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FAQs on the Molly Health/Disease 9

Related 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 10, Molly Health 11,
FAQs on Molly Disease by Category: Nutritional (e.g. HLLE), Social, Infectious (Virus, Bacterial, Fungal), Parasitic (Ich, Velvet...), Genetic, Treatments
FAQs on Molly Reproduction/Breeding
Molly Reproduction 1, Molly Reproduction 2, Molly Reproduction 3,

One day I saw that my Molly had a white line growing on the top of its head       3/30/16
and I'm worried cause it wasn't there before. I have attached a picture of my Molly and the white line
<Mmm; this white line looks to be some sort of physical injury... perhaps the fish jumped or swam into something that scratched it. Is your water hard and alkaline? Do you add a modicum of aquarium salt? IF your water conditions are propitious and you're feeding your fishes well, this issue will likely heal itself in time. I would not specifically add some sort of medicine/s here, as they're more likely to cause trouble than cure.
Bob Fenner>

re:       3/30/16
There is a small amount of aquarium salt in the water my water is fine, said the lady at the pet store, the only thing that's wrong is my ammonia is high
<Ammonia is deadly toxic. READ here:
and the linked files above. BobF>
re: Keep Reading!       3/30/16

Would that cause my Molly's wound not to heal? Or cause it to grow?
Neale to the rescue!       3/30/16

One day I saw that my Molly had a white line growing on the top of its head and I'm worried cause it wasn't there before. I have attached a picture of my Molly and the white line
<Very odd. The photo isn't sharp enough or close enough to see exactly what's going on. Is it that some of the scales are simply white? This sort of colour change can happen and isn't a health issue as such. Or is there something white, almost like paint, across the back of the fish? This is very commonly seen on Black Mollies and other dark-coloured Mollies when they produce extra mucous. This is usually what happens when they're stressed or irritated by something, either an early bacterial infection or exposure to the wrong environmental conditions. I'm going to direct you to some reading:
Mollies are prone to Finrot and fungal infections when kept in plain freshwater. In brackish water they're a lot tougher, and by brackish, I'm talking something like 5-6 gram/litre (3-4 teaspoons of marine aquarium salt mix per US gallon). Although brackish conditions aren't essential, they help. If that isn't an option, then do make sure the water is very hard (15+ degrees dH) and relatively warm (25-28 C) and above all else keep nitrate as low as practical (20 mg/l or less). Naturally, ammonia and nitrite levels should be zero. Cheers, Neale.>
re:       3/30/16

There is a small amount of aquarium salt in the water my water is fine, said the lady at the pet store, the only thing that's wrong is my ammonia is high
<I'd love to know what the "lady in the pet store" means by the word "fine" if your water has high ammonia! Let's be clear, subjective interpretations of water chemistry and quality are about as useful to us as you telling your doctor that "you've got an owie on your booboo". So please, write back when you have some actual numbers. To recap, as always with fish, and nitrite must be zero. If they're not, then stop feeding and review the aquarium. Non-zero ammonia and nitrite imply three things: overstocking, overfeeding, and/or insufficient filtration. This last one is key, and you can have insufficient filtration because the filter is too small, because you are not maintaining it properly, or because the filter hasn't had the 6-8 weeks it needs to mature. Review, and act accordingly. As for the other
water parameters, in freshwater conditions you need low nitrate (<20 mg/l);
high pH (7.5-8.5); and high hardness (15+ dH). In brackish conditions Mollies are less demanding, but that will of course limit your choices of tankmates. Nonetheless, they're commercially reared and bred in brackish water for precisely this reason, and if you're specialising in Mollies, adding 5-6 gram/litre marine aquarium salt mix (not tonic/aquarium salt) will massively simplify your fishkeeping experience. Cheers, Neale.>
re:       3/30/16

Would that cause my Molly's wound not to heal? Or cause it to grow?
<Dissolved ammonia is to fish what Cholera bacteria in drinking water is to humans: deadly, and able to cause all kinds of problems. So when people say "a trace of ammonia" is in their fish tank and think that's fine, to me
that's liking offering someone a bottle of mineral water with a "trace of Cholera". Not nice, huh? Cheers, Neale.>

re: Just to update you on my molly.        4/7/16
I did take all of my fish out of the tank
temporarily into another fish tank that I have. I changed the water and tested it one more time with master test kit, which is a drop test. My ammonia was 4.0ppm... yea that isn't a little high no wonder why my fish were dying and my Molly wasn't healing.
<I agree!!!>

My Molly apparently scratched it's head trying to get into my tiki head, I guess she learned that she's to big for a few things haha. So now my fish is all healed and my aquarium is back to normal, meaning having an ammonia level of 0, I am also feeding my, now 3 fish, once every other day and I'm also keeping a close eye on all their levels. And I'm thankful to day that I'm not going to that petstore ever again, and I'm also doing a lot more research into everything that I do and every fish that I get. :)
<Not saying avoid your local pet store, but do keep an open mind, and as the Russians say, "trust, but verify". Double check what they tell you against a trusted book or website. Obviously this one's good, but there are others I wholeheartedly recommended. TFH, FishChannel, SeriouslyFish, PlanetCatfish, Loaches.com, ThePufferForum.com ... all good sources of info and accessible to all.>
you will most definitely hear from me again this is the best help that I've ever found.
<Thanks for the kind words. Neale.>

Aquarium question. Molly health, using WWM      12/27/15
I have a 55 gal. freshwater aquarium. I do 20-30% water changes each week, and the tank is fairly heavily planted. Lately I have noticed that a few of my VERY pregnant mollies are shimmying on the sand substrate. They are not giving birth. Otherwise they seem to be swimming normally, eating. What can I do to help them.
<Mmm; all Molly species and hybrids require hard, alkaline water.... many only do well with considerable sea salt in their water>
My ammonia and nitrite readings are at 0. Ph is about 6.5 instead of 7.
<Mmm; too low>
This is pretty standard (putting droplets into test tubes of aquarium water.)
Then I got a test-strip, which also tests GH and KH, which I’d never tested before. GH and KH are almost 0.
This is too low? How do I change it? Could its be causing the problem with the mollies?
<Yes, reading, yes>
I was told to add finely ground egg-shell to raise the hardness of the water,
<.... no>
which I did, but I really didn’t notice any change. I was also told to add some food grade montmorillinite clay, which I did and only got cloudy water.
Other tank mates: 12 or so Cory catfish, 1 loach, snails, 5 Danios, 4 cloud mtn. minnows, 2 swordtails.
I would be SO APPRECIATIVE of any help.
<Start here: http://www.wetwebmedia.com/fwsubwebindex/mollies.htm
and the linked files above. Do you need help searching on WWM for Neale's articles on water hardness?
Bob Fenner.>
Aquarium question      /Neale      12/27/15

