FAQs on the Molly Health/Disease 6
Articles: Mollies, & Poeciliids: Guppies, Platies, Swordtails,
Mollies by Neale Monks, Livebearing
Fishes by Bob Fenner,
FAQs on Molly Disease:
Molly Disease 1,
Molly Disease 2,
Molly Disease 3,
Molly Disease 4,
Molly Disease 5,
Molly Health 6,
Molly Health 7,
Molly Health 8, Molly Health ,
FAQs on Molly Disease by Category:
Nutritional (e.g. HLLE),
Social, Infectious (Virus, Bacterial, Fungal),
Parasitic (Ich, Velvet...),
FAQs on Molly Reproduction/Breeding:
1, Molly Reproduction 2,
Molly Reproduction 3,
I have 14 tanks ranging from 5 to 55 gallons mostly Acrylic and mostly
containing fresh water native species. Bluegill, Blue spots, Orange
spots, Longears with a couple of tanks of Rosies.
<Sounds fun! Not a big fan of 5-gallon tanks so far as fish are
but a 55-gallon tank full of native fish would be a treat!>
A week ago I bought 8 Mollie from a petstore to put in a 30 gallon
SeaClear eclipse tank that I had cycled with 3 (healthy) goldfish. The
tank has the specified amount of Aquarium salt
<By what do you mean "specified amount"? And is this plain
vanilla aquarium salt, or actual marine mix? Let's be clear on
this: Mollies do best in hard, basic, slightly saline water. Aquarium
salt does little/nothing about hardness and pH, so if you have soft
water, adding aquarium salt merely turns it into salty soft water.
Marine salt mix contains mineral salts that raise pH and hardness, so
works great with Mollies. I recommend between 5-9 grammes per litre,
depending on how hard your water is and how much nitrate there is in
the water. In soft water, or water with more than a trace of nitrate,
use higher amounts (sodium chloride detoxifies nitrate, and this is
very beneficial to Mollies which are super-sensitive to
and I added a couple of very small well washed seashells as per advice
from a book I have. I test the tank every other day and it has remained
consistent. it has a 50 gallon HOB filter, a 30 gallon air pump with 7
inch wands at each end of the tank and a Jager 100 watt heater. The
tank temp is steady at 78 degrees, the PH is 7.5 and the water is
toward the alkaline side. The nitrates are fine.
<As in zero?>
I bought 2 silver Lyretails, 2 gold Lyretails, 2 Dalmatian Lyretails
and 2 regular Black Mollies. They came out of 4 different tanks at the
I requested all females. By evening I knew one of the Gold Lyretails
was sick. It went to the top of the tank and there it stayed.
<Do review temperature (which should be fairly high, 25-30 C), pH
(which should be stable and around 7.5 to 8), and hardness (which
should be at least 15 degrees dH). Salinity is something there are
endless arguments over, but suffice it to say that Mollies *always* do
well in slightly brackish water, even if they *sometimes* do fine in
freshwater. This is especially true when water conditions are less than
perfect in other regards. Use marine salt mix (plain aquarium salt is a
false economy) and dose at 5 to 9 grammes per litre (SG 1.002 to 1.005
at 25 degrees C). I'm using metric units here because that's
what I learned at university doing marine biology. It's an
especially convenient approach too since one level teaspoon is about 6
grammes, so adding one level teaspoon per litre is a very easy approach
to take if you're aiming for SG 1.003 at 25 C. But if you want to
use Imperial units and compare them against changes in water
temperature, you can download Brack Calc from my web site and make the
conversions yourself. What you'll quickly discover is these
"teaspoon per gallon" amounts often mentioned among aquarists
are hopelessly low.>
The next morning it was dead on the bottom I took it back to the
petstore only to discover that the tank it had come from now contained
another dead Gold Lyretail as well. This being the case I opted for an
exchange of another Dalmatian. The salesperson at the petstore gave me
a hard time insisting that they needed a water sample other that the
one the dead fish was in but relented and gave me the replacement. At
this point I now have a bag in my refrigerator with 1 black Molly, the
second gold Lyretail, & one of the silver Mollies. I have one of
the original Dalmatians in a hospital tank and don't know if it is
going to survive or not. I now know that you should NEVER put new
fish from different tanks in the same tank. The Gold Lyretail infected
the other fish and at this point I may well lose them all.
<Honestly don't think this is anything contagious. Yes, Mollies
can come down with certain infectious diseases like Ick and Camallanus
worms, but most Mollies die because of environmental issues.
NOT community fish and they are NOT easy to keep and they are ARGUABLY
NOT even freshwater fish (at least, fish for freshwater aquaria). The
odd thing is that they're common as anything in freshwater
habitats, but for whatever reason they do not do consistently well in
freshwater aquaria. Various factors have been suggested for this; read
By default, Mollies should be kept in slightly brackish conditions.
They don't need a lot of marine salt mix, so keeping them thus is
inexpensive and easier than messing about with pH and hardness levels
using other techniques. Many plants will thrive in such conditions, so
such tanks aren't difficult to decorate. All things considered,
keeping Mollies in a slightly brackish aquarium is a
My only question at this point has to do with aggression.
<Yes, they are aggressive.>
All of these fish were supposed to be female but the larger Dalmatian
that is still in the 30 gallon SeaClear consistently attacks the
remaining Silver Molly and the other Dalmatian (the replacement for the
Gold Lyretail} which has the regular tail. It ignores the smaller Black
Is this normal behavior for a female fish or is it more than likely a
<Generally males are aggressive to some degree. Keep two or more
females per male. They ignore species or variety differences, and a
male Molly will chase any female Molly in range: Black Molly, Balloon
Molly, Sailfin Molly, whatever...>
It is the largest fish of the 8, is fat and round and looking at its
fins appears to be a female but I'm no expert.
<Should be easy to tell. Males have a crooked, tube-like anal fin
very different to the triangular anal fin of the females. Females tend
to be bigger and somewhat rounder as well.>
At this point I am beginning to feel I have been mislead about
<Almost certainly the case. But "mislead" is perhaps not
the right word here. Every aquarium book written will state in no
uncertain terms that Mollies are tricky fish that do best in slightly
brackish conditions. The fact people are told by retailers that
they're community fish that do fine in freshwater tanks says more
about being cautious about salespeople tell you than anything else. I
wouldn't trust a sales clerk to recommend me a pair of trousers or
a new car, and neither would I trust them on a particular fish being
suitable for my home aquarium.>
So far they are 10 times more difficult than my Sunfish (which are
supposed to be difficult) from every standpoint.
<I'd agree with this, and have often made the point here that
Mollies aren't easy fish.>
I was lead to believe Mollies are peaceful and easy to care for. I have
had a wild caught (with a hook no less) male bluegill for 6 months now
in a 55 gallon tank (moving him to a 120 because he is getting to big
to turn around in the 55) that eats out of my hand and is healthier
that I am. I have raised Blue Spots and Orange spots from fry and not
lost a one while these Mollies are dropping like flies and I DO take
care of my Tanks. I am disabled, at home 24 seven and monitor them
<If you don't already have "North American Native Fishes
for the Home Aquarium" by David Schleser, you really owe it to
yourself to track down a copy. Besides covering lots of material I
suspect you'll enjoy, it includes details on maintaining the North
American species of Molly as well. So you'd find that part of the
book very useful. You can mail-order wild Poecilia latipinna from
biological supply houses, and these native species would probably
appeal to you greatly. They're bigger and very impressive animals,
even though (thankfully, in my opinion) they lack the bright colours of
Re: Molly troubles
Thanks for the FASSSST response it was really appreciated!
<Happy to help.>
The 5 gallon tank is home to Daphnia, I have 2 10 gallon glass tanks 1
is a hospital tank and the other is a fry tank. As for the specified
amount of salt I added 1 teaspoon per gallon & Nitrate is ZERO.
<One teaspoon of tonic/aquarium salt per gallon isn't enough. Do
read my message, and understand why you're adding salt. Sodium
chloride by itself has some value in detoxifying nitrite and nitrate,
but it doesn't raise pH and hardness. Marine salt mix at the dose
stated, roughly one teaspoon (6 grammes) per litre (0.26 US gal.) will
raise hardness, carbonate hardness, and pH very effectively. While some
people try to keep Mollies with less salt, or using just tonic/aquarium
salt, the bottom line is they often don't do well under such
conditions, so I find that a bit of a pointless approach. Much better
to take Mollies for what they are, and provide conditions that suit
them consistently well.>
I have read that crushed coral added to the substrate is beneficial and
I do have several large pieces of coral that came out of a saltwater
tank, should I follow this advise and add it or not?
<Adding crushed coral in an undergravel filter will help harden the
water and raise the pH. Simply dumping some crushed coral into a tank
without an undergravel filter will have little effect. Think about how
Crushed coral dissolves into water that is drawn past it. In an system
with an undergravel filter, there is a constant flow of water, so the
coral and the water are constantly reacting with each other. In a tank
without an undergravel filter, only the very top layer of substrate
meets a moving flow of water; once you get a millimetre or two into the
substrate, water flow slows down to practically zero. Hence the amount
of reaction between the water and the crushed coral is tiny. If you
don't have an undergravel filter, the better approach is to put the
crushed coral in a media bag, and throw that into one of the
compartments in an canister filter. If that isn't an option, adding
either marine salt mix or a Rift Valley salt mix (if you don't want
to raise salinity) is the best way forward. Do read here:
I have ordered the book you recommended and can't wait to get
Also as to the wild native species could you be a bit more specific
about where I might find them
<This isn't a recommendation by any means, but one of the shops
I have bookmarked is Sachs Aquaculture, here:
If you look at their Freshwater and Brackish water vertebrates pages,
they have a bunch of cool livebearers and killifish that might appeal.
I'm sure a little time spent on Google will reveal other, similar
retailers. Clubs like the American Livebearer Association might also be
good sources of information with regard to where native livebearers
might be purchased.>
The bright colors don't mean a thing to me.
<I guessed as much, and I suspect you'll enjoy the book I
mentioned as well as some of the other species you'll read about in
there. Coldwater fishkeeping is a much neglected part of the
If it did I wouldn't have so many Sunfish some of which are pretty
plain Jane but I really like their "personalities."
<As do I.>
I may have missed it but is it common for the female Dalmatian Molly to
be so mean?
<Not common, but happens. Keeping in bigger groups should help,
though Bob often recommends taking aggressive fish out of the tank for
a few hours, and then returning it. With any luck, that'll
"reset" the hierarchy, and the bully won't be so
I am about ready to give her away (with the info of course that she
needs to be isolated for two reasons)
Re: Mollies troubles --
As I am disabled and don't drive anymore I have to wait until
someone can take me anywhere to buy Aquarium items or order via the
internet. I have a new unopened bottle of Seachem Marine Buffer is this
of any use for my Molly tank?
<Certainly can be used. I'd start with about a half dose though,
and see how things go. That should stabilise the pH between 7.6 and
8.0, which would be an ideal range for Mollies.>
It is written on the front that it safely raises & maintains ph to
8.3 and that even if more than the prescribed dosage is added it will
not raise the ph above 8.3.
<This is indeed how buffers work.>
It also states that the prescribed dose will raise the alkalinity by
about 1 meg/L. I realize this product is for a saltwater Aquarium so
this is probably a stupid question but I have the stuff so would like
to know if I
can use it to advantage for my Mollies or if it would be harmful or
<Can be used in freshwater and brackish water tanks safely. Make any
water chemistry changes gradual though. I'd work out how much you
need in millilitres or drops or whatever, and add one-quarter that
amount on day 1, another quarter on day 2, and so on. This will allow
your fish and the filter bacteria time to adjust. You can also look out
for any unusual behaviours that might suggest stress.>
Thanks Again for you help.
Re: Molly Spinning, Upside Down
Swimming, Exophthalmia & Other Bizarre Symptoms,
I'm checking water before every change to see if it has gotten
I'm using an API liquid/test tube kit for ammonia and a Jungle Labs
Quick Dip strip for nitrates, nitrites, GH, chlorine, KH, pH.
<I'm not a fan of the dip strips but they are probably fine
Everything looks fine, definitely no ammonia problems. If it has
changed at all, it is not discernible - still looks like 0 ppm.
Nitrites are still 0 and Nitrates are <20. A small amount of algae
has begun to grow again. I'm not sure he's eating but then
he's probably not producing waste. I have not vacuumed gravel (too
stressful). I guess with only one fish and very little food, water has
managed to stay okay. Temp is about 77-78 degrees.
Is it possible there are other things in the water that would (over 8
months) cause problems and then, seemingly all of a sudden, sicken the
Molly and cause all of those strange symptoms - I'm mean corkscrew
and upside down swimming was pretty bizarre to me?
<Well, in captivity mollies do pretty poorly in fresh water, but are
nearly bullet proof in brackish, so that may be a partial factor
I only test for the basics. I use well water and "spring"
water in just about equal parts.
Our tap water is softened so the readings are: GH - Very Soft, KH -
High, and pH - Alkaline. Our well water is: GH - Very Hard, KH - High,
and pH - Alkaline. I was buying "spring" water to drink and
GH - Very Soft, KH - Low, pH - Acidic. I gathered an approximate
combination of well and "spring" water, about equal parts or
a little more spring, would be about right for livebearers. I expected
a moderate level of bi-carbonates and carbonates and the right GH and
KH and pH. I seem to remember reading that my fish would be okay with a
pH of 7.5.
<For the most part live bears like harder water with a bit higher
pH, but 7.5 is generally acceptable. Sounds like your tap water may be
perfect alone for livebearers.>
I always added water conditioner (no chlorine, but thought it
wouldn't hurt) and aquarium salt pretty much as a
"tonic"; didn't really realize at the time that Mollies
like brackish water.
<I would probably forget about the aquarium salt, not really doing
Indeed my water has been very stable over the months. I got ever so
slight white, crusty build up on the filter intake. And I did get a
slight brown algae growth each week. I would brush sides of tank at
water change time. I changed the carbon filter about every 4 weeks.
