of
Kanaplex. The one female is looking really bloated. Would it be ok to
mix a bit of Epsom salt
in? I'll be using daphnia instead of bloodworms to help in case it's
<I would not add Epsom salt. Epsom salt will exert an osmotic effect on
the fish that could be dangerous. It'd be similar to having someone eat
a bowl of table salt.>
All the transport would definitely be what made them unable to resist
Hexamita. They were shipped to me covered in ich, which started the
whole ordeal, then I moved and the heat packs failed. All the fish
cold but not freezing. The only deaths were the female Rainbowfish that
had white stringy poop already and my last Rummynose tetra from a fish
store who's quality had gone way down. Every fish I bought from that
almost instantly, but the group of wild caught rummies I got from a new
store were, and still are, in excellent shape.
<This is starting to sound like a very plausible explanation. Stress,
bad luck, and the latent Hexamita infection could easily interact in the
way you suggest.>
Re: Stringy white poop, many deaths 1/30/18
Unfortunately, the female is not improving.
<This is a Rainbowfish, right?>
She's still breathing heavily, still bloated, and has refused to eat for
a few days now. I can't set up a quarantine because my spare heater died
and there's absolutely no money for a new one, but I do have a small
(1/2 gallon I think) container that I can sit in the tank with an air
<0.5 US gal in l.9 litres, pretty much. 50 mg per 4.5 litres is what's
recommended. To be clear: that's 51 milligrams, i.e., 50 thousandths of
a gram per 4.5 litres. So by my maths that's 21 milligrams per 1.9
if you have a single, say, 100 milligram tablet, then you want about
one-fifth of that per 1.9 litre/0.5 US gallon. If the tablet was a 200
mg tablet, you'd want one-tenth. Make sense?>
Based on your book (mine has yet to be delivered. Everything takes
longer in this dang town), I believe I need to use 21 grams of metro for
half a gallon?
<Not 21 grams; 21 milligrams! That's a thousandth of that 21 grams!>
I don't have a scale so admittedly it would be guesstimated. Would you
recommend following that or using the instructions that came on the
<If all else fails, use the manufacturers instructions.>
It calls for using far less.
<I would imagine! See above.>
One tiny scoop (maybe 1/32 tsp?) per 2.5 gallons.
<Without knowing the concentration of Metronidazole in the powder you
have, or the size of the scoop supplied, it's hard to say what 'a scoop'
Thanks a bunch!
Pseudomugil luminatus (C.f. Paksai) quarantine issues
Tank setup is a 10G for breeding and a 5.5 for quarantine. The 10 is
heavily planted and has 4 species of moss, runs sponge and bio wheel and
has been established around a year. Ph is 7 +- .2. I run liquid ferts
and co2 for the plants parameters are good otherwise 0 nh, no2, and no3
TDS is 275 no fluctuations really at all temp 76. Breeder is stocked
with 2 males and 4 females, they share with a Crowntail Betta and a
cherry shrimp colony. I have 2 other males in a 40 G community nano tank
waiting for their females to arrive. Problem occurs when I get in new
stock. 3 orders now, within 48 hours of arrival I lose 50%~ of the stock
and cant figure the why especially when I get in other Pseudomugils (I
currently also have Furcatus and Gertrudea) and they have 90-100%
<Very disturbing. The first thing is to see how similar your water is to
the retailer/shipper. Set up a quarantine tank with essentially
identical water chemistry and temperature. I will note that Pseudomugil
species may often be found across a broad range of habitats, but
particular populations may come from places with quite specific water
chemistry. So a given species might be found in rivers, slightly
brackish swamps, or blackwater streams -- and the preferences for a
given breeding population would reflect the conditions they were
originally collected from (or their
parents, anyway). So check with the breeder or shipper, and act
accordingly. Once the fish are settled and surviving, you can then think
about adapting some/all of them to your main tank chemistry parameters,
presumably over the longest practical time-frame.>
The Q tank takes water directly from the 10G daily through WC along with
aged water from my holding tank it has floating plants and 2 sponge
filters, it runs 0 nh, 0 no2, and maybe 10 no3 ph again is right around
7 and TDS is steady 275. The only symptoms I can really see is that a
few hours before passing they start to hover at the surface and stop
eating, I feed quarantine the same as the 10, crushed flake and baby
brine if I have any.
<Does sound like stress.>
They will eat up until a few hours before passing just fine but then
stop accepting and just hover. Pseudomugils will spar for dominance and
that seems to be my culprit due to the other physical sign I see on the
dead fish which is small bite marks about the belly. I have yet to
witness the actual biting though so I am still unsure and I am
definitely unsure how to stop it. Once past the 48 hour mark they have a
90% survival rate and seem to do well but I have battled this issue for
the better part of a year now.
Once in my display tanks they thrive and are breeding currently.
I am getting these fish in from wholesalers via my LFS at $15 usd a pop.
I cannot in good conscience order a 4th batch until I have my mortality
<Other than water chemistry changes, do also run a copper test kit on
your water in case there's some copper in your plumbing that's shocking
the fish. Shouldn't be an issue with RO or rainwater, but certainly a
tap water. Do the surviving specimens give any clues, such as evidence
of Velvet or Whitespot?>
Any experiences or help here would be greatly appreciated. I keep
heavily planted and stocked tanks with little to no mortality because I
watch parameters closely and use quarantine as a tool but my tool is
failing me at the moment. HALP!