I have a 55 gal. freshwater aquarium. I do 20-30% water changes each week, and the tank is fairly heavily planted. Lately I have noticed that a few of my VERY pregnant mollies are shimmying on the sand substrate. They are not giving birth. Otherwise they seem to be swimming normally, eating. What can I do to help them.
<Will direct you to some reading...
Mollies are very finicky about water chemistry. If not completely brackish water fish per se, they certainly need high hardness and pH to do well, and in freshwater tanks, minimal nitrate (as well as zero ammonia and nitrite).>
My ammonia and nitrite readings are at 0. Ph is about 6.5 instead of 7.
<Well, here's your problem.>
This is pretty standard (putting droplets into test tubes of aquarium water.) Then I got a test-strip, which also tests GH and KH, which I’d never tested before. GH and KH are almost 0. This is too low? How do I change it? Could its be causing the problem with the mollies?
<Again, let's direct you to some reading:
Scroll down to the Rift Valley Salt Mix. Use this, about half dose if you've got other fish in the tank that aren't livebearers. If just livebearers (Guppies, Platies, Swordtails as well as Mollies) then feel free to use the full dose.>
I was told to add finely ground egg-shell to raise the hardness of the water, which I did, but I really didn’t notice any change.
<Indeed; adding egg shells is fairly pointless.>
I was also told to add some food grade montmorillinite clay, which I did and only got cloudy water. Other tank mates: 12 or so Cory catfish, 1 loach, snails, 5 Danios, 4 cloud mtn. minnows, 2 swordtails.
I would be SO APPRECIATIVE of any help.
<Welcome. Neale.>
SandraRe: Aquarium question      12/29/15
Hello Neale and Bob,
Thank you for your prompt reply. I am reading the articles.
<Glad to help.>
I am doing a 20% water change, and amongst the water I am adding will be a 5 gal. bucket as per your recommendation, namely:
Per 5 US gallons (20 litres) add the following amounts of each
* 1 teaspoon baking soda (sodium bicarbonate)
* 1 tablespoon Epsom salt (magnesium sulfate)
* 1 teaspoon marine salt mix (sodium chloride + trace elements)
So a good plan would be to do this at every water change? ( I change weekly)
<Yes; don't change all the water at once, because suddenly changing the water chemistry will cause entirely new problems for your aquarium. I'd also remind you that if there are non-livebearers in the aquarium, don't
use the full dose, half the dose instead. So per 5 gallons, 0.5 teaspoons baking soda, 0.5 tablespoon Epsom salt, etc.>
I used a test strip on my water from the tap and found that it is on the soft side.
<Yes; do also feel free to tweak the "recipe" as given above. Epsom salt provides the general hardness, so using a bit less will lower the general hardness. Baking soda provides the carbonate hardness (and raises the pH as a bonus) so if these go too high, reduce the baking soda amount. The salt is optional, but adds a few trace elements useful for hard water fish. Would recommend making up a test bucket first, then repeating with different amounts of the chemicals until you get something "just right".
Write down what you did, and stick with it. As a benchmark, for a mixed community that happens to include Mollies, something like 10-15 degrees dH general hardness and a pH of 7.5 is about right. If you're just keeping Mollies and other livebearers, then you can go higher, 20 degrees dH, pH 8, and you'll see Mollies really perk up in such conditions. You can always skip everything but the salt, and use that to create brackish conditions, which Mollies love, but that limits your options in terms of tankmates and plants, so isn't the obvious first choice for most folks.>
One additional question is why the ground eggshell is not appropriate, since eggshell is calcium carbonate and calcium carbonate, according to the article, adds to water hardness.
<Egg shell has a poor surface area to volume ratio, so dissolves too slowly to make any meaningful changes to water chemistry. It's as you learned in school: the finer the particles, the quicker they dissolve. It's even worse in aquaria because over time bacteria and algae coat the eggshell, slowing down dissolving even more.>
Again, thanks for the helpful comments!
<Welcome. Neale.>
Re: Aquarium question      12/29/15
Again, thank you, SUPER HELPFUL. I am printing it out so I can save it for future reference.
One last ? regarding the eggshell. (It’s really not that I’m obsessed with this, I just want to know.) The eggshell I’m using has been baked to make it fragile, and then crushed to a powder in my food processor. Is that fine enough, or should I just forget it?
<Powder is better, for sure. But it's just another random variable. Put it this way. When you add Epsom salt and baking powder to water they dissolve quickly, and within a few minutes you can do a water test and trust the results are accurate. Job done. Add water conditioner, and your water is ready to use. Now, if you add things that dissolve slowly, whether egg shells, lumps of limestone, coral sand or whatever, you have no idea at all what affect they have on water chemistry over the following days and weeks. If your fish are ALL true hard water lovers, like Mollies (and other livebearers) or brackish water fish, then for sure, you can add some of this stuff to the tank and any impact it has will be positive. Since the rate they dissolve depends on pH, once the pH climbs up to around 8.2, they stop dissolving, which is too high for community fish but just fine for livebearers and brackish water species. Since your tank contains other fish, such as Corydoras, this kind of pH level isn't what you want, so adding stuff to the tank isn't recommended. Whereas, adding dissolving powders to each new batch of water is fine because once done the pH stays more or less steady at whatever it is you measured in the bucket. If you get pH 7.6, say, in the bucket, by the time you add it to the aquarium that's about the sort of pH it should remain at (some slight change, usually downwards, is not uncommon). Make sense?>
Thanks again,
<Cheers, Neale.>
Re: Aquarium question

Neale, Thank you again. I get the eggshell picture finally.
I re-tested my water, and hardness and pH both are up to the correct levels. I never thought to see that happen. I had even bought some kind of pH stabilizer at the shop, but the results were minimal.
<Those liquid pH-up and pH-down potions are really best thought of us buffers. You add them once you've adjusted the water chemistry to prevent any further changes. Useful if you're keeping delicate fish. But there are commercial "Rift Valley" or "cichlid" buffer salts that work a lot like the mix we've made from Epsom salt, etc., but are ready mixed in the right amounts. So if you value convenience, and can remember to half the dose stated on the packaging, they should work just fine.>
A number of years ago I over-wintered a few koi in a tank in the house, an emergency measure. Someone recommended baking soda as a way to keep the water smelling fresher, they were so messy. I did that every week as I cleaned the tank. But just now it dawns on me that that is why the snails which shared the tank also had such strong shells. You see, it was some deterioration and loss of luster on the snails’ shells now that first alerted me to the fact that the hardness was not where it should be. My regular test kit doesn’t test for hardness, and I only recently understood that it was a “thing.”
<Ah, yes, very definitely a thing. In fact I'd say more important than pH. Everyone gravitates to pH when they start out: it seems so simple. pH 6 for acidic, pH 7 for neutral, pH 8 for alkaline water conditions. All stuff you learned in school. Hardness is complicated. Two different kinds, literally dozens of different units, from German degrees to Clark degrees to parts per million to milligrams per litre! But any test kit should come with a card or leaflet that at the very least explains the units used in terms of being "soft", "medium soft", "medium hard", "hard" and "very hard" -- or words to that effect. For Mollies, you want "medium hard" to "very hard".>
So not just the mollies, but also the snails should be happier.
<Yes indeed.>
Thanks again.
<Most welcome. Neale.>

Sick Molly's; no data, rdg.     10/7/15
I am not sure if I am in the right area but I need some help my water is 0.05
<.... is this specific gravity? If so; likely you mean 1.005. What salt/s did you use here?>
I have mollies with some weird symptoms started out like dry looking patches and now looks like this orange one she is the only one that looks like this they start out like the balloon Molly and progresses there are only 3 I can see that look like this but only the orange that looks this bad I found 2 baby's with what looks like little holes in there head and one baby his eye was white and pooped out I believe
<... need more data; re water quality, system, maintenance, feeding, history of the system. Let's have you read here:
and the linked files above.... for input, and to grant you an idea of what sorts of info. we're looking for. Bob Fenner>

Re: Sick Molly's    10/7/15

Sorry I am sick and not functioning on all cylinders myself it is specific gravity and it is 1.005
<Mmm; if you had other livestock.... than shown in your pix; I might well be raising the "saltiness" here>
I use marine salt by instant ocean
<Ah good>
tank is over a year old and cycled I use SeaChem stability and ammonia alert it's o it only measures free ammonia but I also checked with a ammonia tube tester it shows zero I use a biological cascade 1000. I do 15% water changes weekly. I test with high range ph test kit it is 7.5
Nitrite is 0 nitrate is 5.0
I have had issues with phosphates getting up between 1.0 and 2.0
<Meh; not to worry>
but use a phosphate remover, also by SeaChem. I only have 1 live moss ball in the tank it has really good oxygenation I have 1 Plato
<Pupil of Aristotle?>
1 shrimp a few zerite snails
<Zerite then>
it's a 45 gallon corner tank and 4 adult female mollies, 6 juveniles and honestly could not tell you how many babies my levels were fine so didn't worry about it I want to give them away but can't till I know what's up in this tank I got Molly's all at once never added any more snails were added after and shrimp feed omega one twice daily micro pellets for babies or crush the omega one in a pill crusher I do both I have city water, use aqua safe to remove chlorine my temp is 80.2. I have used Metronidazole in the water it was by apI twice
<Don't keep putting this in: Toxic>
48 hour intervals then I started giving mixed 1/8 tsp api to 1/2 tbs omega one soaked in 1/2 tbs water for 30 min now I have started using life guard
<For what? What for?>
while waiting to find out if anything can be done.
<...> really <...>
I have not seen anything like the pics I have sent you, do you have any idea what this could be I believe my mollies came with whirling disease I had the whirled for a year I euthanized her when she finally stopped eating I kept her in a floating baby nursery with a nylon bottom lost a lot of babies to this disease it finally stopped I hope.
Colleen ^>,<^
<.... wish I had a microscope nearby there.... Do you have another system you can move just the mollies to; jack up the salinity? BobF>