The well water is very hard. I'm told there is a great deal of
limestone in this area, but I've never heard that there are other
troubling (to humans anyway) hard things. I don't know if we will
continue fish keeping but I am curious about further tests that can be
done on water (especially since that seems to be the biggest issue -
actually I'm not sure if it's water that's the problem or
changing the water that's the problem - I'll just have you know
that I was diligent, every week whether I liked it or not!).
<I think ultimately the medications proved worst than the cure,
I'm thinking that the current symptoms are likely the result of the
Are there other test
kits that would give better info. or would a one time test of the well
water answer that question?
<Not really, you hit most all the tests available that would be
I just noticed I'm writing past tense - but he is still hanging in
there. I guess I just can't help but think the poor Platy is
Can I just tell you that this is so frustrating? I'll keep doing
water changes but the only reason it's not overwhelmingly tempting
to intervene and do chemotherapy is that I don't know what to give
him because I can't diagnose what's wrong.
<Given good water quality fish can be surprisingly resilient, and
what I would do here. A little Methylene blue may help here, but I
would not try anything stronger. Best bet here in my opinion is to
maintain the water quality, try to get the fish to eat, and hope for
Re: Molly Spinning, Upside Down
Swimming, Exophthalmia & Other Bizarre Symptoms
The Platy died as expected. Thanks for your input. Even
"good" water doesn't mean your fish will be healthy and
disease free. A tough lesson after diligently doing all the things
necessary to get the water and keep the water in the best condition
<Sorry to hear, better luck in the future.>
Molly Spinning, Upside Down
Swimming, Exophthalmia & Other Bizarre Symptoms
Here are some stats of my aquarium:
10 gal tank
nitrate < 20
about 8 months old
KH about 150 - 180
weekly water changes of about 20-30% conditioner and aquarium salt
added to water used in changes gravel vacuum every other water change
water readings after initial cycling have been very stable except for
nitrite which was initially 0 then gradually showed slightly pink
(<20)only one black molly and one red wag platy (only 3 fish to
start but one female died after birthing)
<Ultimately this tank is too small to keep mollies long term, which
also do best in brackish conditions in captivity. In fact in brackish
water mollies are almost indestructible.>
My question involves disease (no big surprise). Molly's tail looked
"thin", like some of the tissue had come off; it was probably
like this when purchased; went unnoticed until dorsal fin got a split
down the middle; treated with Victoria green, Acriflavine (Fungus
Cure), one dose, and Minocycline (Maracyn II) and erythromycin
(Maracyn), one five day treatment of both. Fin grew back together from
bottom up; tail somewhat better; no other noticeable symptoms. Platy
had no symptoms. Three months later, noticed about two weeks of Molly
darting at the top of tank, then same thing with his tail and dorsal.
Intended to give same treatment but failed to give Victoria green and
Acriflavine; gave only Minocycline and erythromycin. Fifth day of
treatment, dorsal fin growing back together, tail looking a bit better.
First day after treatment, Molly began this series of symptoms in
chronological order: swimming fast, up and down, then spinning while
swimming, corkscrew fashion, still trying to eat, no signs of normal
bowels movements, then curvature in spine, then exophthalmia beginning,
then a little difficulty in getting to top, not eating, then curvature
seemed to go away, then swimming upside down solely, then listing but
swimming more upright with some spinning, gulping, fins becoming
ragged, exophthalmia severe in both eyes, then lying on side on gravel,
then mouth protruding (or insides protruding out). No signs during this
time of any fungus, external parasites. But since common things are
common, I did the following in this order (obviously at first signs of
illness): checked water, temp, filter - all things seemed normal, fed
shelled peas and blanched romaine, removed filter media, gave Victoria
green and Acriflavine (Fungus Cure), one dose, then Praziquantel,
Diflubenzuron, Metronidazole, Acriflavine (Parasite Clear) one dose,
then later started Minocycline (Maracyn II) treatment. Only about 24
hours between medications. I realize I could have killed the Molly with
medication, but he was really bad off, and I was starting to feel even
more helpless. I guess I expected 12 -24 hours of treatment to make
some difference if I was using the correct meds.
Anyway, the whole thing from the fast swimming forward took about 6
days, then he died.
<Could be a reaction to the medications, could be "Whirling
disease", an infection caused by the parasite Myxobolus,
especially if you feed your fish Tubifex worms. First guess would be
water quality and reaction to the various medications.>
Now the Platy is shimmying, and may have a few other subtle changes in
behavior. Obviously there are still medications in the water, probably
all of the above mentioned. The water parameters are still okay but I
suspect the biological filter may be affected soon. I guess different
fishes mean different symptoms but surely the Platy is being affected
by exactly the same culprit. So, my questions are: 1) what is sickening
my fish and should I proceed with Maracyn II treatment and/or something
<I would stop all treatments at this point and do lots of water
changes and see if that helps.>
and 2) what should I do about the biological filter - add a product or
can I recycle an existing tank
<Allow it to recycle.>
and 3) what other tests are available for water, meaning what other
things could be in the water that would negatively affect the fish over
8 months that I can test for (since water quality is noted as being the
most likely cause of problems)?
<My first guess is the Victoria Green, aka Malachite Green, pretty
toxic stuff. Combined with the other medications it could do a real
number on the fish.>
Although I'm beginning to feel that a hobby that involves periodic
death is not for me, I must do what I can for this remaining fish. (I
also realize he doesn't want to be alone but until he is better
he's going solo).
<Best move, more fish just complicate things. To be honest with
mollies and Platies to a lesser degree, first thing to do is add a bit
of marine salt, brackish conditions seem to do marvels for these fish
Sorry for such a long message. Thank you for your time.
Re: Molly Spinning, Upside Down
Swimming, Exophthalmia & Other Bizarre Symptoms
Thanks for the information. I actually had fed them a few blood
<Store bought frozen or freeze-dried blood worms are generally very
safe, it is Tubifex worms that should be avoided due to their ability
to transfer disease.>
The Molly was the eager, and therefore, fast eater. I accidentally let
about 7-8 worms get in the tank, which looks like such a small amount,
but I didn't feed them the worms often and usually just 2 or so
fish (in place of regular food).
<Perfectly fine, my mollies eat blood worms regularly.>
The Molly probably ate them all or most (which is why I thought of
constipation and gave veggies).
<Actually blood worms are pretty good at preventing
But I've had this food for the whole time I've had the tank and
it has never seemed to affect them negatively. Is it possible, that
this food contained a "bad bug"? It is Hikari Bio-Pure FD
"100% Pure Freeze Dried" blood worms with vitamins.
<Unlikely, blood worms are very safe and not carriers of disease as
Tubifex can be. I think we are dealing with reactions to medications
Re: Molly Spinning, Upside Down
Swimming, Exophthalmia & Other Bizarre Symptoms
I stopped the meds when you recommended. The shimmying in the Platy
stopped, but then he began staying very still, sitting on the gravel.
His tail and dorsal are changing, black near the body (normally black -
he's a Red Wag Platy), then brownish as it moves outward, and then
pale, almost clear and slightly frayed on the
outermost edges. After ceasing meds, I put filter in and increased
water changes to 20% every 12 hours or so (water parameters are still
<Are you sure? Sounds like ammonia poisoning is what is possibly
Now, he may be moving a bit more, tail and fins still look unhealthy,
and his eyes look like they are clouding over and may be protruding
slightly. I'm not sure, but it looks like he may be bumping into
the plants and sides of the tank.
Any more suggestions?
<Keep up the water changes and run some activated carbon.
Double-check you water parameters because it sounds like there may be a
Dalmatian Molly Sitting at
Bottom of Tank (ammonia, no salt, the usual...) 8/8/09
My apologies up front for what are likely some basic questions, but I
just got a new tank a little over 4 weeks ago and the thing didn't
come with an idiot's guide to setting up and caring for an aquarium
and the fish in them.
<We consistently suggest you buy (or borrow) a book before anything
Sure, you miss out on immediate gratification, but sometimes learning
about a subject before you dive into can make all the
Most of my problem stems from the fact that every person I ask at
PetSmart has a different answer - and none of them seem to be
<Indeed. Here are some thoughts on selecting livestock for the first
I have a 29-gallon tank with 2 Neons, 2 guppies, 1 Mickey mouse platy,
and a Dalmatian molly. I was waiting to populate the tank more until
the tank had stabilized.
<Mollies are, essentially, incompatible with most other community
Platies and Guppies happen to be livebearers and will tolerate slight
salinity well, but the Neons won't. Do read here:
If you want Mollies, you should add a little marine salt mix -- not
aquarium or tonic salt -- to the water. This steadies a basic pH, adds
some carbonate hardness, and increases the salinity, and all three of
things are helpful with Mollies.>
I woke up this morning to find the molly sitting at the bottom of the
tank - an occasional move of the fins or shifting on the rocks, but
otherwise, just sitting there. When I fed the fish this morning, the
the one eating far more than its share) just stayed along the bottom
and ignored the food. I don't see any of the fungal disease signs
mentioned in the other FAQs, though I suspect water quality is the
<So do I.>
When I got the tank, I was told to change 30% of the water once a
So just shy of one month in, I brought in a vial of water to PetSmart
to have it tested and found out the ammonia levels were not toxic, but
pretty darn close.
<Hmm... ammonia is toxic at any level other than zero, end of story,
so if the PetSmart clerk said the level was above zero but not
dangerous, he/she was either lying or ignorant. Mollies are especially
sensitive to ammonia when kept in freshwater tanks.>
I was told to change 30-40% of the water and that should take care of
the problem. I did so by vacuuming the gravel and took the water to be
tested again several days later. The pH levels were too high and the
ammonia hadn't dropped at all. They gave me a pH decrease and
ammonia remover and told me to change the water again and add
<This clerk is having a laugh at your expense. Ammonia is a basic
substance, i.e., it raises the pH. So long as you have non-zero ammonia
levels, you'll have a pH higher than it would be without
Furthermore, Platies, Mollies, and Guppies all want a basic pH, around
7.5 to 8.2.>
I did that and took yet another vial in a few days later. The pH had
balanced, but the ammonia was still too high - and this person told me
the pH decrease and ammonia remover were worthless. This person told me
to change the water again and add stress coat. I did - and ended up
changing about 50% of the water. Took another vial in this morning
after seeing the molly at the bottom of the tank and was told that the
ammonia levels were still too high (I think they were around 3?).
<3 mg/l is very toxic. If 0.3 mg/l, that's a typical background
level to see in an immature aquarium. In the short term, this is likely
to trigger Finrot and Fungal infections, even if it won't
immediately kill your fish.>
They told me to not change the water for a week because the molly is
likely stressed out from all the water changes (3 in the last 10
They told me to add more stress coat today and change 25% of the water
in one week's time. I added the stress coat. They also told me I
was likely overfeeding the fish - two times a day. They said to feed
them only one time every other day - sounds like very little to me.
<Whilst maturing a tank, feeding every other day is about
Not a one of them suggested that the molly would do well with a little
salt in the water - so there's none in there.
So here are my questions. Do you suspect that it is a water quality
Should I wait a week to change the water or is the "fish is
stressed out" theory incorrect?
<No, don't wait. The theory is rubbish. Do regular 10-20% water
changes, daily if necessary, to keep ammonia and nitrite as low as
possible through the cycling phase.>
Can you change the water too often?
<Provided pH and hardness and temperature are the same in the new
water as the aquarium, no. In practise, for a tank being matured,
changing around 20% every day or two is an extremely good idea. After
3-4 weeks, the tank should be cycled, or pretty darn close, and you can
fall back to the usual 25% per week.>
Should I add some salt or will that impact the other fish
<Remove the Neons to another aquarium, and then add 3-5 grammes of
marine salt mix (the stuff used in marine tanks) per litre of
They told me to change the filter at the time of my first water change
- which I did. Did I lose some or all of the good bacteria in the tank
in the process?
<The filter bacteria are in the biological filter media, typically
sponges or ceramic media. These should be rinsed in a bucket of water
taken from the aquarium during a water change. Clean these every 4-6
weeks, more often if the filter gets clogged easily. Chemical media,
things like carbon, if used, should be replaced once a month;
there's no point cleaning them.>
How often would you feed them?
<Initially every couple of days is fine. Once the tank is cycled and
ammonia and nitrite are zero, feeding a small pinch daily should be
Since I can't get a straight answer out of the PetSmart people,
should I invest in my own water testing strips and the internet for
<I know it's heresy in this lazy age of instant information, but
books are what you want. Books are written by experts (people like me!)
and edited professionally to make sure the facts presented are
reliable. Your public library will have a selection of books on
fishkeeping, even if you don't want to part with the $10 required
to buy one. Failing that, WWM has lots of detailed articles on every
imaginable aspect of the hobby.>
Where can I find that idiot's guide to keeping your fish
Sorry for all the questions. I've been on the web a good chunk of
the evening trying to figure out what's wrong with the molly and
this site seemed to be the most informative and helpful. Seemed the
right place to
unload all my "help, I'm a rookie" questions!
Thank you for your time and help. I'm really hoping to get that
molly back up and swimming about...
<Once provided with clean, slightly salty water it should pep
Re Dalmatian Molly Sitting at
Bottom of Tank (ammonia, no salt, the usual...) 8/8/09
<Wasn't clear with this answer...>
Should I wait a week to change the water or is the "fish is
stressed out" theory incorrect?
<No, don't wait. The theory is rubbish. Do regular 10-20% water
changes, daily if necessary, to keep ammonia and nitrite as low as
possible through the cycling phase.>
Re: Dalmatian Molly Sitting at
Bottom of Tank (ammonia, no salt, the usual...) [RMF, please edit the
Daily] <?> 8/10/09
<<Neale: What does
this mean? BobF>>
Hi Neale -
Thank you very much for all your helpful advice.
<Happy to help.>
I went in and changed a little over a quarter of the water with a
(hopefully) very thorough gravel clean and the water is looking a whole
lot clearer. I'll keep doing daily or every other day 10% water
things stabilize and add a little marine salt once I'm able to get
the Neons out of there.
<Very good plan.>
We'll see how things go, but regardless, the molly was swimming
around this morning and seemed much more active. Thanks again!