<Hope this helps, Neale.>
Rainbowfish disease 8/11/17
Read a post on your website by bob Fenner referring to the treatment of
In 1996 I submitted article to FAMA using Ceftin to treat this disease
It is 21 years later. I still keep rainbows
The treatment of choice is Kanamycin
Disease is gram negative Aeromonas or Aerobactor
Don't have any way to let bob Fenner or others know this
Perhaps you can pass on info
Anyone can contact me for details
Harvey Hammer, M.D.
<Thank you for sharing Harvey. Will post, Bob Fenner>
Subject: Rainbowfish disease
Inclusive of your email. B
Rainbowfish with fuzzy lips...
Hi guys, hope all is well. I have an issue with my Marcii rainbows and
I've spent countless hours searching WWM and other sites and can't
really find an answer. 2 or 3 of them have a sort of white patch on
their upper lip sometimes the bottom. Its not Columnaris because they've
always had it to a certain extent for the year I've had them. My water
parameters are good, I do bi-weekly pwc and they are in with emerald
Corys and Glowlight tetras. I also always use the same gravel vac, nets,
etc. between all of my tanks and never seen it anywhere but on these 3
fish. There are 8 other
Marcii's in the same tank that don't get it. There is no odd behavior
from these fish, they eat normally. Sometimes the white patch looks like
it has a little string or tuft floating off. There is no gill
irritation, no spots or ulcers on their bodies, they are just healthy
looking and acting fish. I'm not sure what to make of it. I was in the
process of rehoming
them but the guy didn't want to take them because he was sure it was
Columnaris and wouldn't believe they've been that way pretty much since
I got them. Im attaching photos. Can you offer me any suggestions? I
prefer not to use medications, but I will if you think its important for
the health of the fish. Thanks.
<I'm fairly certain this is physical damage, and the white tissue that
comes and goes is simply dead skin sloughing away. The question now is
how they get damaged. One explanation is fighting. Rainbows normally
fighting by swooshing water at each other while lining up side to side,
but if they're snapping at each other or wrestling with their jaws, then
mouths might be damaged. Alternatively, they're ramming into something,
and precisely this sort of damage is seen on active or nervous fish when
kept in glass boxes. A lot depends on the size of the tank, how clearly
defined the edges of the tank are with rocks or plants, and how often
the fish get spooked. The famous situation is the lights suddenly coming
on in the morning. Old school fishkeepers recommend turning the room
lights on first, then after a certain period of time, say 10 minutes,
turning the tank lights on. Make sense? Do the reverse when turning the
Aggressive or nippy fish can cause the same fright reaction, and in turn
the same trauma damage. Hope this helps, Neale.>
Re: Rainbowfish with fuzzy lips... 1/28/17
Thanks Neale! All of that makes absolute perfect sense and is completely
right on. There are 11 of them in a 55gal with both ends pretty much
uncovered. I just recently trimmed back 2 massive Amazon swords. They
never lock lips but they are very active eaters so maybe some bumping
into things. Although they aren't timid around me, I do get lazy with
lights. I'll work on that. Thanks again, you guys are the best!
<Glad to have helped, and good luck! Neale.>
My Australian rainbow fish have large white bumps or clumps on fins. Fin is
almost gone. One fish with the worst bumps now swimming vertical most of the
time. Not sure what it is.
<Mmm; a few possibilities; none of them "good". "Micro" Sporidean likely...
an as yet incurable protozoan issue. Rainbows and a few other groups of
fishes are especially susceptible... CAN only be avoided; by "good genetic
background", suitable environment, "good nutrition. I would
destroy/euthanize this specimen... NOT allow it at least to be housed with
other Melanotaeniids. Please see Neale's piece here on WWM:
Dwarf Rainbowfish wart 9/25/16
Hello, crew, I hope you are doing well.
<Thank you Robert>
Along with this email I have included three pictures of a female (?) dwarf
Rainbowfish with a strange growth on its side. It started as a small red
point a few days ago and has growth about 4x since then and also has a small
white patch in the center (not very visible in the pics). at the other side,
it has a small white growth which makes me believe it is some kind of
worm... while the other wart-like growth reminds me of having read of
Lymphocystis... The fish is 1.5 years old (or at least the times its been
I hope you can help me identify this problem. The fish is eating and its
behavior doesn't seem to have changed at all.
<Have encountered similar growths on Rainbows over the years; mostly
anomalous as to cause/etiology. Many times rapid onset; with the loss of the
specimen. Melanotaeniids appear/are more sensitive to environmental
stressors that many other families of freshwater fishes.>
Tank is a 150 gal community, ph of 7.4, dGH of 10 and dKH of 9. Temp is 28
C. Tested for nitrogen, readings are 0,0,0 (heavily planted tank, high
tech.. no water dosing only substrate so the tank stays pretty much nitrate
Thank you, for your time. I hope you can help me. I have isolated her to a 5
gal with cycled filter media, temp is 25 C, dGH and dKH are the same, but ph
is 7.9 (the high tech has co2 injection, which reduces the ph a bit).
<I would remove this one individual, treat elsewhere... with? Perhaps an
Anthelminthic like Prazi... but also w/ Metronidazole/Flagyl, per the S.O.P.
archived on WWM. IF the specimen perishes, I'd preserve it, or seek out help
in dissecting it to try and disclose the issue here. Bob Fenner>