Re: Sick Molly's     10/8/15
I have them in a separate quarantine tank just has the 2 mollies a baby Molly that is twirling but has since stopped a baby with a white eye and 2 small babies with what looks like a tiny whole in there head nothing else in this 15 gallon quarantine tank
Colleen ^>,<^
<Do see my previous message, and Bob's; do also read:
Mollies aren't difficult to keep in (very) hard or (even slightly) brackish water, but are endlessly delicate if kept otherwise. Sensitive to crowding, nitrate, cold, and various other factors. Cheers, Neale.>

Re: Sick Molly's      10/9/15
Well I thought I read everything but got nothing I didn't already know my levels are fine in everything,
<Please don't tell me this. It's no use to me. What, specifically, did you measure? What numbers did you get?
Many hobbyists think their tank is "fine" but they're not. By "everything" do you include salinity? pH? Hardness? Nitrate?>
but I didn't read anything that you thought it might be or what to try I am old and have worked really hard to help them they came sick with clamped fins in fresh water of course, I have read a lot on that site you sent a long time ago, if you sent something that might help I must have missed, I think I am done, euthanize the lot 9 separate tanks because of all these
babies, but they all come initially from the same tank,
<Seems a bit extreme. Let's review. Mollies are most sensitive to environmental issues. Specifically, coldness (keep them at 25-28 C if possible); acidity (keep them at pH 7-8.5); and hardness, most easily dealt with by keeping them in brackish water, around a teaspoon of salt per litre (about 3-4 per US gallon) being about right. Farmed Mollies can suffer from
some "catchy" diseases, with Camallanus worms and "Slime Disease" (also known as Costia) being the two most difficult ones to medicate against. By contrast, while Fungus and Whitespot do occur, as does Velvet, all these are easily treated. But do remember to remove carbon from the filter before using medicines. Finally, using salt often helps moderate or even eliminate diseases.>
I feel I can't find new homes till I know what's going on. So it's time to euthanize unless I can come up with something else to try. Maybe I missed something I will go back and look but I just saw the one message and it was hard to follow.
Colleen ^>,<^
<Hmm... not sure this is difficult to read, and would start here:
Most fish health problems are environmental, especially where many fish are sick at the same time. Review conditions, or at least TELL ME the values on your test kit, and we can take it from there. Cheers, Neale.>

Re: Sick Molly's       10/10/15
I told you all the values when I started messaging you about the mollies I use specific gravity to test their saline,1.005 I have sent numerous messages in the past few days with pictures and gave you all the values in the tank, how I feed what I feed and there not all sick and only this fish looks like this and I felt was getting any info on meds or how to help so euthanized today
<May have sent this information before Colleen, but there are several of us who help out at WWM, and I don't recall reading a message with those values. Try to imagine what it's like for us. We get hundreds of messages a week, and simply can't keep track of every bit of information. So when someone says they sent a message to us last week with a piece of
information in it, that's a lot less helpful to us than resending that piece of information in a new email. Just the way it works, Colleen, I'm afraid. We're volunteers, we're offering a free service, and what we're trying to do is incredibly difficult. Imagine a doctor diagnosing a human illness by email. That's the situation here. If your fish tank was in front of us, and we could do all the test kits immediately, that'd be great. But we aren't with you, and we rely on you to do the tests. If you can't send test kit information to us, you're basically asking us to figure something out with 90% of the important information missing. I'm not exaggerating there. Water quality and water chemistry are the two main reasons fish sicken and die. All the other reasons are rare.>
These are some better close ups I am old and not feeling well so I just can't go through all the info again I am sure if you go back and read you will find what you need,
<Indeed you had, and with a bit of effort I've found them. pH 7.5; fine.
But no information on hardness. Let's assume it's adequate. Specific gravity 1.005 is excellent. Nitrite you say is zero, nitrate 5.0. This latter value is very low, which is good, but I'm normally skeptical of such low nitrate values. Why? Because most urban and suburban water supplies are well over 20 mg/l nitrate, often 40 mg/l. Certainly in England where I am!
But if you're out in the countryside somewhere and use well water or something with very low nitrate, then your test reading might be accurate.
Nonetheless, keep an open mind about this nitrate value. Test kits don't always measure accurately, or may be difficult to read.>
and to be honest you guys are who ever I have been messaging with have been snappy, the rolling eye comment because I told you I was using life guard," because I did not know what else to do while I was waiting for information"!!!!!! And you asked why I was treating with life guard, then did that eye comment thing.
<Hmm... I don't think these comments came from me. But in any case, we're sometimes snappy because we've got a lot of sick fish questions to get through, and it can be frustrating sometimes when we're dealing with willful ignorance -- not in your case, but does happen rather often, where people hang on to ideas (like Bettas can live in unheated bowls) because they
prefer ignorance (and fish dying, only to be replaced a week later) from accepting they're wrong (and spending more money). As folks who like pet fish and turtles, what we mostly help with here, we get a bit worn down by this at times, and it may become obvious if we're a little short at times.
Don't take it personally. If we were really mean people, we'd not be doing this for free, and we'd have just ignored you. Judge a man by his actions rather than his words, is what I'm saying.>
After I told you why I was using it. I am not a expert but do care about my fish, have worked very hard to help them I have purchased more and more tanks because of the crowding, I am just euthanizing any sick fish I see, I have tried for a year to get a straight answer and can't so I am done,
<Sometimes there just isn't a single straight answer. Mollies are plagued with problems in the US especially, kind of how Neons and Guppies are here in the UK. I guess breeding a fish to a price point rather than a quality has been the cause. But in any case, some problems are difficult to diagnose. Your fish may well have had more than one problem, and while I
suspect the blisters (which I hadn't seen clearly before) are from exposure to some sort of toxin, it's hard to say what. Blisters aren't normally caused by common disease organisms, or genetics, but tend to be environmental, sometimes mediated through a viral infection (such as Lymphocystis, which is untreatable but not normally fatal, and often clears
up after some months, even years). Even if you think the water is 100% perfect, it almost certainly wasn't. Copper perhaps, or something airborne like paint fumes might have been getting into the water. It's really hard to say. On the up side, since this isn't likely to be contagious or genetic, any healthy Mollies should remain healthy if their environment is good. Review, as previously discussed, and act accordingly. Think about what might have been getting into the water, and perhaps swap your current water conditioner for something that specifically neutralises copper, ammonia and heavy metals. Relocate the tank if it's somewhere near a source of fumes, and perhaps use carbon in the filter (not normally a fan) and see if that helps (will need replacing every couple of weeks though). Carbon has the useful trait of removing certain dissolved chemicals from the water that normal filtration does not.>
maybe you just did not get my e-mails and all the info and pics I sent you, thank you for your time have a nice Day.
<There's no single answer here, which I'm sure is frustrating. But much to think about. Cheers, Neale.>