<Yes, Mollies often respond quickly to beneficial changes in their
environment. This is the flip side to the point made last time about
how badly they react when kept inappropriately.>
Mollies sick, can't figure
out what the problem might be. -- 08/04/09
Hi and thanks in advance for your help. We have had three Sailfin
mollies for several months (1 M and 2 F). They have been terrific pets
and are usually very energetic. However a few days ago we noticed that
our male and youngest female have been acting very sluggish, almost
tired. the male has been found hanging upside-down in a plant twice and
both have been spending a lot of time resting on the bottom of the
tank. Suspecting that it was a water quality issue, we tested for
Ammonia, Nitrites, and Nitrates and found 0 Ammonia, 0 Nitrites, and
Nitrates came in between 10 and 15 ppm. We did a 10 gal. water change
anyway (29 gal tank) to make sure the water conditions weren't the
problem. Otherwise the conditions in the tank should also be as
favorable as they can for mollies in a freshwater aquarium. Alkalinity
is over 8.0 and GH is 20 dH. Even after the water was changed their
behavior remained the same. We moved the two mollies into a quarantine
tank with higher salt content until we can figure out what is going on.
They are both still eating, and they both seem to be moving around a
bit more, but they are still not right. Any ideas as to what the issue
could be? Other aquarium inhabitants include a handful of Cardinal
tetras and Rummynose tetras, two Platies, two Chinese algae eaters, and
one male Swordtail (our two females both passed away after
Mike & Kari
<Hello Mike and Kari. The reality is that Mollies often don't do
well in freshwater tanks, period, end of discussion. So assuming you
have good water quality, the right temperature (a little on the warm
side, around 26-28 C), and you're offering them a greens-based
diet, then they should be in good health. The lack of brackish water
conditions is really all that's left.
I don't recommend Mollies as community fish, and don't advise
people to buy them except in situations where creating brackish water
conditions is an option. Cheers, Neale.>
2 mollies-one sick the other
Hi, I've been reading all your comments on mollies but couldn't
find the answer I was looking for.
<Oh? Well, let's see...>
I have two mollies, one black and one orange. I'm sorry I don't
know what kind exactly, just that the black is male and the orange is
female and pregnant for the second time. We bought them 28 days ago and
the first night we had them, she gave birth to 7-10 babies. We found
them in the morning and I took the male out because he was chasing
<Keep more adult females than males; as I'm sure you read here
at WWM as well as in most any aquarium book, you should buy one male to
each two (or more) females, otherwise the females will be harassed by
the males. Males are "programmed" to constantly try and mate
with anything, and if there's only a single female, she'll be
constantly chased, nipped and inseminated, whether she wants this or
My husband crushed some flakes for them and one was going up and
eating, so I thought they would be okay. The momma molly was relaxed
now that the male was out. She was swimming all over the place before I
took him out.
After work, I saw that the babies had all died as they were all on the
bottom of the aquarium. I know now that the new water must have been
the cause. The two mollies are in a 10 gallon tank,
<Far, far too small for Mollies. You need at least a 20 gallon
"long" tank and realistically 30 gallons.>
with no chlorine (we have a well), good ph steady at 7 and low
<Nothing "good" about this; Mollies need hard, alkaline
water, preferably with a bit of marine salt mix added, since they do
better in brackish water. Aim for pH 7.5 to 8, 15+ degrees dH, a
temperature of 26-28 C, and around 6-9 grammes of marine salt mix added
per litre of water. Do all these things, and keep them in a bigger
tank, and you should find Mollies quite easy to keep.>
I have a mini Penguin Bio-wheel filter system. I did a 25% change of
the water three days ago. The fish were doing well until yesterday when
the black molly started going up a lot and "catching his
Now he stays on the bottom on his side, moving a little because he
changes places but looks dead (he's still breathing).
I think we fed them too much lately, because the female being pregnant,
is always going up to see if there's food as soon as she sees us
close to the aquarium. My husband said that they should have more food
because of her reaction. We were feeding once a day in the morning and
the last two days, we have been giving food in the morning and at
night. Also, they might be stressed; I wanted to separate the male from
the female before she has her babies, so I took him out, and put him in
a fishbowl, with some of the water from the aquarium.
<Argh! No, no, no... moving fish about, even if your intentions were
good, will cause problems of all kinds. For one thing, Mollies are
stressed by poor water quality and low temperatures, both problems with
bowls. For reasons too tedious to recount yet again, fish bowls are
useless and totally unsuitable for keeping fish in.>
As soon as he was out, the female started to look for him and was
swimming all over the aquarium.
<No, she wasn't looking for him.>
I thought she would calm down after a few minutes but she didn't. I
didn't want to stress her so I put him back. She calm down right
after she found him and was following his every move for a while. It
was funny to see.
<I think you're anthropomorphising here.>
He kept to the bottom and hide in the plants (plastic by the way). I
was wondering if he was sick and if he would get better soon or should
I take him out and quarantine. If so, what do I do about my female who
can't live without him? I just (today) added a tablespoon of marine
salt because I did that the first time I put them in a month ago. I
read that the salt might help. I have fungal meds but do not think it
is fungus because he has no white stuff on him. Could it be he just ate
too much and will be better in a couple of days?
We will go back to feeding once a day but tomorrow they are not getting
any food. Is this bad for the pregnant female? We plan on separating
the two mollies from the fry as soon as they are born by putting a
Plexiglas with tiny wholes in it, in the middle of the aquarium. Is
this good? I'm sorry for the long message but I wanted to give as
much details as possible to anyone with a similar problem as mine. We
are new to mollies but did have a couple of goldfish and a sucker a few
years ago, at our first house. (We didn't have good water at that
<Goldfish and "sucker fish" (by which you presumably mean
a Pterygoplichthys catfish of some sort) aren't compatible, and if
they died, given how hardy they are, I sincerely doubt it was the fact
the water was bad. Do please read about what fish need before buying
them; your experiences here with Mollies are all avoidable and
absolutely classic mistakes that people do when they haven't read a
darn thing about them.
While I'm happy to help, this is like the third sick Molly question
of the day, and there's another in the inbox still to be done. So
try reading, and then act accordingly:
Hope this helps.>
Anyway, thanks for your help! Nicole
Very Sick Black Molly... 7/9/09
I've heard good things about your site and it has very
helpful advice, so I was hoping maybe I'd find help here.
I have a 20 gal. tank occupied by the fry (around a year old?) of
one of my past mollies. There aren't more then ten in the
tank. Recently my sister noticed one of the black mollies, a
female (if it matters) has some sort of bubble-like protrusion
coming out of its side. The bubble is mostly clear, with some
pink in it. It actually almost looks to be coming out of the
anus, or somewhere near there, like maybe some of its organs are
leaking out (can this happen?).
<Certainly the area around the vent can become prolapsed, yes,
and this is usually not treatable directly. If the fish is
otherwise healthy and eating, the treating with a systemic
antibiotics such as Maracyn may help fix the bacterial infection
that caused the prolapse, and the addition of Epsom salt at 2-3
teaspoons per US gallon can relieve the swelling a bit (but by
itself it isn't a treatment!). Sometimes Protozoans are to
blame, in which case something like Flagyl (Metronidazole) will
be needed. Since this also treats some bacteria, you might prefer
to use this one first, and see what happens. Otherwise, if
treatment doesn't help or isn't possible, euthanise the
All the other fish are fine, are sporting no such bubbles, and
are eating normally, etc. I looked everywhere and found nothing
on the internet that sounds similar to this, and every time I
found someone mentioning bubbles on their mollies everyone
assured them it was Ick. I've treated Ick, and this is not
Ick. Could it have something to do with the fact that these
mollies are all breeding rather young?
We have nowhere else to put them and can't stop them from
Recently we removed all the fry we could (and placed them in some
of our other tanks) to reduce the population. I once knew a woman
(a former neighbor of mine, quite a while back) who had so many
children so close together that her uterus literally fell out.
Could this happen to a molly?
Or is it something water-related? I could test my water if
you'd like to know the results.
<Most fish health problems are indeed water quality/chemistry
related, so this info is always helpful. Just to recap, Mollies
need hard, alkaline water with a high temperature and preferably
some marine salt mix added; aim for a temperature of 26-28 C, pH
7.5-8, 15+ degrees dH, and about 6-9 grammes of marine salt mix
added per litre.
Nitrate is particularly toxic to mollies, so apart from the usual
0 ammonia and 0 nitrite, under freshwater conditions at least,
you want nitrate levels of less than 20 mg/l.>
I just find it odd that both our white and black mollies had fry
and yet only the black ones seem to be dying. The black mother
died a few weeks after we bought her, but the white mother lived
for a few years. Do fish pass things like this on genetically
(i.e. health problems, weaknesses)?
That being said, I've never seen anything like this before
(but I have only been a fish owner for a little over two years).
One more thing, if you'd like I could get a picture of the
fish (I'd just have to shrink it down a bit, our camera takes
<Please feel free to send along such a photo.>
And if you require any other info, please let me know and
I'll be happy to send it right along. Thanks so much for
reading! We really love our fish!
<Good to hear!>
Re: Very Sick Black Molly... (RMF? Ever seen this type
of prolapsed vent on a Molly?)<<No.>>
I looked into the tank and found my molly dead a few minutes ago
(which I pretty much expected), but I included a picture of her
body nonetheless, just in case you could tell me any more about
the protrusion and maybe help
me prevent my other fish from getting sick.
<Hmm... very odd. Doesn't look at all familiar to me, and
seems a bit long to be a simple prolapsed anus or uterus. I have
seen somewhat similar problems with another livebearer, a
halfbeak, but the swelling was a large,
roughly spherical mass rather than a tube. There are a couple of
photos on an article I wrote for Fish Channel, here:
(RMF, would be happy to send similar if you'd like to add to
this page directly.)
<<Please do. RMF>>
In this case, the swelling was caused by some sort of problem
with the developing embryos, and after dissection the dead
embryos were quite obviously trapped behind the tumour-like mass,
as you can see on the second
Is this contagious?
<Very unlikely; however, female livebearers are sensitive to
stress, and while Mollies are not so commonly stressed as, say,
pregnant Halfbeaks or Stingrays, things like miscarriages are far
from unknown. This underlines
the importance of providing optimal conditions, despite
livebearers being sold as "easy fish".>
Or will keeping my water quality higher in the future prevent
seeing this again?
<Good water quality will of course ensure your fish remain
healthier, across the board.>
Should I still treat the water with anything in case some fish
have it but aren't showing signs yet? Or will I be able to
tell if others have it?
(They're all eating/swimming/acting normally). Thanks loads
for your help and quick response!
<Always happy to offer an opinion.>
Ich Advice, mollies,
more - 06/05/09
I have been reading your site very diligently over the past two days as
we realized two of our black mollies have ich. The information you have
provided and the q/a section has been very helpful. I am sure every
tank, like every fish has a different story and set of issues :-)
<As does every individual>
In our tank we have 4- 2 yr old silver mollies (not even an
1ï¿½), 3 large red Platies, 5 of their off spring and
then ~10 of their off spring (3 generations), also 2 pop belly mollies,
3 black mollies, two (heckle and
jeckle) yellow mollies, 3 baby swordtails, one beautiful
5ï¿½ rainbow shark
and ~15 more tiny babies of a mix (we thing black and yellow). Our tank
has been very ï¿½busyï¿½ as of late.
Anyways our tank heater failed a couple weeks ago and the water temp
spiked to almost 90 degrees (yikes). Now we have ich! Our water
chemistry is perfect! The Ph was a bit high but controlled that by
removing a piece of drift wood.
<Unusual... such material/s generally lower pH with their
From a treatment perspective we have done the following- removed the
carbon from the Whisper and canister filter, used Â½ of the
full dose of Para Guard from Seachem as only two of the black mollies
show spots and we don't want to kill the babies (I would rather
extend the treatment cycle than risk losing them). We have kept the
lights (compact florescent) off except for ~15 minutes to check for
spots daily, closed the curtains to eliminate more light, done ~50%
water changing using a gravel vac and have added the
recommended salt (done once so far). We are slowing raising the temp of
the tank from 74 to 84- should reach 84 by tomorrow night.
I am happy to say that the two fish that visibly had spots are looking
better, the babies and other fish do not look stressed although some
are spending more time near the top ï¿½ not sucking air
- how long do we continue this treatment?
<I'd treat at full dose, per the bottle recommendations>
- How often do we really need to do a water change/vacuum if our
chemistry is good (checking daily)?
<Not at all if so>
- Is there anything else we should be doing?
- Some say that we should stop feeding the fish during this process?
Rumor? I haven't read that on your site.
<I would continue to feed>
- Do we really need to keep the lights off (I miss watching the fish
Thank you very much for your time and input.
<Welcome. Bob Fenner>
Beloved mollies dying en
masse... please help! 6/3/09
About six to eight months ago I bought a 5 gallon rectangular tank and
two pot-bellied mollies (Bonnie & Clyde), a small Penguin BIO-Wheel
filter, and a Marineland submersible heater (as well as other supplies,
such as a hydrometer, net, tropical fish food flakes, etc.).
<Ultimately this tank is too small to be successful with these fish,
the need a larger tank to live out their lives, especially since these
fish are highly interbred and not particularly resilient..>
After this purchase (I now know it should have been before )
I began to research my new fishy companions. I added one more female
(Halo) to ease the effects of the male's 'drive', and
bought Spirulina flakes for feeding. I fed them the Spirulina twice per
day, with the tropical fish flakes every few days as a treat. I am not
proud to say that I cycled the tank with the fish in it, as I already
had fish and only one tank. The tank was kept between 76 - 78F. I
attempted to keep my water slightly brackish, but experienced
difficulties with keeping the water IN my tank... it didn't have a
lid, and after 3 or 4 days, 2 inches of water would have evaporated
away. Because of this loss, I never did water changes so much as water
<This does not accomplish the same thing.>
Much of the salt (Instant Ocean sea salt) ended up on the rim or down
the side. Each time I added water, I also added one to two drops per
gallon of Genesis (which purportedly removes chlorine from tap water),
but did not increase the temperature of the water, which I know now I
should (for the future, what is the best way to do this?).
<A small heater.>
My filter eventually seemed to stop filtering. The BIO-wheel turned
irregularly, and eventually stopped turning at all.
<Best to clean the filter out, often salt will bind up the bio-wheel
and needs to be removed.>
In a very short period of time, the water got pretty gross. NOW I know
the wheel was fine, and it's the carbon filter pad that should be
replaced, but I didn't then. Through all of this learning and
unintentional error, my gorgeous mollies were VERY patient, and perhaps
even semi-healthy. One Saturday morning I returned to my college
apartment from home to see unexpected babies . After several attempts
at counting them, I found that one of the females had given birth to 18
fry, one stillborn. There may have been more initially, but it took me
a few days to obtain a breeding net (
http://www.thatpetplace.com/pet/group/10982/product.web) to round them
up in, and none of them disappeared or were bothered by the adult
mollies during that time. While I was in the FS searching for a
replacement for my 'broken' filter, a breeding net and some fry
food, I decided to upgrade and bought a brand new Eclipse HEX-5
<This is actually a downgrade here and still too small. A tall hex
tank has less surface area, and as a result less gas exchange, and a
lower bioload capacity than a regular rectangular tank.>
I rinsed the gravel and decorations from the old tank with hot tap
water and moved them to the new tank. I filled the HEX with tap water
treated with Genesis, and moved the fry over into their breeding net.
The adult mollies were kept in a large Tupperware container with water
from the tank during the maintenance and renovation, and then moved to
the new tank. About three days after the tank switch, the female molly
that I had originally purchased showed up at the top of the tank, dead
and upside down. All the other fish, adults and babies alike, seemed
<The cleaning of the gravel and decorations probably wiped out a
good portion of your biofilter, causing the tank to recycle.>
It's been about two months since the tank switch and Bonnie's
death, and in the past three days I've lost over 50% of my fish.
First, a few of the fry died. I figured
<Are very sensitive to water quality issues.>
that I might have been overfeeding them, as all of the tank mates
seemed fine (were eating normally, swimming around normally, etc).
<Check your ammonia levels.>
Yesterday the adults didn't seem hungry when I fed them.
<Not a good sign or mollies.>
Today when I came home from work, there were only 5 fry left and Halo
(my treasured favorite) was dead on the bottom of the tank with what
looked like tufts of white (possibly Columnaris?)...
<More likely just postmortem decay.>
Clyde swims in one place and shakes. What caused such rapid devastation
in my tank!?
<Water quality issues here would be the leading candidate.>
I read that high water temperatures accelerate the progression of
Columnaris, so I hesitate to heat up the water.
<I would not think disease is your problem here, instead start doing
some water changes, a gallon a day or so at least until the tank
All I have done so far is put in a new filter pad.
<This actually is probably causing more problems at this point,
removing whatever beneficial bacteria you have cultured. Water changes
will help minimize this problem.>
At this point, I plan on increasing the salinity of the water and
hoping to save those that I have left. I have been working tons of
overtime at work and experiencing various other difficulties and I just
don't feel like I've been giving my little guys enough time.
I'm shocked and a little heartbroken - I don't want to be a bad
fish 'mom'! I'm almost ready to give up on keeping fish
altogether... please help.
<Your short term issue here is most likely your water quality. The
new tank is still cycling and frequent water changes are necessary to
minimize the impact to your fish. Long term you will need a larger tank
to keep these fish healthy for their entire life span. In reality a 5
gallon tank is not appropriate for most fish, its just too small and
Re: Beloved mollies dying en
masse... please help! 6/3/09
The cottony material that formed on the dead fish has formed on my last
Molly, and he is still living.
What would explain this besides post-mortem decay?
<Could be a fungal or bacterial infection, a broad spectrum
antibiotic may help here, along with improved water quality and a small
amount of marine salt.>
The water was cloudy and "fuzzy" looking before I changed
the filter pad, and has now cleared up considerably.
<Most likely a bacterial bloom due to the cycle, not uncommon. The
filter pad gave more space for the bacteria to colonize, leading to a
decline of the waterborne material.>
For clarification, I was under the impression that the
BIO-wheel was where the main culture formed, and that the blue carbon
filter pads need to be replaced once a month
according to the gentleman at TFS). Is this true?
<The bio-wheel does hold a lot of bacteria, but so do all surfaces,
including the gravel and filter pad. When these were cleaned and
removed vast amounts of your biofilter went with it. The filter pad
should be changed often but not at the same time as the gravel is
washed, its too much for the tank to handle. The bio-wheels main
benefit is not necessarily the amount of bacteria it holds, but the
fact that it is highly oxygenated which helps the bacteria rapidly
break down the ammonia and nitrite.>
Molly health question
We have a female bubble molly that has developed a string like
discharge from her rear end that grew to about 5 inches long over a
period of approx 3 days. Mid brown in colour & about 1/16 inch in
diameter. It finally broke away & fish seems unfussed about it. Any
suggestions as to what it is & should we be doing anything about
Geoff & Trudy
<Likely just a dietary thing; Mollies are herbivores and need a
fibre-rich diet. Don't give them carnivorous fish food (standard
tropical flake for example) but instead use things based on algae such
as Spirulina (often sold as Herbivore Flake or similar). Also cooked
spinach, lettuce, peas, etc.
Mollies are generally hardy, but they do have very specific needs with
regard to water quality, water chemistry, and diet that you ignore at
Possibly swim bladder? (Sick
Mollies in a small freshwater aquarium at pH 7... par for the course
I am in need of some serious fish help! I have a 15 gallon tank [just a
few months old, we started with a 10 gallon then with all the babies my
fish had, it was time to upgrade] with 6 balloon belly baby mollies and
<Reina, the problem is that 15 gallons isn't enough space for
either Mollies or Plecs, and as sure as God made little green apples,
some of your problems will come down to this fundamental issue. Mollies
are best kept in tanks around 30 gallons or bigger. This is because
they are extremely sensitive to poor water quality. Plecs need even
bigger tanks; a 55-gallon system is the bare minimum. Plecs are simply
huge fish, around 45 cm/18 inches after two years, and without masses
of space and strong filtration, they cause major problems.>
I noticed right before I bought my Pleco that one of the babies, a
beautiful orange spotted one, has been itching against the side of our
little house. (medium size cottage with a spinning wheel) For fear of
having parasites, I gave the tank parasite clear medicine as well as a
did some water changes and a few days later [with no improvement]
immediately took her out and put her in a 5 gallon medical tank by
herself. [with introducing the Pleco to the tank, I made sure to do a
water change so the Pleco wouldn't be harmed in any way]I monitored
her behaviour there.
<Why did you stick the Plec in a 5-gallon tank? That makes no sense
Always understand, a "hospital tank" should only be used if
the conditions in that tank are at least as good as those in the
display tank. A 5-gallon tank is too small for a Molly, let alone a
Plec, and if the filter wasn't matured properly beforehand, then
conditions are likely to be much worse in this tank than the main
A week or so passed by and I haven't seen her scratching against
Unfortunately I have noticed that she has been swimming funny. I
can't for the life of me figure out why.
<I can. When Mollies get sick, it's almost always because people
keep them in the wrong conditions. They need warm (around 25-28 C)
water with a high level of hardness, 15-25 degrees dH being about
right. The pH level should be 7.5-8, and this is best achieved by
raising the carbonate hardness.
Without exception, Mollies are healthier and easier to keep in water
that is slightly brackish; add marine salt mix (not "tonic
salt" or "aquarium salt") at a dose of about 6-9 grammes
per litre of water.>
the water levels are all safe, maybe the high PH levels that mollies
tend to enjoy is a little lower than standard but not of which I'd
think would be of concern. [the level is reading 7.0] she seem to lay
at the bottom a lot.
<This is far too acidic; raise the carbonate hardness and the pH
should go up to the optimal level. The use of marine salt mix is the
easiest way to raise salinity and carbonate hardness at the same time.
Obviously, you shouldn't keep a Plec in brackish water, so that
catfish will need a new home.>
yet swims up whenever I come near to watch her. I notice that she is
pumping pretty hard to get herself to the surface[when she stops
pumping she seems to sink a little easily]. Her tail is pointing down
and her head is up- sort of as if her body was angled. would this be
some form of swim bladder disease?
<No; this is the "Shimmies" and is very common when people
keep Mollies in the wrong conditions. It's a bacterial infection of
some sort, though the details are vague.>
I am getting increasingly worried. If it is, what should I do for her
to help get her back to normal?
Any advice is appreciated! Thanks, much!
Re: possibly swim bladder? (Sick
Mollies in a small freshwater aquarium at pH 7... par for the course
really) -- 05/02/09
Thanks so much for your help. I guess I should have been a bit more
descriptive, but it was pretty late last night, I guess my mind was
falling asleep on me. The Pleco I have stays at a constant size. It is
Bristlenose Pleco. So I was told he would be fine in my tank.
<Ah, I see. This is why scientific (Latin) names are best! Ancistrus
spp., the common Bristlenose catfishes, are good choices for tanks 15
gallons upwards. On the other hand, they will not tolerate salt, so
sensible choice for the Molly aquarium.>
I put the molly that was scratching herself in the hospital tank. Not
the Bristlenose. The Hospital tank is a tank that actually housed the
baby mollies when they were first born. It's been cleaned, cycled,
and kept up
since babies were introduced to the big tank. I'm sort of confused
because my mother has a 10 gallon tank, and 5 neon tetras and 3
<Neons also need soft water, so they're another bad choice for
life with Mollies. It's really important to review the needs of
each species prior to purchase; at best, advice from "the
guy" at the pet shop tends to be unreliable.>
2 of the mollies were some of the babies that came from my mother molly
who passed away soon after birth. In her tank, they grew to adult
Mine haven't been growing as much, and I even invested in a bigger
With mine smaller, and in a bigger space, I'm confused why with her
crowded ten gallon tank which she doesn't maintain as often as I
do, that the babies grew to adult size. Weird, Right?
<Not really; it's actually quite common for livebearers to [a]
produce lots of babies despite [b] being kept in the wrong
Yet, I have noticed there have been some growth in some of the babies.
Is this slow rate of growth because my levels need to be higher?
<Could easily be the case that your baby Mollies are growing slowly
because water chemistry and/or water quality isn't
Anyways. I'm going to invest in this marine salt, I read somewhere
about using salt to help the tank but I've only known about the
aquarium salt. [I guess it is safe to say that after almost a year,
I'm still new at all of
this.] After raising the levels, is there something that might help
with the shimmies? or would making the tank easier levels to live at
going to improve her condition?
<Tends to get better by itself, when conditions improve. Adding
Maracyn or some other antibiotic can be used if it doesn't.>
Once again, thanks for all the help. Your site has been extremely
helpful, keep up the good work! I'm glad there is somewhere fish
lovers can go besides the sometimes not-so-knowing pet stores.
<Do please keep reading! Plenty to learn, even with supposedly
"easy" fish like Mollies. Good luck, Neale.>
I hope you can help. I have a molly that I believe is sick. I can't
find anything like it on the web. just behind it's gills are red
spots almost like a chunk has been taken out showing the red flesh.
both sides are like this. would you happen to know what this might be.
she's about 2cm long, she is still very active and eating well. she
is silver in colour. I have 2 others that show no signs of this
<It sounds as if your fish is either developing an ulcer, or else
has sustained some physical damage, e.g., from an attack by another
fish. Ulcers occur for a variety of reasons but are typically
related to water quality problems. As you hopefully know, Mollies
require very clean water (0 ammonia, 0 nitrate, less than 20 mg/l
nitrate) but they are also sensitive to soft water conditions,
requiring very hard, basic water to do well (pH 7.5-8.5, hardness 15+
degrees dH). They are best kept in brackish water, which is NOT the
same thing as water with a teaspoon of salt added per gallon! As for
physical damage, that depends on tankmates primarily, but also consider
the ornaments in the tank, swimming space, clumsy netting by the
aquarist or retailer, etc. Without a photo and some aquarium statistics
(size, water chemistry, water quality) I can't really say much more
than this beyond recommending a suitable, tested antibacterial
medication, e.g., Maracyn or Maracyn 2, as opposed to fake cures like
salt or tea-tree oil. Finally, please, if you write back, play nicely
and hit the Shift key once in a while. We do specifically ask for
properly capitalised sentences, not least of all because it makes a
message easier to read. Proper English is the "currency" that
makes this web site work, financially and otherwise. Cheers,
Thank you very much for the advice. I will check all of your
recommendations. My first thought was an injury of some sort. Again I
<Good luck with the fish, and hope it gets better! Cheers,
Hello to the crew at WWM!
I have looked throughout your website at possible causes that could be
contributing to the illness that one of my mollies, Bass, seems to have
contracted. My fiance and I jumped into the aquaria hobby
about 18 months ago and haven't looked back! Since mollies were the
fish we had the best luck with, we kept them. As they grew up and bred
(and bred and bred and bred), we just kept increasing their tank size.
The majority of our mollies now live in a 125 gallon, 6' long tank.
Temp is 80 degrees Fahrenheit; ammonia is 0; nitrite is 0; nitrate is
40 (water change is tomorrow). They get dechlorinator and a bit of
non-iodized salt, but
<Would up the salt, and rather than using cooking salt, switch to
marine salt mix. Besides raising the salinity, marine salt mix
dramatically improves the pH and hardness levels. I'd recommend 6-9
grammes per litre,
the lower end if you have plants in the tank. Check your other fish are
salt-tolerant before raising the salinity. Almost all general problems
with Mollies just don't happen when they're kept in brackish --
freshwater -- conditions. Your nitrate level for example is too high
for Mollies, but the use of brackish water will far reduces the
About six months ago, we purchased a female molly from our LFS and we
decided to name her Bass (we name most of our fish for identification
purposes). Last weekend, around April 11, we noticed that she was
whirling. We immediately prepped our 10 gallon quarantine tank and used
tank water from the 125 gallon tank and placed her into there with some
Formalin and Epsom salts to treat what was suspected to be a swim
bladder issue. We also stopped feeding her for three days, then started
feeding her shelled peas only at one pea every other day because it
takes a while for her to eat a whole one. She started swimming fine on
Thursday, April 16, so we put her back home into the 125 gallon tank.
Bass then started whirling again, so we put her back into quarantine.