Mollies dying; diag., trtmt.s f'      9/1/15
I apologize I hit send before checking my grammar and spelling, as I am messaging from my phone...I will correct...
<Not a problem.>
Dear WWM Crew,
I noticed you had another person named Jace email you back in March of 2011 with similar issue that has not been solved and was wondering if you have any more insight now that some time has passed... I had 2 white mollies, 2 black mollies, 1 orange balloon sailfin molly and 1 gold panda molly in a 20 gallon cycled tank (fish purchased approx. 1 month ago), frequent water changes done (25-40% per wk),with regular testing, 0 ammonia, 0 nitrites and 5 nitrates (no spikes during this recent time) the mollies came from brackish water so I have kept this environment for them.
<Can you tell me how much salt you're adding? Brackish water suitable for Mollies would be something like 5 gram/litre (0.65 oz/US gallon). That gets you a specific gravity of 1.002 at 25 C/77 F. You can use digital scales at home to work out how much you'd want to add per bucket. For a 3 gallon bucket for example, that'd be 3 x 0.65 = 1.95, close enough to 2, oz per bucket. Make sense? Once you've measured it out you can use teaspoons and see how many teaspoons there are in that quantity of salt. It's about 5 teaspoons per 1 oz of salt, more or less, so we're talking about 2 x 5 =10 teaspoons per 3 gallon bucket. With me so far? Mollies will actually do even better at higher salinities, and even doubling this amount of salt
could be worthwhile if your aquarium is just Mollies and plastic plants/ornaments (real plants and most other fish won't be so keen).>
Anyhow, first I noticed definite Ich symptoms - as the black mollies, orange molly and panda molly were COVERED in white dots like salt grains (couldn't quite see any on the white mollies). I raised the temp to 86 degrees to speed up life cycle and increased the salt in the water to 3tsp per gallon
<3 x 6 gram per US gallon... 18 gram/US gallon... 18 gram/3.8 litres... 4.7 gram/litre... yes, that should certainly kill of Whitespot and Velvet.>
when white spots disappeared to kill the ich the natural way (without meds)...
<Salt is a medication... in some situations far more harmful than, say, antibiotics.>
Now, before the white spots disappeared, 1 white molly's tail fin just disappeared (frayed down the body) and then back half of her body started to look fuzzy and she just kept spiraling around tank so I euthanized her.
The next day, the 2nd white molly's mouth was swollen open & just started crashing in to the gravel upside down, gills heaving and could not move so I euthanized her also.
<Not good.>
A few days later, the orange balloon molly's lips looked the same, she crashed and died just like the white molly! So, I assumed the Ich overtook the fish because this all occurred before the white spots fell off any of the fish and the other fish were COVERED in salt grains so it just made sense.
<Possibly, but I'd be wondering if Velvet or even Costia is the issue here.
Costia is the old name for Ichthyobodo, and you'll see both names in aquarium books, though Costia (or "Slime Disease") are more often seen on medications. In any event, like Whitespot we're talking about a microscopic protozoan that latches onto the skin of the fish and causes damage. Costia does seem to become more lethal more quickly than Whitespot or Velvet.
Commonest symptom is the appearance of off-white patches (rather than the discrete salt grains of Whitespot or icing sugar/golden sheen of Velvet).
It's more difficult to treat than Whitespot, though some medications will treat both. Brackish water works well against it though, as do 2-20 minute seawater dips (35 gram/litre). Mollies tolerate seawater dips extremely well, so this is a useful approach. I'm mentioning Costia here because it's a bit of plague among Mollies, notoriously obvious on Black Mollies because of their colour, often as greyish patches on the face and flanks.>
So after a couple days of raising the heat slowly, the white spots all disappeared and I started the salt treatment (to kill the free floating Ich), when all of the sudden (now this is when it gets exactly the same as the email you received in 2011 that I found on your site from Jace that had no resolution or real answer) the 2 black mollies started hanging around the filter intake and the heater near the surface (but not gasping), with their tails down as if their tails were paralyzed (drooping) and if they swam under the waterfall from the filter,
<This is the famous "Shimmies" when Mollies are stressed and unable to swim properly. It's called the Shimmies because initially the Mollies rock from side to side as they tread water, as if shimmying.>
they were forced into somersaults uncontrollably but then would buoy back up to the surface, tail down again. I also noticed their bowel movements were a long, clearish-white hair-like string (with intermittent white beads every so often).
<Interesting. Copious white faeces indicate excess mucous in the gut, which in turn often points towards parasitic infections, most notoriously, Hexamita.>
The next day, one black molly started crashing nose down into the gravel and could not swim or right itself (just as the white ones!) He stopped breathing and I noticed its anus was extremely white. Now the other black molly is still hanging near the surface with her tail down, obviously about to suffer the same fate! The only other one left is the gold panda molly and she seems fine! Again no parameters changed drastically ever during this time, and the only identifiable problem I saw was the Ich, but, as I said, it cleared up before these last 2 started crashing and they started displaying these unidentifiable symptoms that even your site said were strange (back in 2011)...so, I'm wondering if anyone has any ideas?
Any new knowledge on this? Could it be Ich AND something else?
<Easily. Whitespot/Ick is pretty much ubiquitous, but it's so easy to treat in its early stages it shouldn't ever be lethal. But it's also easy for fish to pick up other infections, and among livebearing fish, Camallanus worms, Hexamita infections, and something called Tetrahymena are all worth thinking about. Hexamita is treated by using Metronidazole, and is discussed elsewhere on WWM; use the Google search facility on the top of each page and you shouldn't have any trouble finding out about Metronidazole (often used alongside an antibiotic). Now, Tetrahymena is something less widely discussed. It is sometimes known as Guppy Disease.
Superficially similar to Whitespot in terms of symptoms but far more immediately lethal. To save me rewriting a bunch of stuff about this disease, let me direct you to a piece about this disease I wrote over at FishChannel:
The bottom line is that there are no effective cures, though a combination of anti-protozoan medication (Metronidazole for example) alongside elevated salinity (the higher, the better) may help.>
I forgot to mention all the fish were purchased together and introduced to the cycled tank at the same time (which I would never do again obviously!)
But I am very curious what this is and what to do now? I don't want to proceed ignorantly and subject any more fish to whatever this issue was!
Please help as I cannot bear to lose any more or have to euthanize; I am an avid animal lover and it's breaking my heart!!
Thank you!
<Hope this helps. Cheers, Neale.>
Re: Mollies dying        9/2/15

Thank you so much, I will look into all of this information!
<Glad to help and good luck. Neale.>

sick molly sucked into syphon       8/24/15
I'm so sad as I sucked my molly into my syphon for a second only on Saturday, but enough to cause real problems for her.
She turned red in her head area which has now gone back to normal but...she's been head downwards in the hospital tank ever since - can't seem to right herself. Tries to eat but not sure if she's managing.
Not sure if to euthanise her as she surely can't stay like this - I'm surprised she's still alive after 2 days. Hate to think she's suffering jay
<Fishes are very resilient; capable of healing from tremendous injuries. I would not give up hope.
Bob Fenner>
Re: sick molly sucked into syphon        9/6/15

so.......THANK YOU! for your advice! I left her in her hospital tank and very very nearly ended her days but every time I came close, she seemed to perk up a little. After 2 weeks she was still unbalanced but loving her food so I risked putting her bank into the tank. She's swimming around now like nothing ever happened! Thank goodness I waited...
I don't know how to post on your site, but if a fish every gets sucked into a syphon and seems at death's door, just to say that yes they can recover!
<Thank you for your upbeat report. Bob Fenner>

balloon molly with growth      5/17/15
I have a Dalmatian balloon molly with a growth behind its right fin.
<Ahh; see this in your pix...>
It looks like a solid mass, grayish green in color, consistently growing. I would say it has doubled in the past few weeks. Please see attached picture. I would appreciate any insight.
<Such growths are more and more common... tumorous; from various supposed causes... Narrowed genetic bottlenecking from so-much inbreeding, hybridising... perhaps water quality, nutritional input. Naught to do re treatments other than improving the environment and foods/feeding. Bob Fenner>

Re: balloon molly with growth        5/20/15
So basically she is going to die....and there isn't much I can do to help?
<Mmm; perhaps not die soon; but nothing that I'm aware of... other than experimental surgery, medicine use>
If I am understanding your last sentence correctly, you are saying there isn't much that can be done in regard to treatments for the condition.
However, I can monitor water quality and nutritional input....? Are there better fish foods than others?
<Yes; please see WWM re Molly feeding. BobF>

molly fish; hlth.       4/27/15
my molly fish acting strange, head in the gravel and other fish swimming around her is that sign of sickness or labor?
Sounds like "the Shimmies", which is almost always caused by an environment problem. Mollies are demanding fish, and delicate if kept in freshwater. Read:
Once you're done, it should be obvious what you'd doing wrong. Fix it, and your Molly stands a good chance of recovering. Just for once, it's nice to have an easy problem to diagnose at WWM! Cheers, Neale.>