Of course, now she is swimming fine, and we are still feeding her peas
and regular fish food on a pattern basis. I joke that I think she is
faking. Other than whirling and swimming as if she is drunk, she acts
<Rocking, listlessness, and "treading water" in Mollies is
commonly put down to something called the Shimmies, a catch-all name
for something caused by a potential variety of things including poor
water quality and certain bacterial infections (particularly
Columnaris). Columnaris, also called Mouth Fungus, is bacterial
infection common among Mollies and often revealed by white-grey patches
on the face and body.>
Are there any suggestions as to what could be the cause of this
Thank you very much!
<Would amend water chemistry as noted, and if you suspect
Columnaris, treat accordingly. Cheers, Neale.>
Re: Molly trouble
Thank you for your quick and thorough reply!
<Happy to help.>
After I received the message in my inbox, I feel I may have needed to
include a few more details than I did previously. The 125 gallon is
home to only mollies of various ages, backgrounds, and types. It is
planted at the moment because the light necessary for some better
plants is expensive. We have already set aside funds for it and will be
purchasing the new light at the end of the month, however. The plants
will definitely help with the nitrate issue.
<OK. Well, since you're keeping Mollies, raising the salinity to
SG 1.003 is a no-brainer. Any plants tolerant of salt will accept this
salinity, provided they're otherwise happy. I have a list of
salt-tolerant plants on my Brackish FAQ, here:
We used to use Instant Ocean (16 teaspoons for the tank in addition to
16 teaspoons of non-iodized salt) in the molly tank when we did water
The problem was that the Instant Ocean stressed them out somewhat.
<Can't think why. If it's safe for seahorses and corals,
better believe it's safe for Mollies!>
Our next step is going to be to find a way to get it set up on a drip
system using an empty water jug, aquarium tubing, and a flow regulator
(this is coming soon) so that we don't have to just dump the
Instant Ocean mixture into the tank all at once.
<Mollies can be acclimated between freshwater and seawater within an
Have done this many, many times. Certainly true for Sailfin and Black
Mollies, might not be the case for the more inbred mutant forms like
Balloon Mollies, but I don't keep them. Wild Mollies at least will
any salinity you throw at them. But, and it's a bit but, your
filter bacteria may need to adjust to dramatic changes in salinity.
From 1.000 to 1.003 shouldn't cause problems, but bigger changes
might. Do always use a hydrometer to check the specific gravity;
don't rely on teaspoons or such!
A basic floating glass hydrometer costs $5.>
When we were using Instant Ocean, however, we lost several mollies
within a few weeks of each other.
<Just don't believe these things are connected, unless the
Instant Ocean was somehow contaminated.>
They were in the category I call the "teens" -- older than
fry, not quite adult.
<Not an issue. Mollies will breed -- readily -- in seawater.>
The symptoms they began to exhibit right after the addition of the
Instant Ocean product were crooked spine and whirling.
<Doesn't sound like a salinity issue; sounds more like a sudden
change in pH, exposure to toxins, or something like that.>
Those fish were immediately euthanized after the crooked spine was
noticed (I will not prolong the suffering of any animal, no matter how
attached I am to him/her/it).
Now we have Bass, who is fine in quarantine but starts moving around
listlessly and whirling once she is placed into general population.
Does this still sound like a myxosporea/nitrate issue?
<Myxosporea is not common in tropical fish because the parasite has
a complex life cycle that requires intermediate hosts. So unless these
Mollies have been kept in a pond, I can't see how Myxosporea enter
into the discussion. As for nitrate, this is an Achilles' heel for
Mollies, but it's difficult to pin down the "toxic level"
accurately. They do seem to be nitrate sensitive compared to other
livebearers, so by analogy to other
nitrate sensitive fish, levels above 20 mg/l probably make them more
prone to sickness. But beyond that, it's hard to say.>
If so, I will gladly find some copper sulfate at our LFS later
<Apropos to what? Copper sulphate isn't much used these days
because it's pretty toxic, though concentrations of 0.15-0.3 mg/l
can be used for up to 4 weeks to treat external parasites and flukes.
Won't do much for fungus, Finrot, etc.>
Thank you very much again!
Shaking Molly has white patches
on her side 03/29/09
I have done a lot of reading but am having trouble figuring out what is
wrong with one of my Mollies.
<When Mollies are sick, the very first thing to do is check the
aquarium: they need warm (25-28 C) water that is hard (15+ dH) and
basic (pH 7.5-8) and preferably brackish (SG 1.002+). Water quality
needs to be excellent; zero ammonia, zero nitrite, and minimal nitrate.
In freshwater aquaria, nitrate is a critical factor, though less so
when kept in brackish or marine conditions.>
Last night she started to shake, but otherwise looked fine. She
wasn't really hiding, but she was staying somewhat isolated from
the other fish, all Mollies.
<"Shimmies". This is neurological and apparently related
to the environment, and not caused by a pathogen, so far is known. So
you should review conditions in the aquarium.>
Today, she has a white patch on each side. It doesn't look like
there are spots or pustules; it looks more like an absence of color.
Today she is hiding. She can swim if she has to, and it seems like she
can swim in whichever direction she chooses, but she spends a good
amount of time resting on the gravel. Her breathing looks ok, although
maybe a little faster--I am not sure.
<Still sounds like the Shimmies.>
Several hours before she got sick, I noticed that two other females
were shaking a bit. I thought they might be having babies, because
another fish just had babies a few days ago. I added some salt (in
water) to the aquarium, and I don't know if that helped, but the
shaking stopped completely within a few hours, and all fish seemed
fine. When the fish that
is currently sick started to shake, I thought she would recover as the
other ones did, but she has not. Now she has these white patches on her
<When you say "added some salt" what are we talking about
here? Some people mistakenly assume aquarium salt (sometimes called
tonic salt) helps. It really doesn't. Such salt is simply cooking
salt, sodium chloride, and while it helps detoxify nitrate, it has no
affect at all on stabilising pH and raising carbonate hardness.>
The water quality is good: no measurable amounts of ammonia, nitrates
or nitrites. It is a brackish system with extremely hard water,
approximately an 8.6 pH, and a temperature of 78-80 degrees F,
depending on the time of day.
<Brackish water is created by using marine salt mix, such as Instant
Ocean or Reef Crystals. In the case of Mollies, I'd recommend
around 6 grammes per litre (roughly 0.8 oz per US gallon).>
Nothing in the environment has changed in the past few days, e.g.,
lighting, feeding schedule, etc. I change about 15% of the water once a
week, the last change being the day before any of the fish started to
What do you think is wrong with her? Is there anything I can do to help
her and to prevent other fish from getting sick?
<It's certainly the Shimmies, and there's really no fix
other than repairing whatever is wrong with the environment. Do see
Thanks so much for your help. I use your site all the time.
Re: Shaking Molly has white
patches on her side 03/29/09
Thank you for your reply.
<Happy to help.>
I am sorry to say that she died yesterday morning, but I still would
like to figure out what could be wrong with the environment for the
sake of all of her friends.
As I said in my previous email, tests are showing no ammonia, no
nitrite, and no nitrate in the water. I have been testing the water
daily just to be sure, and it is consistently good. The aquarium is, in
fact, brackish; SG 1.014 (marine salt, not aquarium salt). The tank is
well oxygenated, the water is extremely hard and slightly alkaline--it
comes out of the tap that
way, so these conditions are stable.
<All sounds ideal.>
Until I first I noticed the problem, the temperature was regularly 80
deg. F, although occasionally it would drop to 79 or sometimes 78 in
the evening on very cold nights. I have since raised the temperature to
82F, and it hasn't dropped below 82 at night. (There is nothing I
can do to control this temperature drop; I have two heaters running,
one of which monitors the temperature and is supposed to adjust itself
accordingly. It simply is cold here.)
<Such temperature changes are well within what Mollies can tolerate,
so can't see this being the problem.>
I am concerned for the other fish, because I have seen a few others
display shimmying behaviors in the past few days, although only
intermittently. For example, they will shake for 10 minutes or so, then
they will be fine for the rest of the day. Everyone is eating well and
swimming normally, and there are many attempts at mating taking place.
It's just that once a day
or so, a few of them will hide and shimmy--only the older ones.
Haven't noticed any shimmying today, thankfully.
<All sounds like Shimmies. There's really nothing much to say in
terms of healthcare; usually it's caused by environmental issues,
though occasionally it's connected with Flexibacter columnaris
infection, in which case an anti-Columnaris antibiotic or antibacterial
could be used. Worth a shot, anyway.>
Update: No More Shimmies!
Thanks, Neale. I wanted to update you on an interesting turn of
When I received your e-mail suggesting use of an
antibiotic/antibacterial, I decided to do a quick water change first.
In doing so, to my surprise, I found that four of my fish had given
birth. The next day, a fifth one.
Perhaps this was, in fact, what was causing all the odd behavior?
<Possibly, though I'm not aware of any connection (which
doesn't mean there isn't one!). Mollies are generally pregnant
12 months of the year, so they're almost always going to give birth
at some point through sickness.
So while there may be a connection -- perhaps a stressful labour? -- it
isn't obvious that there should be one.>
Just in case, I am still treating the entire tank for columnaris. Since
the second day of treatment (also the last birthday), I have not seen
any shimmying. Babies everywhere, but no shimmies.
<Well, the end result is healthy fish, and even better if you have
ten times as many as before!>
Thank you again!
<Happy to help. Enjoy rearing the baby fish; it's a treat!
Mollies: Sudden Death, Health,
We have a 10 gallon tank containing three Glofish and one Cory cat.
<Very close to overstocked for a 10 gallon aquarium>
Ammonia 0ppm with Nitrite <0.3 mg/l and pH 7.0
<Nitrite too high, you want this to be zero., and the pH is too low
We purchased a black molly today and she died almost instantly when
added to the tank.
<Can be a combination of things. Water conditions inappropriate for
Mollies, nitrite levels, and perhaps the Mollie was in poor health to
Is it possible that she was sick, in shock or was it something with our
<There is definitely something wrong with the tank if your nitrite
levels are above 0>
I don't want to try another Black Molly if we have a problem.
<Mollies are not appropriate for this system, Mollies need hard,
almost brackish water to do well.>
If she was sick, is it possible that my tank is now infected and if so,
how do I test?
<Maintain good water quality, keep up with regular changes.>
Mollies with Columnaris and Ich
I'm in a bit of a quandary. I purchased three mollies the day
before yesterday, and placed them in my cycled 10 gallon quarantine
tank (pH: 8.1, ammonia: 0, nitrites: 0, nitrates: 0 -- I had a bunch of
extra cuttings so
the tank is stuffed with live plants).
<Mollies don't do well in small tanks. They're very
sensitive to nitrate as well as ammonia/nitrite, and in small tanks it
is very difficult to keep them healthy for long. Minimum tank size for
small Mollies (Shortfin
mollies, black mollies, balloon mollies) is 20+ gallons, while large
Mollies (Sailfin mollies, liberty mollies) is over 30 gallons.>
Unfortunately yesterday I observed that one of the mollies had what we
used to call cotton mouth or mouth fungus.
<Very common with Mollies, especially when kept in freshwater
I understand, from researching your site, that this is likely
<Indeed. You will need a suitable antibiotic or antibacterial (as
opposed to a make-believe solution such as tea-tree oil or
Today I also observed two Ich spots (sure glad I quarantined). I was
going to go the salt + heat route, but I learned (also from researching
your site), that Columnaris grows faster with higher heat.
<Your options are limited here, but in this case, I'd raise the
salinity to deal with the Ick, and treat with an
antibiotic/antibacterial at the same time. Since Mollies are best kept
at SG 1.003, I'd recommend 6 grammes of marine salt mix per litre
of water. There's not much point trying to keep Mollies in a
freshwater aquarium because they rarely (seemingly, less than 50% of
the time) do well. You're also fighting with one hand behind your
back because the tank is so small, so a difficult job is being made
twice as hard.>
My questions are: Should I raise the heat, and how I can treat both the
Columnaris and Ich concurrently? Also, should I remove my plants?
<Plants will not be affected by antibiotics or antibacterials used
correctly, and a salinity of SG 1.003 is fine for hardy, salt-tolerant
Thanks very much for your help and your wonderful website.
Re: Mollies with Columnaris and
Thanks very much for your help. The Mollies are currently in a ten
gallon tank because they are in quarantine (their permanent home will
be a 40-gallon heavily-planted breeder tank).
<Ah, that makes sense. A 40-gallon system will be perfect.>
The water parameters of that tank are:
Carbonate hardness: approximately 200 mg/L CaCO3
<That's 200/17.8 = 11.2 degrees KH. That's extremely high,
and while perfect for Mbuna or Central American livebearers, a lot of
other fish will find that a bit on the hard side for their tastes. Do
be aware when choosing fish and plants.>
Their tankmates will be Wrestling Halfbeaks, Scarlet Badis, White
Clouds, and Threadfin Rainbows.
<Halfbeaks will thrive, the others should tolerate, but may not show
optimal colours or longevity.>
I was hoping the Mollies would do well without salt because of the high
pH and hardness, and I wasn't sure (aside from the Halfbeaks)
whether the plants and other residents would appreciate the salt.
<Plants that tolerate hard water generally do well in slightly
brackish water too; species such as Vallisneria, Hygrophila, Java
ferns, hardy Crypts, etc. If you have plants that need soft water,
chances are they
aren't going to thrive a this level of carbonate hardness either,
so it's a moot point. As for the fish: Halfbeaks tolerate salt
well, but the others are truly freshwater fish.>
But I will add salt and remove some of the other residents and non-salt
tolerant plants if necessary.
<Would be my recommendation. Mollies deserve a tank of their own:
they're spectacular fish, and wonderful pets. But they are finicky
in freshwater systems. They need perfect water quality. You might
decide to medicate them in the quarantine tank, and when they're
healthy again, try them out in a plain freshwater tank. With luck,
you'll be okay. But if you find you're constantly having to
deal with Fungus and Finrot, remove the Minnows, Rainbows and Badis,
add a little salt, and maintain the system at SG 1.002-1.003.>
I've started to slowly raise the salinity of the quarantine tank,
and I'm off to the LFS to pick up the antibiotic and a hydrometer.
I believe we have Maracyn and Maracyn II available here (Canada), so I
A couple more questions, if you'll bear with me:
Which Maracyn product would be most effective against Columnaris?
<Maracyn rather than Maracyn 2 is usually used first. It contains
Erythromycin, which should work on Flexibacter columnaris.>
If the Mollies recover, when would it be safe to place them into my
main tank (so that Columnaris does not contaminate that tank).
<Columnaris, like Finrot, is a disease latent in all tanks, and the
bacteria involved is presumably harmless most of the time. It appears
not because a fish "caught" the disease, but because the fish
weakened, and its immune system overwhelmed. So provided the other fish
are healthy, you shouldn't worry about cross-contamination.>
Re: Mollies with Columnaris and
Ich - Update 04/03/09
Thanks very much, Neale, for your advice. Just thought I would give you
an update on the Mollies. I used the salt + heat treatment for the Ick,
and the Ick has disappeared.
For the mouth rot, I couldn't find Maracyn at my LFS, so I used TC
capsules (tetracycline). The mouth rot hung around during the course of
the treatment (5 days), and then I had an ammonia spike (the packaging
on the TC capsules claims that they will not affect the biological
filter, but I suspect otherwise).
Unfortunately one of the Mollies died (oddly, it was the healthiest,
<Sorry to hear that; I wonder why?>
I subsequently performed 75% water changes for the next several days to
control the ammonia, used activated carbon to remove the tetracycline,
then added some nice filthy filter media from my other tank to
repopulate the nitrifying bacteria. Over the next several days, the
mouth rot on the remaining Mollies disappeared, but I'm not sure if
I can attribute it to the tetracycline or the water changes.
<It's a combination: the antibiotic kills off the bacteria, but
improved water quality allows the fish's immune system to repair
the damage and prevent re-infection>
Anyway, the remaining Mollies have recovered, and in a week or so, I
will remove them from quarantine and place them in my 40-gallon
Also, you were right, the salt did not seem to affect my plants
(Hygrophila polysperma, Hygrophila corymbosa, Rotala rotundifolia, Java
Moss, and Bacopa monnieri).
<Not sure about Rotala, but certainly the others are happy in
brackish water, let alone slightly salty/warm water of the sort used to
Thanks again for your help,
<Thanks for the update, Neale.>
Sad State of a Dalmatian
FW System/Stocking/Toxic Water Conditions 3/18/2009
Dear WWM Crew-
<Hello Kim, Mike V here.>
I have tiresomely researched what could be wrong with my Molly- but to
no avail. Please help! This is quite a detailed history, but hopefully
my including it will allow your expertise to see what I cannot. The
situation is as follows:
<Will certainly try to help.>
I wanted to expose my son to the wonderful world of fish and begin
teaching him how to properly care for an aquarium. I have had an
aquarium in the past and understand it is not a "passive"
pet. I also understood that I would be doing all of the work (he's
only 2) so I refreshed myself with books from the library, researched
on line and asked advice of friends.
<Kudos to you for researching!>
In January, 2009 I decided upon a 10 gallon tank and chose 5 Platys and
2 Dalmatian Mollies.
<A bit overstocked for a 10 gallon tank. Mollies are not easily kept
in these conditions.>
I was using a Bio-Wheel 100 filter. I am religious with 20%-25% water
changes every Saturday, and am careful to maintain a water temperature
of 76-78 degrees. I add aquarium salt once per month for the
Mollies and use stress-zyme and water conditioner with every change. My
fish were doing well and I had 2 batches of fry- some were Platys and
some Mollies. I installed a floating breeder trap for the babies, and
purchased baby brine shrimp for the fry, feeding them ½
frozen cube per day. I feed the elder-fish flake food, then substitute
a treat of frozen blood worms or Daphnia once a week.
<Sounds good so far.>
Last month my filter died. Stopped completely- I do not know why. I
purchased another filter immediately and installed it the next morning.
I was encouraged to buy an Aqueon. The Bio-Wheel 100s were
out of stock, and I was told this was a better filter anyway.
Approximately 3 days after the filter change, all but 3 of the babies
have died, along with one of the Dalmatian Mollies. I tested the water
and came back with a horror- Ammonia at nearly 5 ppm, Nitrite and
Nitrate off the chart and a Ph of 7.5.
<Mollies are much more sensitive to water quality than the
Obviously, the water conditions were atrocious. I did an immediate 50%
water change, followed by a 25% water change every 3 days for a week,
hoping to clear out the mess.
<The biological filtration was removed when the old filter stopped
running, forcing the tank to cycle over again..>
Current conditions are Ammonia at 0.25, nitrate/trite at 5 and Ph at
7.8. I think the water changes have really stressed my molly- she
hovers by the heater, head up, near the top of the tank (not
<Not the water changes, the toxic water conditions.>
My Platys and 3 remaining babies are doing well. However, I cannot get
the Ammonia or Nitrate/Nitrite to 0. I do not know what is happening.
Is it possible the helpful bacteria Bio-Wheel in the
older filter disappeared when I switched filters?
<This is exactly what happened. The biological filtration will come
back with time.>
The day after the male Dalmatian molly died, the remaining female
Dalmatian Molly swam around
incessantly. I would say frantically. Now she hovers close to the
heater (temp is 78) and faces head up toward the top of the water. She
is swimming (not floating), and comes out for food.
I will continue with water changes until 0 is reached for ammonia and
nitrate/nitrite, but is the frequency of
water changes also destroying any good bacteria growth or causing her
additional stress? Please advise- I am hoping to save my Molly.
<Monitor water quality closely and stop feeding. by feeding, you are
adding more ammonia to the tank. Add a product called PRIME - It will
detoxify the ammonia, nitrite and nitrate.>
Re: System/Stocking/Toxic Water
Conditions Follow Up 3/19/2009
Re: Sad State of a Dalmatian Molly
Thank you so much for you quick and helpful reply!
<You're very welcome>
Although I was unable to find PRIME at my local store I did purchase
and use AmQuel Plus.
<That will work as well.>
I am VERY happy to say that my tank is already testing better.
I did an additional 20% water change today, added the AmQuel Plus and
several hours later re-tested the water. Although Ammonia is still
registering at 0.25, the Nitrite is at 0.5 ,Nitrate at O and Ph at 7.4.
The water changes may have helped this before the AmQuel (unless it
gets such quick results)- but I am still thrilled.
<A combination of both really, the AmQuel detoxified the ammonia and
nitrite - which is why you are still detecting it.>
My fish are breathing a sigh of relief as well - especially the
She is swimming around, no longer hovering and seems quite alert. I
have 3 additional questions:
1. You suggested I stop feeding for the time being. For how long? Until
ammonia is at 0, perhaps?
<Stop feeding (or feed very little every two days) until the ammonia
and nitrites drop to zero.>
2. Do you suggest I add the Amquel Plus with each water change until
ammonia is at 0? (The directions on the AmQuel are unclear!)
3. What could I have done to avoid this? When a filter fails like that
is there a proper way to protect your fish - I don't ever want to
put them (or me) through this again.
<The biological filter was on the bio-wheel. When that was removed,
the tank crashed. In my opinion, this is the one significant weakness
of a bio-wheel system - they work a little too well. Do make sure that
biological filter does not get disturbed. You can rinse them off in
dechlorinated water, but that is all. If it were me, I would add a few
small pieces of dead reef rock (A couple pieces of rubble) - it will
your system slightly, and is porous enough that a bacterial colony can
be established inside the tank as well as on the filter.>
Again, thank you. I am hopeful my tank will finish its new cycle soon
and all will be well in the aquarium again. For now- my Molly and
friends thank you.
<Again, my pleasure, do let me know how it all turns out.>
Itching, shimmying, clamped
fins? Reading, FW 2/24/09 Hello, I have been
reading up and I think some of my mollies either have ich or parasites.
Some of them are glancing against objects such as gravel, plants, my
log ornament etc... I have seen that many medications require to
"remove carbon from filter." What does that to anything and
how would I go about doing that? <Is to prevent the carbon from
chemically filtering, removing the medication> If this helps I have
a 12 gallon eclipse system that has a bio-wheel. I have 3 full grown
mollies and one younger, smaller one, and two guppies. I have already
removed one fish with serious "itch", shimming, and clamped
fins (The symptoms in my main tank.) My nitrate and everything is fine
but my nitrite increased to a scary level. I have been doing daily 30
percent water changes for around a week but nothing has helped. Plus
what medication/advice would you say to use to help my tank? Thanks for
everything, Hannah <... In order to help you we need to know what
your water quality is, the history of this set-up... Please read here:
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm and the linked
files above... and write back with information as others have. Bob
Black molly with shiny scales
near gills 2/21/09 My son has a black molly in a
ten gallon tank that appears that its gills are turning shiny (or
falling off...can't tell). It was in serious distress a few days
ago (not eating, staying at the bottom of the tank with little
movement), but seems better as I discovered the pH was very low. I am
currently adding salt (as Mollies need) and baking soda staggered
between water changes to get the levels as needed. The molly is
responding, but the shiny area remains near the gills and on the head a
bit. Might this be velvet or Ich? What is the difference in a Molly? I
am also noticing a few (3) small spots on its body. This molly is in a
10 gallon tank with 4 tetras, 1 goldfish, 1 Gourami, 1 Otocinclus, and
1 very young platy. Your help is appreciated...Wanda <Wanda, Mollies
aren't really good community fish and certainly can't be kept
in a 10 gallon tank. They're too sensitive to water quality issues
and pH variation. The fact the pH has dropped in your tank clearly
shows that it is dramatically overstocked. There's no real solution
to this problem until you up the size of the aquarium to at least 20
gallons for Mollies and in all honesty 30+ gallons for Goldfish. Me
telling you anything else would be lying. In the short term, adding
marine salt mix (not tonic salt or baking soda!) at a dose of 6 grammes
per litre will dramatically improve your success with Black Mollies.
While Platies will tolerate such conditions well enough, Tetras,
Gouramis, Goldfish and Otocinclus will not. So it's an either have
those fish OR have healthy Mollies, but there's nothing really in
between. It's most likely your Molly has either Finrot or Fungus,
both being exceedingly common when Mollies are kept inappropriately.
The face region gets silvery as excess mucous is produced by the skin.
Treated properly (e.g., with anti-Finrot medication other than
Melafix/Pimafix) it clears up quite well. But it will come right back
if the fish is kept in the wrong conditions.
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm Finally, please
let me stress than small children don't "have" pet fish,
or really any other kind of animal. The responsibility lies with their
parents, and it's up to you to decide whether to own pet animals
and if so, to make sure those animals are correctly maintained. In this
instance, there's a too-small tank filled with fish that are
fundamentally incompatible with one another. Little kids don't know
better, but their parents should be able to navigate a book store or
library prior to purchase. The fact Mollies are difficult fish is far
from a secret, as is the fact that tetras and Otocinclus are social
animals that need to be kept in groups of 6+ specimens. I've
written a few words on stocking 10-gallon tanks at the link below, and
would suggest you peruse this for some ideas. If upgrading your tank
isn't an option, any decent retailer will take back unwanted fish,
usually for credit.
Poecilia/Mollienesia (health, water
quality) 2/10/09 Hi, my name is mike. <Hello
Mike,> I have a white balloon Molly that is sick. My water
parameters are: pH is 7.2, Ammonia is 0 ppm, Nitrate is 5.0 ppm,
Nitrite is 0.25 ppm. The tank is a 20 gal. freshwater with no salt at
all. <Well, there's the first problem. The tank is too small and
has the wrong water for Mollies. Mollies need big tanks because they
are sensitive to poor water quality. You have poor water; ergo, your
Mollies will get sick. In fact the nitrite level is way too high for
any aquarium, and you need to URGENTLY review feeding, stocking, and
filtration. Your tank will never work correctly with 0.25 mg/l nitrite:
fish will constantly be getting sick. As you mention salt, you probably
realise Mollies appreciate salty water. It isn't essential in a
well-run, big, clean tank with hard, alkaline water -- but your
aquarium is none of those things. The addition of marine salt mix (not
tonic/aquarium salt!) will raise the pH, hardness, and salinity to
levels that favour Mollies, and indeed many other livebearers as
well.> The tank is shared with two Goldfish, One Dwarf Gourami, One
Angel fish, two Platy's and two Cory's. <Platies are good
companions for Mollies, Goldfish potentially so, but the others
shouldn't be here because they don't really like brackish
water. Up to around 3 g/l, both Platies and Goldfish will do fine.>
None of the fish nip at each other and all look well after almost three
months together (after cycling for a month) The Molly, just one day
ago, has been laying on the bottom of the tank breathing very shallow,
not eating and not passing waste, listing and swimming nose down on
occasion and backwards sometimes, but every once and awhile will swim
just fine and go to the surface (but very rare) the fish looks like
it's paralyzed to a degree. <Shimmies or equivalent...
dying...> The Molly has Been in a separate tank for about 20 hours
now, filled with some water from the original tank and some new water,
both tanks have identical water and the filters are the same with an
air stone working off the same air pump as in the larger tank. I've
looked through most of the site about Mollies and some about Angel
fish, and found similar but not the same symptoms. I feel horrible for
the poor thing and was wondering if there is anything at all I could do
to help it. Thank you in advance for the help trying to make the fish
better. <Angels and Mollies are not compatible. Review the needs of
Mollies, set up a tank as required, and enjoy better success.
Re: Poecilia/Mollienesia (health, water
quality) 2/11/09 Thank you so much for your reply
and the advice you gave, but unfortunately the molly didn't make
it. I feel horrible that my incompetence killed an amazing little fish
like that. <Not incompetence, merely lack of knowledge. Do read a
fish encyclopaedia before spending any money: it's pretty widely
known Mollies like a little marine salt mix in their water, and while
not essential, it does make them much easier to keep. Because of this
requirement, I recommend keeping them with species that tolerate or
enjoy a little salt too, such as Platies, Swordtails, or Guppies.