Sudden Molly Death      2/16/15
Good evening WWM Crew!
<Hello Mark,>
I'm perplexed by the sudden death of one of my silver mollies, and by sudden, I mean within the time frame of me eating dinner. Prior to dinner she appeared to be just fine, and when I went to look in on the tank afterwards (approximately 25-minutes), I observed her lying dead in the aquarium.
Some background info: 20 gallon long tank, pH about 7.5, chlorine/chloramine 0,KH 120, GH 300, Ammonia 0, NO2 0, NO3 <5, temp 81.7 F. These parameters were measured just after I notice the dead molly.
<All sound fine. As always, mention must be made of the fact Mollies are generally hardier in tanks with a little salt added, even though they're not strictly brackish water fish. Your low nitrate levels are good though, and probably key to success when keeping them in freshwater tanks.>
The aquarium is planted, but I do not use any fertilizers or CO2. There is one other female silver molly and a male leopard-skin guppy in the tank.
All three fish were introduced together to the newly cycled tank on 01/17/15 and have been doing great, eating well, and showing no signs of distress or sickness. The two mollies were growing well. The one that suddenly died was a tad bit larger and was at the top of the pecking order in the tank. She was showing more and more signs of pregnancy and I was looking forward to a birth of fry any day (I even have another 20g long cycled and empty, set up just for the eventual fry).
The mollies and guppy were fed a pinch of tropical flake food this morning, and about 2 hours before the death I had blanched a baby spinach leaf and attached it to a feeding clip inside the tank where all 3 fish were voraciously nibbling away at it.
I have been feeding them a broad variety of foods, from tropical fish flakes, Spectrum Spirulina sinking pellets, peas, cucumber, zucchini, spinach, carrots, and one every 2-weeks or so some frozen brine shrimp as a treat.
Lying around the dead molly when I found her was 5-6 short lengths of bright green feces, presumably from stuffing herself with spinach. Did she somehow over feed herself to death? Is that possible?
<No more so than for any other animal.>
The other molly and guppy appear just fine, though a bit skittish with the sudden absence of the alpha female.
I performed a dissection on the dead molly, and she was indeed pregnant with what looked to be healthy fry and full belly of spinach. There were no unusual signs of illness.
<Sometimes problems with the embryos or actually giving birth can kill livebearers. Not common, but does happen. On the other hand, such fish usually show unusual amounts of bloating as the embryos decay, or else a prolapse around the vent.>
I've never raised mollies before and was hoping to learn of the species by raising some fry. Is this type of sudden molly death unheard of? Or, more likely, something I overlooked or did wrong?
<For now, I'd tip this towards "bad luck" but would still keep an open mind.>
Thanks in advance for your thoughts.
<Hmm... do read:
Thems is my thoughts!>
<Cheers, Neale.>

pop eye molly?     12/4/14
Hi all, sorry to bother you guys again. My roommate just got her tank and moved her fish from mine to hers so I'm back down to six fish in my tank. (with her fish there were eight fish and her two were several inches long) I came back from vacation and found two of my fish dead. I wasn't totally surprised since at the time the tank was very overcrowded and it was the smaller fish that had died. Well the issue was that the water was all yellowish brown from the fish being dead for a while in the tank (that what the pet store said) so I bought some clear water solution to help.
<... poor. CHANGE a good deal (like a quarter) of the water out every other day until it clears>

I treated the tank twice and afterwards the two fish were removed and put into another tank. One of my fish i believe is depressed as he and the male sailfin were pretty good buddies. I was feeding my fish this morning and I noticed that my female sailfin molly has her left eye bulging out slightly, just enough to notice and make her look weird. What can I do to help her?
<The above; water quality improvement, not "drops"... which will do nothing to improve it>

Also what can I do about my male's "depression" as he sits on the bottom since we moved the other fish.
<The exact same. READ on WWM re Molly Systems. Bob Fenner>
Re: pop eye molly?      12/4/14

Hi again. I just got back from class and my sailfin molly female (the one with both eyes slightly bulging) was sitting on the bottom. After a few minutes she got up and swam around and went right back to laying on the bottom. I just did a 50% water change and added some aquarium salt.
Is there anything else I can do to help with the eye bulging or will it go away on its own. I feel really bad for her. I plan on getting the water tested tomorrow to see what all the levels are. Another question is what is the best way to transport fish?
<Covered on WWM...>
I'm moving back home from college next week and I'm not sure how to move my fish. It is a 2 hour drive.
<Perhaps a bit of Epsom... see WWM re. BobF>

URGENT MOLLY HELP       12/5/14
I wrote to you guys the other day about my Sailfin female having PopEye on Wednesday. On Thursday I noticed that he eyes were back to normal (a very tiny amount of bulging but almost undetectable. Only noticed as she was right next to my Dalmatian molly male.) Today however, I noticed her eye was popping out again and her other eye had started to.
<When both eyes "pop" it's almost always some sort of environmental shortcoming. As always with Mollies, review the key basics: test carbonate hardness and pH (water needs to be hard and alkaline); test for nitrite or ammonia (water quality needs to be good); test for nitrate (this should be as low as practical). How much salt are you adding? With Mollies, brackish water is the ideal in the sense they tend to be much hardier and more resistant than in freshwater. To stress a point made many times here:
Mollies are not easy community fish, and can't be thrown into a planted tank or a regular community tank alongside soft water fish. They need very specific conditions. There's no medicine for Pop-eye as such, but the addition of Epsom Salt to the water (1 to 3 teaspoons per 5 gallons/20 litres) plus raising the temperature a couple of degrees can effect a cure provided the stress factors in the environment are fixed. Note that Platies will tolerate brackish water well (not less than 5-6 gram marine salt mix/litre in this situation) but soft water fish and most plants will not.
As I say though, you should only choose Mollies for tanks where you have the option of adding salt if needs be, and it sounds like you do.>
It got worse over the day so I put her in a small hospital/transport tank for several hours. Her eyes went back down quite a bit so I put her back.
Now all my fish are attacking her. My male molly and female balloon molly are chasing her everywhere along with my female bumblebee platy.
<Mollies are not sociable fish when kept in very small groups; often much better in large tanks and large numbers. Not a suitable species for tanks smaller than, realistically, 30 gallons, unless you keep just a singleton.
Sailfin Mollies in particular can get huge (15 cm/6 inches) under ideal conditions in the wild and not less than 10 cm/4 inches in aquaria, so anything less than 30 gallons is clearly unsuitable.>
I can't keep her in the "hospital" tank as it is really just a small animal carrier. She is now hiding in the barrel that I have which she has never gone in before. I'm worried about her. What can I do to help. I really like her as I was hoping to use her to start a small breeding operation (2 females and one male) of Sailfins. This is the picture of the hospital tank and her hiding from the others.
<Meantime do read:
And follow the links to Molly Disease and Molly System FAQs; the problems you are experiencing are very common and easily prevented. Cheers, Neale.>
URGENT MOLLY HELP.... the reading?        12/5/14

I wrote to you guys the other day about my Sailfin female having PopEye on Wednesday. On Thursday I noticed that he eyes were back to normal (a very tiny amount of bulging but almost undetectable.
<Excellent. As stated in my previous reply, environment is both the cause and cure of Pop-eye in such situations.>
Only noticed as she was right next to my Dalmatian molly male.) Today however, I noticed her eye was popping out again and her other eye had started to. It got worse over the day so I put her in a small hospital/transport tank for several hours. Her eyes went back down quite a bit so I put her back. Now all my fish are attacking her. My male molly and female balloon molly are chasing her everywhere along with my female bumblebee platy. I can't keep her in the "hospital" tank as it is really just a small animal carrier. She is now hiding in the barrel that I have which she has never gone in before. I'm worried about her. What can I do to help. I really like her as I was hoping to use her to start a small breeding operation (2 females and one male) of Sailfins. This is the picture of the hospital tank and her hiding from the others.
<Do read the other email. Write back if you need help. Cheers, Neale.>