Indeed, most any livebearer will do well. Australian Rainbowfish and
many Killifish also fall into the salt-tolerant category, so it's
really not that big of a deal. A box of Instant Ocean marine salt mix
will last months at the required dosage, so it's a lot cheaper than
[a] buying new fish and [b] buying fish medications.> I bought a
larger tank yesterday afternoon (along with a canister filter and new
sandy substrate) and look forward to creating a much better environment
for the fish that have me and my family glued to the tank for hours at
a time (well maybe just me most of the time) <Ah, a tank with a
sandy substrate opens up LOTS of options, such as Gobies. Look up
Knight Gobies (Stigmatogobius sadanundio) and Violet Gobies (Gobioides
broussonnetii) as examples.
need brackish water, and positively THRIVE alongside Mollies at, say,
SG 1.005 (about 9 grammes salt mix per litre). Violet Gobies are big,
ugly but really funky animals that make great pets. Faces only a mother
could love! Watching them filter feeding on live brine shrimp is one of
the most fun things in the hobby. They're gentle giants, and
won't even eat livebearer fry if properly fed on worms, crustaceans
and the odd algae wafer.> I do thank you for the advice and all the
priceless information you guys diligently dole out about such a great
hobby and hope that one day I will be able to help someone with as
well. <We're happy to help.> Thanks so much Mike <Cheers,
Molly disease? 1/19/09 Hello, <Hi>
I bought a female Sailfin molly from a pet store 2 days ago. It was in
a brackish/ marine tank (1.019ppm), and when I got home, I realized it
had around 6 white spots on its tail that didn't look quite like
ich, or fungus. Ich treatments didn't work, so she is on Pimafix
now. What should I do? Thanks <What water conditions is it in now?
If it came home with "Marine Ich", Cryptocaryon irritans, and
it is now being kept near FW levels then that alone will solve the
problem. Also there is no treatment that would cause you to see a
change in just two days, all need the parasite to cycle to a different
stage of it's lifecycle to be effective. I would discontinue the
Pimafix, as it is worthless at best, and monitor for now. Also in
future correspondence please spell and grammar check your queries
before submitting, otherwise we need to do this for you before
Sick Dalmatian molly, 1/19/09 Hi I have
a 20 gallon tank. <Ok> I started it about three weeks ago with a
male Dalmatian molly. And about four days later I added 2 female
Dalmatian mollies, then I got three peppered Cory cats about a week
after that. <I am guessing this is a freshwater tank, in which
mollies are very difficult to keep. You would probably be better served
switching them out with one of the other livebearers, such as
swordtails or Platies which are much more forgiving.> Then I was
having my water tested about 2-3 times weekly and everything has been
fine so today we decided to get some more fish to finish our tank. We
got 3 golden mollies, 4 guppies (2 female, 2 male), 7 neon tetras.
<This is too much and incompatible life. Mollies and guppies do much
better in brackish water, or at least very hard freshwater, while the
tetras are at the other end of the spectrum needing soft, acidic water.
Also neon tetras can be very difficult to keep as well, definitely not
what I would consider "beginner" fish.> I asked the guy at
the Petco if that would be to many fish for my tank and he told me no
as long as I do a water change every three weeks. <I disagree, I
think you do have too much, and fish that just don't share the same
environmental needs.> But I got home and let my fish get use to the
water for 20 minutes before adding then I put them all in. And now my
male Dalmatian molly will sit at the bottom of the tank and he kind of
jerks from side to side I'm not sure if he's just stressed out
from me adding all of the fish at once or if something else is wrong
with him. <Could be water quality related, adding this much life
quickly can cause ammonia spikes as the bio-filter bacteria catches up
to the new waste levels. The mollies would be the first fish to show
signs of this.> I really don't want to lose him is there
anything I can do for him? Thanks, Cherie <For now lots of water
changes and minimal feeding until parameters stabilize, but I think you
will need to address your stocking choices to help you achieve long
term success. Please see here for more on Mollies
http://www.wetwebmedia.com/FWSubWebInd ex/mollies.htm .>
Molly Behavior/disease 1/4/09
Hello, I have a 55 gallon freshwater community tank. I have some
tetras, livebearers, and small catfish. I specifically have 4 small
black mollies (still babies), 4 silver mollies, and 1 starburst molly.
My water is perfectly fine. My male silver molly has been acting
strange. He hides in every corner he can find, and when not hiding, he
is swimming behind plants, head up. He never eats the food, and just
hides. He acts sick, but there is nothing on his skin. 3 of my 4 black
mollies are in a quarantine tank for lip fungus. Help! <Hello
Rachel. One problem with Mollies is that they are not reliable
freshwater fish. Most aquarists experience what you do when they are
kept in freshwater tanks: lethargy, loss of colour, odd swimming
behaviour, and random diseases including Finrot and fungus. The only
100% reliable way to maintain Mollies is to treat them as brackish
water fish. Buy some marine salt mix -- not "aquarium salt"
or "tonic salt" -- and add the marine salt mix to each bucket
of water at a dose of around 5-6 grammes per litre. Marine salt mix
contains carbonate salts that raise the hardness and sodium chloride
that raises salinity. Together these things stabilise the pH and reduce
the toxicity of nitrate, and it appears to be these things that help.
(Tonic/aquarium salt only contains sodium chloride, and so doesn't
do both these things, and is consequently a waste of money.) Mollies
thrive in brackish water, and at low salinities so will other
livebearers including Guppies, Platies and Swordtails. But do
understand that most catfish and tetras do not appreciate brackish
conditions, and consequently shouldn't be kept with Mollies.
It's a very common mistake for people to buy Mollies for community
tanks -- despite the fact most aquarium books state clearly Mollies
prefer slightly saline conditions. Do read here for more:
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm Cheers, Neale.>
Thanks! <Most welcome. Neale.>
Molly Disease Question Hello Neale,
Earlier I asked about my molly acting strange, and not swimming, and he
died. I have 9+ mollies and all are completely healthy, so I really
don't want to change my tank to brackish. I was worried if that was
some kind of disease, and will it spread to my other mollies? <It
isn't a disease so much as an environmental issue. In freshwater
aquaria, Mollies simply aren't durable. Put it this way, something
like 50% of the Mollies stuck in freshwater tanks die within a few
months. Sometimes it's from an obvious disease like Fungus or
Finrot, and sometimes from something probably related to poisoning of
some type, resulting in lethargy and odd swimming behaviours, what
aquarists call "the Shimmies" after the dance. Either way,
the Mollies die. But when Mollies are kept in brackish or saltwater
tanks (yes, saltwater tanks) they are astonishingly hardy, and can be
used even to cycle filters! Your Mollies may well be fine in your
freshwater aquarium, but three, six, twelve months down the line things
could be (and likely will be) very different. It is absolutely true
that Mollies are usually freshwater fish in the wild, so they don't
"need" salty water in the wild. But under aquarium
conditions, for whatever reason, adding a small amount of marine salt
mix seems to make all the difference. I recommend around 5-6 grammes of
marine salt mix (Instant Ocean, Reef Crystals or whatever) per litre of
water. This won't cost much, and at this dose, you can keep Mollies
perfectly well with other livebearers.> I don't want my very
nice mollies to die. I did a complete water change yesterday, and all
are fine so far. <OK.> I would like to know what was that
disease? <It's honestly a mystery. At the moment, either
nitrate/nitrite toxicity (which sodium chloride reduces) or pH
variation (which carbonate hardness prevents) are the suspected issues.
Either way, marine salt mix counters the two problems, and thereby
provides a useful tool. If your tank has a high level of carbonate
hardness (7+ degrees KH) and zero nitrite and nitrate, you might be
able to keep your Mollies just fine without marine salt mix. But the
reality is that for casual fishkeepers who don't have the time to
fuss over water chemistry and quality, and just want to keep their fish
the easy way, in local tap water, changing 25% each week, adding marine
salt mix is the solution.> Thanks! <Cheers, Neale.> re: Molly
Disease Question Ok! Thanks for all your help! <No problems. Cheers,
White Feces ~ 01/01/09 Hello, <Hello
again!> About a year ago I emailed you about my sick mollies,
since then I moved them into a brackish tank, and they have been
perfect! <That's the idea!> I even added two more
females and was surprised to find baby mollies a few days later.
The babies are all grown now and everything has been great, until
today. I noticed today that my adult balloon molly, Flo, had
white stringy fecal matter hanging from her bum, that has not
dropped, its been there for more than an hour. <There are
really three things that can be relevant here. If there are red
worms appearing from the anus (usually obvious because they move)
then the Molly is infected with Camallanus and will need to be
treated with an anti-worm medication.
http://www.wetwebmedia.com/FWSubWebIndex/nematodesfwf.htm If the
faeces contain much mucous, so that they appear pale, often semi
transparent, then your fish might have a Hexamita infection, and
will be needed to be treated with an anti-Hexamita
(Hole-in-the-Head) medication. Hexamita is commonly associated
with lethargy and general lack of condition (pale colours, weak
swimming, etc.). http://www.wetwebmedia.com/metranidazole.htm
Finally, there's plain vanilla constipation: very common
where herbivorous fish such as Mollies are concerned. In this
case the faeces will be coloured, often brownish or off-white,
but solid rather than semi transparent, and dry looking rather
than mucous covered. Mollies need to eat mostly green foods, and
in the aquarium things like thinly sliced cucumber and sushi Nori
sheet work great alongside a balanced algae flake or algae wafer
staple food. Daphnia and brine shrimp are good aids to
constipation, as is adding small amounts of Epsom salt. Although
the article linked here is written for Mollies, it applies 100%
http://www.wetwebmedia.com/FWsubwebindex/gldfshmalnut.htm > I
have never seen this before, and after reading a bit online, I am
very concerned that she has parasites. <By all means try a
systemic anti parasite infection that treats worms and
Protozoans, as they're the two likely causes of troubles in
the digestive tract.> I am very attached to Flo, she is my
first fish. What should I do? Should I wait to do anything? How
do I treat her, and not kill the babies? <Medications safe for
Flo should be fine with her babies.> The mollies are in a 16
gallon brackish system, currently there are 14 mollies in the
tank, 5 of which are babies. I just did a 25% water change today,
and all levels are normal. Please Help! Thanks, Lauren <Hope
this helps, Neale.>
Sick Balloon Molly
Hi there, I wrote to you a little while ago and I think you probably
saved my fishes, I'm just hoping you're able to do the same
I have a 90L tank with 2 female mollies, 5 guppies, and about 20 Molly
About 2 weeks back I noticed that my Dalmatian balloon molly was acting
a little subdued, hiding and not swimming about much. I checked the
levels and the nitrites were high, I sorted those out and she seemed to
go back to normal. I've recently noticed all of the fish (including
the fry) scraping themselves on everything solid in the tank, but none
had any outward signs of parasites. I went out and bought Sterazin Gill
and Body Flukes treatment, and have been using the recommended dose.
After 2 doses, I have come home to find my Dalmatian molly, pointing
downwards, trapped between a plant and the wall. I thought she was dead
but noticed she was still breathing. After bringing a net close to her,
she swum off but has looked very ill since. Her stability seems
severely affected, she's floating all over the place, just moving
with the flow of the water, seemingly unable to control her movements,
and bashing into things. She's often completely vertical, either
pointing either up or down. Occasionally she'll come to rest in a
plant upside down, and stay there motionless until I get scared and
make her move. What's wrong with her? Do you think that I can save
her? And should I stop the fluke treatment? Thanks for you help
<Sterazin is a medication that has been around for years. It is
generally well regarded, and I'd be surprised if it was causing ill
health, assuming it was used correctly. Do check you dosed the tank
correctly: all medications are poisons, and the "art" is
using them in the right amounts.
When measuring out the dose, it's important not to overdose.
It's also a good idea to increase aeration when treating, because
sometimes these medications cause the amount of oxygen in the water to
drop. Also you have to remember to remove carbon from the filter; if
you don't, the medication gets sucked up by the filter without
doing its job. In any case, the thing with Mollies is that it is
extremely difficult to separate actual diseases from the fact they
almost never do well in plain freshwater conditions. I'd insist
they be kept in brackish water conditions, at least SG 1.003 (about 6
grammes marine salt mix per litre). It's remarkable how many sick
Mollies pep up when kept in brackish water conditions. The
"treading water" behaviour often seen with Mollies is called
the Shimmies, and is particularly common in tanks where Mollies are
kept in freshwater. And no, adding a teaspoon of tonic salt per gallon
doesn't make an aquarium brackish! Besides salinity, nitrate is
highly toxic to Mollies, as are rapid pH changes, so these are two
factors to review. Since Mollies and Guppies both do extremely well in
brackish water, adding marine salt mix is the cheap and easy way to
keep them in good health. Cheers, Neale.>
Re: black mollies
hi its me again so I went looking for marine salt and cant find it can
I use the aquarium salt and I have also bought Ick remover I put some
in do I do my water change every day for two weeks or every other
<Marine salt mix is better. MUCH better. If you're serious about
keeping Mollies, make an effort to get (perhaps mail order) marine salt
Ordinary aquarium salt is not nearly as good. It doesn't raise the
pH and it doesn't increase carbonate hardness, both critical to
ensuring Mollies stay healthy. Some people make the mistake of thinking
aquarium salt is a cheap alternative to marine salt mix: it is not!
Marine salt mix is better.
If you live in North America or Europe, buying marine salt mix should
not be difficult. As for water changes, ordinarily you should be doing
them weekly, or at least every two weeks if the tank isn't heavily
stocked. But when using medications, usually the instructions of the
medication will tell you when to do water changes. Commonly you do NO
water changes until AFTER the last dose. Finally, please use proper
grammar next time (e.g., capital letters). We often just bounce back
messages that ignore this rule.
You've been warned! Good luck, Neale.>
Re: black mollies, sys.