Re: URGENT MOLLY HELP...  not what WWM is     12/7/14
Thanks . I'm going to get the water tested today. I will be moving home on
Friday (i live in a dorm) so I think a fresh start on the water will be
good for her. I do plan on getting a larger aquarium for these guys as I
want to put my Betta in the 10 gallon so he will be happier. I do have
aquarium salt in the tank currently and it does seem to help.
<For sure. "Aquarium salt" isn't the same thing as marine aquarium salt, and as/when you've finished the existing package of salt would be a good time to switch. Won't much affect cost, but marine aquarium salt raises not just salinity but hardness, pH and buffering capacity too -- all big plusses for the Molly aquarium.>
Thanks so much for all your guys help and for putting up with crazy me. As
this is my first time with an aquarium I tend to freak out when things go
<Nothing wrong with being concerned.>
Here is a picture of my tank.
<Looks nice!>
(three fish aren't in here as they are camera shy)I also got my water
tested and figured out the problem. Ammonia - 0.25 mg/l
<That's your problem right there. Ammonia above 0 is toxic, and Mollies are
ammonia-sensitive in freshwater tanks.>
Nitrite - 10.0 mg/L
<Lethal! I'm guessing you mean 1 mg/l since 10 mg/l would kill most fish
within hours. Together with non-zero ammonia, non-zero nitrite suggests
overstocking, overfeeding and/or under-filtration. Review, and act
accordingly. Short term: stop feeding, do daily water changes, and check
the filter is working/appropriate to this aquarium in terms of size,
Nitrate - 60-80 mg/L
pH - 8.4
Alkalinity - 300 mg/L
Chlorine/Chloramine 0 mg/L
<All fine. Cheers, Neale.>
Re: URGENT MOLLY HELP chatting, chatting... 
The pet store said it was at ten she was surprised and told me to do a
water change.
<A water change is an understatement! At 10 mg/l nitrite, you'd have to remove the fish to a bucket, change all the water, then reintroduce the fish. Alternatively, change 50% now, 50% after an hour, and 50% after another hour. This really is lethal. Meantime, do not feed the fish until ammonia and nitrite are 0. Seriously. No food. Even two weeks without food
won't harm them, but further exposure to non-zero ammonia and nitrite will.>
She also gave me a product to help with the levels
<Do understand no chemical will magically make water safe from ammonia and nitrite. There is really only one "bottle" you must use. This is water conditioner. In your situation, the only other product you might consider is a bottle of filter bacteria (such as Tetra SafeStart). These products are very hit-and-miss in terms of working. Sometimes they help, something they don't. But they're cheap and worth a shot in a crisis. Otherwise, the only way to eliminate ammonia and nitrite from your fish tank is a working filter. Find out why yours isn't working. Is the tank newly set up? Is the filter big enough for your tank/number of fish? Do you have the right media in the filter? (As a hint, carbon is useless while sponges and ceramic noodles are essential.) Is the flow rate normal or slow because the filter is clogged? Is there enough oxygen for the bacteria? Is the tank overstocked? Are the fish overfed? Is there a corpse somewhere rotting away? Various possibilities. Cheers, Neale.>

Re: URGENT MOLLY HELP...    12/8/14
Hi again. I figured out some of my mollies weird behavior. I put her in the
hospital tank as she was acting weird and this morning I found babies. She
was acting normal. I also did several large water changes yesterday and
changed my filter.
<Sounds like you're making progress. Good luck! Neale.>

Re: URGENT MOLLY HELP      12/8/14
I tested the water and the nitrite and nitrate levels are down now.
<Cool. Keep nitrite at zero, and nitrate as low as practical (below 20 mg/l ideally). Don't feed the fish if nitrite or ammonia aren't zero; do water changes instead.>
Thanks for your help.
<Most welcome. Neale.>
Re: URGENT MOLLY HELP      12/8/14

Hi Neale. A new problem emerged which has happened before. My balloon molly has done this before but it seems worse. She used to occasionally swim with her head facing down and she has been doing it all day and can't seem to right herself.
<Assuming she's otherwise healthy, constipation could be the problem here.
A common problem where deformed herbivorous fish are concerned. Read here:
Treatment involves Epsom salt and plant-based foods.>
She also hasn't eaten even when i put her in the hospital tank. I'm thinking its swim bladder disease but not sure how to treat it. (everything I'm reading says to feed her peas or have a vet x-ray her ((not going to happen)))
<There's no such thing as "Swim bladder disease" any more than a broken leg is a disease. It's a description of a set of symptoms including the inability to orient themselves properly. Constipation is the commonest cause. But Dropsy (associated with raised, "pine cone"-looking scales) and some bacterial infections (alongside disinterest in food, lethargy) can cause similar symptoms. Cheers, Neale.>

Poecilia velifera Parasite or Bac. Concern      8/30/14
Greetings Crew, I've recently purchased(2 weeks ago) a few Sailfin Mollies.
I have them in 40g breeder quarantine tank filtered by a small aquaponic grow bed(7 gal), homemade interior filter and air stone. One female has a large stomach with no gravid spotting and does have a very slight prolapse in rectum.
<Mmm; perhaps a bit of Epsom Salt>
This fish is mostly clear(in coloration) and I've noticed a black, some what blotchy pigment spreading under skin. It started behind gill plate, down toward stomach and slowly progressing backward. The fish seems healthy aside from conditions mentioned, feeding well, active, etc. No other fish are showing symptoms.
<What other fish/es (species) are present? The water is hard, alkaline... salt/s present?>
The other females have delivered fry except for this one. I'm considering treating for parasites and/or bacterial infect.
<Mmm; dangerous to just add medicines w/o knowing specifically what you're treating>
I have Metronidazole
<Toxic... just one dose. See WWM re>
on hand and was considering using it. I also have Furan and PraziPro. I do have access to Oxytetracycline, if need be. Which would you suggest, if any at all?
<Again; none w/o better knowledge of cause/etiology here>

My water supply is "hard"
<How hard?>
and I do add marine salt.
<Ah; good... IF your other life can/will tolerate it>
Do you think I could omit the salt without any negative consequences?
<Can't say w/o knowing more... the other life present mostly>
Thanks for the great site. Aloha Brandon
<Welcome. Bob Fenner>
Re: Poecilia velifera Parasite or Bac. Concern       8/31/14

Thanks for reply Bob. These fish are quarantining in a tank just containing 4 female and 2 males sailfin Mollies.
<Ahh, thank goodness>
Really haven't noticed aggression towards any fish. The fish in question seems to be the most dominant fish in tank. Soon to be added to a larger school of strictly Sailfins. My water hardness hovers around 75mg/liter, ph of 8.3.
<Ahh; about what ours is>
What would be the best way to ID an internal protozoan infestation on a living fish?
<Sampling... and microscopic examination. A bit of this is gone over... on WWM>
Thanks for the help. Have a great weekend. Aloha Brandon
<And you, BobF>

Poecilia velifera Head Standing/Whirling     6/14/14
Greetings WetWebMedia Crew,
I've recently purchased four sailfin molly (1male, 3female) labeled Poecilia velifera, mostly harlequin in color, farm raised in SE Asia, in hopes of adding some new blood to my school. Initially they were put in a
cycled 20g quarantine tank with about half strength sea water (tetra marine salt). With in a few days a gravid looking female started swimming head down a bit. I separated her into 10g fry tank(I use for smaller livebearers, a bit small for this fish) increased salinity to 3/4 sea water with marine/Epsom salt filtered only by over sized sponge filter and ample Java moss.
<75% seawater salinity and Java Moss growing? Doesn't sound likely. Do you have a hydrometer handy? A specific gravity of 1.003-1.005 is AMPLE for Mollies, and should be tolerated by the Moss well.>
I do keep nitrate below 5 in all tanks by water changes. After 48 hours she was head standing, bouncing off bottom and ornaments. What was interesting was she continued to graze on algae, as she was inverted. With in 24 hours she was head standing but whirling also. She does appear to have a slightly scabby look between eyes on topside. The other fish look to be lethargic also. I'm hoping its not whirling disease. These tanks run warm around 79F. What are your thoughts? Thanks as always for the great
site. Aloha Brandon
<It's possible they've reacted badly to something in transit and injured their swim bladders, or they're constipated, or indeed as you suggest, they may have a disease of some sort. Really hard to say. Shimmying and other sorts of odd swimming behaviours are common in livebearers when stressed or
exposed to poor conditions. Assuming your aquarium is well maintained, this may be one of those "wait and see" situations. If the fish is/are feeding, there's hope. Cheers, Neale.>
Re: Poecilia velifera Head Standing/Whirling

Thanks for the reply back Neale. As far as my Java Moss it was growing in pure fresh water, until about 48hrs ago, I then added the salt in hopes of combating possible parasites and/or bloat. I do have a couple hygrometers but didn't use in this case just measured salt. The Moss looks good at this point and I'll do a water change in couple days(or as needed). Thanks
<Glad to help. I just find it hard to believe you have ~26 gram salt per litre water, which is what 75% seawater would be. That salinity would surely kill Java Moss off in a few days. Review, and act accordingly. SG 1.003, which is about 5-6 gram/litre at 25 C, is more than enough to
optimise health for Mollies. Cheers, Neale.>
Re: Poecilia velifera Head Standing/Whirling     6/14/14

Sorry I meant hydrometer, not hygrometer(wrong hobby) in my earlier message. I don't dose all my tanks that heavy, but it is a 5g(fry tank). So didn't add up to much(marine/Epsom salt). I will check when I get home.
Thanks Brandon
<Real good. Neale.>
Re: Poecilia velifera Head Standing/Whirling     6/14/14

Another correction 10g fry tank, low blood sugar is getting to me.
<Ah, I see! Neale.>

injured molly       2/6/14
Yesterday one of our balloon belly mollies got stuck behind a plastic breeding tank I think she got a little bit squished she is pregnant and had something coming out of her rear end. By the time my husband found her she was barely breathing, I immediately placed her in a bowl of water from the tank i added in marine salt
<Do review the needs of Mollies, here:
The addition of marine salt on a regular basis is an excellent idea, if not completely essential. Using salt to medicate fish is not a silver bullet though, or even helpful on many occasions; see here:
Have a read before using salt randomly; can do more harm than good.>
and some hydrogen peroxide 3%
<Why???? Sounds a terrible idea to me. Hydrogen peroxide is a bleach, and having that on the poor fish's gills! Yikes!!!>
she started swimming around shortly after and her color started returning. I left her in there for about 20 min.s then put her back in her tank but she is obviously injured she sometimes can’t fight the current or goes nose down in the tank, she is having difficulty swimming. What else can I do for her so she can recover? Is she even going to recover?
<Do read about optimal conditions for Mollies; clearly these will be necessary for speedy recovery.>
our tank conditions are almost perfect, no ammonia or nitrites and good nitrates, we have live plants in the main tank.
<Hope this helps, Neale.>

Male molly seems 'lonely'     1/21/14
Hi crew,
I have a community tank with various fish but mainly mollies and platies.
Our largest female gave birth but died after a month. The male seemed to be pining for her, he kept low in the tank, started losing his colour and hid underneath the filter.
<Do read, here:
Almost certainly your "unhappy" Molly is responding to some other stress factor, perhaps environmental if water quality isn't spot-on (nitrate levels need to be below 20 mg/l in freshwater) or the water isn't hard enough (the harder the better, 15+ degrees dH hardness, pH 7.5-8.5).>
This morning he was just lying on the bottom of the tank and eventually died. Could this be a disease in our tank or does this happen with males that have mated with a female for a long time? (We have had them together for more than a year and they used to swim together all the time)
<Mollies do not need company, and form no bonds whatsoever with each other.
Male Mollies are aggressive towards one another, and will attempt to mate with any/all females that pass close to them.
They can be very persistent, and this can/does stress unreceptive (i.e., pregnant) females, potentially causing miscarriages and even the death of the female. Mollies are best kept in large groups with females outnumbering males by at least two to one; failing that, just keep virgin females.>
Thank you for your help,
<Most welcome, Neale.>

My Dalmatian Molly; sys., hlth.       1/1/14
I got a 36gallon tank for Christmas. I filled it with filtered water
<What do you mean by "filtered water"? Did you buy drinking water from a grocery store? Do you know the hardness and pH of this water? Do understand that tap water, if treated with water conditioner, is best for most tropical fish because it is inexpensive and you can afford to do large, frequent water changes (25% a week is a good target). While drinking water might sound a better idea, it's expensive, and "good" water that isn't changed very often won't help the fish in the long term. One last issue is water chemistry. Mollies (and Guppies, and indeed most other livebearers) need hard, alkaline water. If you keep them in soft water, they'll quickly sicken and die. If all else fails, add salt to the water. A good target here is 3-6 grams per litre (about 0.4-0.8 oz per US gallon, roughly 2-4 teaspoons per US gallon). Marine aquarium salt is ideal and inexpensive in the quantities required -- you'll find even a small box will last many months.>
and let it sit for 2-3 days with the filter and heater running and ever since it has remained at 76 degrees.
<Do understand that running the filter without fish in the tank does nothing to mature the aquarium. It's a good idea in the sense it shows you the aquarium is set up properly and isn't leaking, but other than that, it's pointless. The filter won't mature until you add fish. Unfortunately for you, Mollies are extremely bad fish for maturing new freshwater aquaria. Oddly enough they are very hardy in brackish and marine aquaria, and historically were often used to mature such tanks. But in plain freshwater tanks they very, very quickly sicken when exposed to non-zero ammonia and nitrite levels.>
Saturday I bought 3 fish. A blue guppy a yellow guppy and a Dalmatian lyre tail Molly. I don't want any babies so I got all males.
<Do understand these will fight. Mollies are not sociable, and males especially so.
Females are a better bet for a quiet aquarium, and even if they are pregnant, they'll eventually run out of babies and your tank will become a baby-free zone. Remove unwanted fry as necessary, and your local pet shop will probably take them. If you leave them in the tank, they're actually a good insurance policy for the future, bearing in mind not all your original fish might survive, and over the years, having younger fish to replace older ones is useful and economical.>
And they said add only 2-3 fish at a time.
<Yes. But Mollies are such bad fish for maturing tanks, even this won't guarantee success. Do note that adding salt as instructed above will turn the aquarium slightly brackish, dramatically increasing your odds of success (in brief, salt slightly detoxifies nitrite, and the hardness in marine aquarium mix further helps Mollies maintain better health.>
Well when I got them home I let the bag sit in the tank for a little bit before I put the fish in. Once I did so they seemed happy. Well a little while later I noticed the Molly was breathing really hard and I figured he was stressed.
<Correct observation. Did you do an ammonia or nitrite test? When you cycle an aquarium, first ammonia goes up and then comes down to zero within a couple weeks. A few days after the ammonia goes up, nitrite starts to go up as well. Eventually it comes down, usually within 3-4 weeks, by which time the aquarium is now cycled.>
He hasn't died yet but this morning I found my yellow guppy kept swimming to the top.
<Likewise, modern fancy Guppies are extremely sensitive delicate fish.>
He looked like he was trying to get some air then he would stop moving, turn upside down and sink to the bottom.
<Classic stress behaviour.>
He kept doing this and I noticed even when he was swimming back to the top his gills weren't moving they were just like sticking out. I took advantage that he kept swimming to the top and caught him in a bag. I let some water flow into the bag along with him and after about 15 minutes he wasn't "coming back to life" anymore and trying to get air. He was the calmest of them all and the most active I'm not sure what went wrong.
<Easy: you added sensitive fish to a non-cycled aquarium. While some fish are tough enough to go through this, with care on your part, Mollies and Guppies are not (at least, not in freshwater conditions).>
Now onto the story about the Molly... He really isn't social at all and sometimes his tail end (is that posterior end?) would be bent sideways and he would tread water like that for a minute or a couple minutes.
<This behaviour is called "Shimmying" and it's a neurological symptom often seen with Mollies and Guppies when stressed. It fixes itself if conditions improve.>
I don't know what to do
<Get a nitrite test kit (not a nitrate test kit, they're different). Do a test. If nitrite isn't zero, don't feed the fish, and do a 20-30% water changes (ideally, adding salt to each batch of new water as mentioned above). Regardless, do water changes every day for the first couple weeks.
Thereafter you might get away with changes every 2-3 days depending on the nitrite level. Expect all this hassle for the first 3-4 weeks until nitrite stays resolutely at zero for 2 or 3 days in succession. During this first 3-4 weeks from the time you add the first fish, feed extremely sparingly, a tiny amount (a 2-3 mm crumb per fish, say) and only every 2-3 days. Don't worry about fish starving. Isn't going to happen. Takes weeks! But ammonia and nitrite can kill fish within a day. Use your nitrite test kit regularly, every day or two.>
I don't know if something is wrong or what but I don't want it to die.
I don't notice him eating very much either.
<See above; not a problem. Will eat when conditions improve.>
I haven't had fish for several years but I thought I'd give it another shot. I'm extremely novice, I've never had more than a 5 gallon sponge bob square pants tank with a Betta in it until now.
<Hope this helps, Brooke. Do read:
Follow especially the links on that second article re: Molly disease; almost always caused by the environment, and what applies to Mollies largely applies to Guppies too. Cheers, Neale.>