Hi, is Marineland Instant Ocean Marine/Reef Sea Salt the kind of salt
that I need? I'm going to order in online but I want to make sure
<Yes indeed! Absolutely perfect. Instant Ocean, Reef Crystals,
Crystal Sea, Kent Sea Salt, Petco Premium Sea Salt... buy whichever is
cheapest in your neighbourhood. All are perfect for brackish water fish
and superb for use
with livebearers such as Mollies and Guppies. Use 6 grammes per litre
of water (about 0.8 oz per US gallon). This isn't very much:
between 15-20% the amount needed to make normal seawater, so a box that
makes 25 gallons
will actually make around 150 gallons of water suitable for your
Re: Help! Mollies/BB Gobies 11/17/2008 Hello,
again, <Hi there, BobF this time> I had written in a couple of
months ago with a concern about my Dalmatian mollies after the BB
gobies I had purchased all died (see below). <Noted> Since then,
everything had been fine with the mollies, until the other night. My
adult molly, Lucky, seems to be ill - but I'm not sure if she is
really sick, or just getting old. I got Lucky 10 months ago, but
I'm guessing she's much older since the babies she had when I
first got her are still only half her size. Anyway, I noticed Lucky
lying at the bottom of the tank two nights ago, very lethargic. I sat
there watching her for a while, wondering what was wrong. She
didn't come up to eat with the others, so I continued to watch.
After a few minutes she moved to the other side of the tank, hid behind
a plant, then began what looked like a seizure, for lack of a better
word. She started shaking her head back and forth, then rolled a couple
times, then went nose down and just lay there. <Yikes!> I thought
that was the end, but she was still breathing, and by the next morning
she seemed fine. She came up to eat, nibbled on some seaweed, then went
on about her business. Again in the evening, she was lying at the
bottom, lethargic again, then the same seizure-like activity happened
and she sank to the bottom and rested on her side. Same thing today -
eating fine in the morning, seemingly normal, then by the evening
lethargic, not eating, seizure. She looks fine, physically - she
doesn't appear pregnant, did not just have babies, it's just
her behavior that is very concerning. Any ideas? <Alarming
behavior... perhaps something internal... not treatable> About the
tank - I have a 30 gallon brackish (1.004-1.005) tank. Nitrites,
nitrates, and Ammonia are all zero, pH is 7.6. In the tank I have
Lucky, along with 2 "teenage" mollies, and 5 baby mollies -
about 4 months old. There are a couple Anubias plants, but mostly
artificial plants. Any thoughts would be greatly appreciated. Everyone
else in the tank seems happy and healthy - knock wood. Thanks for you
help, Amy <Given your report of the system, conditions, apparent
sophistication... health of other livestock, I do think this is
"something" anomalous with the one fish... perhaps
attributable/label-able as "old age"... Bob Fenner>
Black mollies... Hlth., sys. 11/14/08
hi I have two black mollies and one has white discoloration on him and
I understand it could be a fungus and I should do a 50% water change
and use Maroxy to help and add a tea spoon of salt to my tank but
I'm worried for my other fish I also have guppies and other mollies
and platys will the Maroxy or the salt harm them? <Greetings.
Guppies, Mollies and Platies will all do well in brackish water.
Maintain this aquarium at SG 1.003 (6 grammes, about one teaspoon, or
MARINE salt mix per litre of water). Understand this: aquarium or
cooking salt won't help. You need to be using marine salt mix,
i.e., products like Instant Ocean or Reef Crystals. These not only add
salt, but also raise the pH and hardness levels. Black Mollies, and
indeed all Mollies, do best in brackish water and almost always get
sick in precisely the way you describe when kept in freshwater tanks.
Dalmatian Molly 11/11/08 I have a Dalmatian Molly
and I think it may be pregnant. Another person said it could have
bloat, I have never heard that term before. I have tried looking at
pictures on line, but my molly is twice the size. Any help would be
appreciated. Thanks, Lynn <Lynn, "bloat" is another word
for dropsy (technically, oedema). It follows on from organ failure, and
is almost always associated with chronically poor environmental
conditions. The give-away clue to oedema is that when viewed from
above, the scales bristle outwards from the body, so that the fish
looks like a pine cone. In the case of Mollies, the most common problem
is trying to keep them in freshwater. Mollies rarely do well in
freshwater, and unless you're a super-expert fishkeeper willing to
carefully monitor pH and nitrate concentration, just isn't worth
trying. When Mollies are kept in brackish water they are
infinitely hardier and more easily maintained (aim for around SG 1.003,
upwards of 6 g (one teaspoon) of marine salt mix per liter). Next up is
diet. Mollies are herbivores, and a very common mistake people make is
to give them standard tropical fish food. Mollies should receive such
foods only occasionally, a couple of times per week maybe. Otherwise
their diet should be algae, algae, and more algae. There are
algae-based flakes and pellets on the market, and these are ideal. If
given the wrong food, Mollies are prone to constipation, and this
causes symptoms similar to oedema. Finally, there's pregnancy. When
pregnant Mollies do indeed swell up, but around the abdomen only. The
fish should only look "swollen" for a couple of weeks, at
which point the fish gives birth and quickly deflates down to her
normal size. Gestation is actually about 4-6 weeks, but only the
last couple of weeks cause really substantial swelling. Once you've
bred Mollies a few times, it's easy to recognize the cycle. Do read
more about Mollies here:
Molly skin lesions 10/23/08
I would like to express my gratitude for the invaluable resource
you provide. My fish also thank you for improving their quality
<Thanks for the kind words.>
I have a cycled 20ga brackish tank with a whisper EX30 filter, a
heater, a bubble stone, wisteria, Amazon sword, and horn-wort
<I'm amazed these plants are growing at SG 1.008! Pretty
darn salty for most freshwater plants. Are you sure your
hydrometer is accurate or you're using it right? Usually
freshwater plants struggle above SG 1.005, though there are
The substrate is 5 cm deep fine gravel. I have been testing the
water daily with an API freshwater kit and an Instant Ocean
hydrometer since adding two Nerite snails and three creamsicle
lyre-tail mollies (1 male, 2 females) 2 weeks ago. As expected I
needed to change the water daily for the first week to keep
nitrite levels under control while the biological filter caught
up with the new load.
<Nitrite is toxic to Mollies in freshwater tanks, but
seemingly much less so in brackish/marine conditions. That's
why Mollies can be used to cycle marine aquaria, something that
would kill Mollies under freshwater conditions.>
My values are S.G. 1.008, salinity 10 ppt, ammonia = 0, nitrite =
0.25mg/L(before changes), nitrate = 2.5 mg/L(before changes), pH
= 7.8, temp = 79 F.
<Apart from the nitrite, this is all fine. SG 1.008 is
actually around 13 grammes of marine salt mix per litre. In all
fairness, this is far more salt than Mollies need to be happy,
and SG 1.003-1.005 (6-9 grammes per litre) is ample. Your plants
should do better at a reduced salinity, and you'll also save
Thus far all three fish are active, gregarious, and voracious.
They even take food from my hand. I am feeding ~50% Spirulina
flakes, ~25% TetraMin flakes, ~ 25% freeze dried bloodworms,
freeze dried brine shrimp. Both females appear to be quite gravid
and I have a 10 ga tank started cycling for the fry.
I have attached a picture of one of the females showing a
distressing looking (to me at least) opaque lesion on her dorsum
ranging cranially from her lips to the caudal aspect of the base
of her dorsal fin.
<From the photo I can't really see much: but it
doesn't look obviously damaged. I'd actually imagine this
is simply its colouration, and not be too worried.>
To me it resembles the outside of a powdered donut though not
entirely white, looking rather flattish and dimpled as opposed to
cottony or stringy. The other female has a much smaller area also
on her dorsal aspect but it is less pronounced and encompasses a
smaller area cranial to her dorsal fin.
<Hmm... do honestly need a sharper image to say anything
I have attached a picture of the worst of the two afflicted fish
with the hope of obtaining a tentative diagnosis. My fear is that
I am dealing with columnaris or a pernicious fungal infection. I
do have some background in veterinary medicine (companion animal
emergency/critical care) but no practical experience with aquatic
critters and I am stumped.
<Well, fungus is pretty rare in brackish water tanks. Finrot
and Columnaris are both bacterial infections, but neither is
obviously the case here. While you might treat the tank with, for
example Maracyn, do take care whatever you use is safe with
Nerite snails. Copper-based medications (most anything that turns
the water blue or green) can be lethal to snails.>
I don't want to give arbitrary medications based on the
somewhat dubious advice of my LFS. Can you tell from the picture
what may be going on and advise accordingly?
<Unfortunately can't diagnose the problem, if any, from
these photos. Because both fish have similarly placed and
coloured "lesions" I'd actually suggest that
you're looking at a distinctive colouration of this breed of
fish. If the fish are otherwise healthy, and the mouth and fins
in particular look clean, I'd be fairly positive about their
health, and basically sit back and observe for the time being.
But I can't be 100% without a sharper photo.>
|Re: Molly skin lesions
Thanks for your response. Sorry the resolution was so poor. Maybe
this one is better? (I hope...)
<Yes, certainly sharper. But still not seeing anything obviously
"wrong". Yes, there is a white pattern leading back from
behind (its) right eye over the shoulder and along the dorsal
surface towards the right side of the dorsal fin. But this
isn't obviously (to me) a disease as such. One complicating
factor is that many "fancy" varieties of fish are
extremely inbred, and you can get all sorts of genetic
abnormalities. So before diagnosing Finrot or Lymphocystis or
whatever, I'd be looking to see if these are merely aberrantly
coloured scales or something along those lines. I'd also check
to see that scales haven't fallen off. That happens sometimes
for no particular reason, though it is more often a sign of
fighting or physical damage, e.g., by rough handling or even
(failed) predation. Conversely, I'd be looking out for clear
signs of ill health, specifically loss of appetite and/or shyness.
Livebearers seem (in my experience) to become very withdrawn when
ill, and that's often the first sign something is
I will take a water sample to the office with me today and recheck
the S.G. on one of our refractometers to compare results.
<Have a sneaking suspicion you will be surprised. Swing-arm
hydrometers are notoriously inaccurate, perhaps because of friction
around the pivot, especially given a build-up of lime or salt. I
prefer to weigh out the salt mix, and then use a floating
hydrometer to double check the specific gravity. If you haven't
tried it out, download my "Brack Calc" tool to see the
relationship between salinity, specific gravity, and water
Thank you so much.
<Happy to help. Cheers, Neale.>
Dalmatian Molly is sick....I think (Mollienesia; the
I have a 6mos old 10gal tank, water temp stays at 76 F, hardness
180ppm, nitrates ~10ppm, nitrites ~0-1ppm, KH at 50ppm and PH
<Way, way too soft and acidic for Mollies. Do understand that
Mollies will not, repeat WILL NOT, tolerate anything other than rock
hard, alkaline water. We're talking pH 7.5-8.5, 15+ degrees dH.
Arguably -- and it's a VERY strong argument -- they are best kept
in slightly brackish water, around SG 1.003 to 1.005. Moreover, they
are VERY INTOLERANT of nitrite, so if you can detect ammonia or
nitrite, and you aren't keeping them in brackish/marine conditions,
that's as good as signing a Death Warrant. In any case, the tank is
too small for Mollies. Even a tank 3 times this big would be marginal.
They are NOT easy fish to keep, hence the constant flood of messages to
WWM about sick Mollies!
We use an AquaClear 3 stage power filter. We have one each of the
following; neon tetra, white cloud, sunburst, Dalmatian molly, algae
<One Neon? One Minnow? These are SCHOOLING fish, and MUST be kept in
groups of six or more. Please please please read up on the needs of
your fish. I wonder what the "algae eater" is? If either
Pterygoplichthys ("Plec") or Gyrinocheilus ("Chinese
Algae Eater") you will live to regret this purchase. Both are huge
animals, and Gyrinocheilus famous for being nasty, aggressive fish when
The molly was the last fish we added. At that time the water clear, we
added the molly..loved the
algae on the shells. the a small algae bloom appeared. Added Algaefix
and within 3 days the water was crystal clear and ALL fish were
<Algae is not a problem as such. Do understand it's TELLING you
something about the tank. Don't "fix" the algae, but
instead concentrate on what might be amiss. Is the tank getting direct
sunlight? Is the water stagnant? Are there too many fish?>
We recently moved (next door) so I took the tank down between a half
and 2/3, so I could carry it over. Then refilled the tank. Added a
little aqua plus which we used when we originally setup the tank. Since
the move a very large algae bloom began taking over the tank, green
algae. I added Algaefix again. I have noticed though when I add algae
fix the molly becomes unhappy and camps at the bottom of the tank.
<Algae is what Mollies eat. They like it. Indeed, they're
healthier fed on algae than flake! Besides, anything poisonous to algae
will, at best, cause conditions to decline as the dead algae decays. At
worst, the Algicide will stress your plants and irritate your fish.
There is NO GOOD REASON to use algae killing medications, and plenty of
excellent reasons not to.>
So rather than keep up those treatments I have been doing weekly 25%
water changes and cleaning the filter each time. The molly seems to
like the water adds, very active.
<Yes; they like clean water. Between water changes the water quality
drops, and the Molly gets stressed. Do a water change, and he peps
But when I treat the algae it seems to dislike it. This has been going
on now for a month. This past weekend I decided to do about a 30-40%
water change, tank was VERY cloudy with algae. I also added cycle to
the tank to try and address any issue with the bacterial cycle. This
was about 3 days ago. Today the molly is staying at the bottom and
trying to lay to it's side, when it begins to tip is catches itself
and tries to resettle again, sometimes it goes all the way on its side,
but rights itself each time if it begins to drift upwards. I also
notice it occasionally tremors as it camps on the bottom trying to get
<This is something akin to "the Shimmies", and a VERY good
sign that your Molly is not healthy.>
All the other fish are very happy, except the molly. The water is still
cloudy but much reduced. I changed the location of the tank. less
sunlight exposure and leaving the light off most the time...Bottom line
I don't know what's going on..very new to this and could use
Cycle, Algaefix and Aqua plus are the only chemicals I have used.
<Lay off the chemicals, and hit some books
We use TetraColor tropical flakes as their food...
<Mollies are herbivores and need algae-based flake foods. In any
case, colour enhancing foods are much misunderstood and best ignored in
favour of varied, balanced diet.>
Thanks in advance for any help!!!!
<Hope this helps! Please review in particular: diet, water
chemistry, water quality. Maintain your Molly in a tank offering what
this species need, and he should be fine. At the moment, things look
gloomy. Cheers, Neale.>