Flashing molly. Env., using WWM      9/13/13
I have  a 2 month old  29 gallon tank cycled for 3 weeks  with CaribSea  media containing bacteria. (fish food  added  to  feed  bacteria). Added 4 neons,
<Stop: Mollies and Neons (tetras) are not compatible... water quality nor temperament wise.
See WWM re both, all species>
 after 2 weeks 3 lyre tail Dalmatian mollies, 4 more neons and 2 Corydoras.
Only learned now  the  need  for  brackish water for mollies which I can't address because  of  the  other  fish in the  tank.
<Ah yes>
My question is that I  see  the mollies flashing occasionally,
<Likely the water quality issue you've just mentioned.
Again, just search, read on WWM re their systems... NEED hard, alkaline, cooler, often salty water>
usually against plants especially the pregnant one. If  I  watch  for 30 minutes it  will  flash 1-2 times. I see  nothing  on  their bodies  that  looks like  Ich and  they  seem  active  and  happy, feeding, playing  grazing on plants. I started  treatment with Jungle Ich
<Stop again: The real issue here won't be solved by pouring in "medicines"... The environment has to be fixed>
 clear following  directions for 2  days  now. Still nothing  on  their  skin that I can see (they  are  mostly white) or  on the  other  fish.
Raised  temp to 80.  Still look active and  healthy to me. Is  this  flashing possibly  just normal behavior? I saw  the  Corydoras do it  2  times, never the neons.
<... Read on! Use the search tool, on every page on WWM. Bob Fenner>
Re: Flashing molly.     9/13/13

I am sorry , I should have mentioned that i have checked the  water quality couple of times these past  week. No nitrates or nitrite, chlorine, pH 7.2, total alkalinity 80 (moderate), hardness 75ppm.
<Good; and no ammonia I take it. BobF>
Re: Flashing molly.

The neons and mollies just ignore each other to my eye.
<... they'll soon be dead if not accommodated. READ where you've been referred. B>
Re: Flashing molly.
So this behavior is not "normal". It indicates something?
<Read, don't write. B>
Re: Flashing molly.

I have read and read for 1 week now. It is because of reading I started the medication. What should I read on WWM. Thank you for your help.
and the linked files above
Re: Flashing molly.     9/13/13

my test doesn't have ammonia

Molly problems, rdg., using WWM     2/4/13
Hi, I was wondering if you could try to help me. I had seven mollies, two males (one adult, the other was about 9 months old) two females, both adult and three fry. They were originally in a twenty litre tank.
<Much too small a volume for Mollienesia>
I bought a new 50 litre tank
<This too>

and I got the new tank up and running, placed some gravel into the filter from the old tank for the good bacteria, got the ph level to the same ad the old one and transferred them. I then set about taking the ph down to where it should be slowly so as not to put the fish into shock. It was at 7.6 and I took it down to 7.2 over a fortnight. My adult male was the first to die about a week after this. He started gasping by the top of the tank.
I noticed white growth near his gills and treated for fungus. When that didn't work I treated for gill flukes as I noticed blood near his gills and at the base of his body. Nothing worked and he died. Next month, one of the female mollies became very emaciated and couldn't swim properly. I assumed swim bladder
<... no such thing>
as she was head down and bobbing with a bent spine. I fed her peas but she still died. Today I noticed my other male (who is by now 1 year old) very skinny and not swimming. He kept getting caught in the filter and was too weak to swim away. I took a sample of water to the pet store and the test were fine. Ammonia, chlorine, nitrates all good. He gave me some good bacteria to put in the tank but wasn't able to help me with what was wrong.
My other female is doing ok, looking plump still and the babies seem to be doing great as well. I have no idea what's wrong and I'd really like to get some different fish to got in the tank but I can't while they are dying mysteriously. Thoughts? - Sinead
<... Please read here:
and the linked files above; esp. the Molly Disease FAQs files. Bob Fenner>

Black Molly keeps sinking     1/3/13
Hi, I know this may be redundant, but I have a female black molly who has been in the tank for two weeks.  The tank mates are 1 large female Dalmatian molly whom I've had for a year, three black skirt tetras and one lone Danio.  I am using the API test kit and it always reads zero, except a couple of times two months ago when the nitrates were red.  It is a 29 gallon tank and the LFS said it may be understocked and not cycling.
<Unlikely. After a couple of months, unless you were steam-cleaning the filter media or something like that, the biological filter should be adequately matured for the livestock you have. By definition, the filter becomes sufficient mature for the fish in your aquarium. Add more fish, and more bacteria will colonise the filter media because there's more for them to "eat". Remove some of the fish, and some of the bacteria will die back from "starvation".>
The black skirt tetra started off pooping giant red strings and then stopped.
<Do review Camallanus; it's a common nematode infection. The symptoms are obvious: red worms wriggling from the anus. Otherwise parasitic infections (like Hexamita, treated with Flagyl) can cause excess mucous to be produced, resulting in long, stringy faeces, and if you feed colour-enhancing (i.e., red) foods, then faeces will be red.>
It's tail started to droop down.  I was afraid of swim bladder but hoped it was just constipation as it had thin white strings hanging.  I fed it peas and for the last few days and it's tail fin was normal and it seems perfectly fine.  It always eats robustly.
This morning I woke up to find the Dalmatian molly "propping" the black molly up.  If I wasn't so worried, it would be truly comical.
The Dalmatian literally was hauling the black molly around, bent over so she could support the black molly's weight.  I haven't seen either molly poop after the initial round of peas and fed them peas last night.  I did a 30-40 percent water change and now the black molly's tail goes up, except when she is sinking down.  When she is near the ground, her tail is straight and looks normal.
Now I don't know if the black molly is constipated or is still having swim bladder issues.  I am not going to feed them anything for the next two days (I feel badly for the tetras and Danio) to see if that works.  I don't want to buy an antibiotic as I've tried that before for a deceased tetra who had PopEye and it did not get caught in time.  The water temperature is almost 82, and all the fish seem to adapt to the higher temps.  I'm trying to keep parasites from growing.
Any ideas?
Thank you!
Frustrated fish lover constantly on death watch…Victoria
<Do please read here:
Mollies are difficult to keep at the best of times, and have a notorious reputation for being disease-prone when kept in average freshwater aquaria.
As you've seen, you can have one specimen that seems fine for months, while another in the same tank is nothing but trouble, lurching from one disease to the next. Typically it's the environment that's the problem, but Fungus, Finrot and Camallanus worm infections are common too. Cheers, Neale.>
Re: Black Molly keeps sinking     1/3/13

Neale, thank you and I should have re-read what I wrote.
The black molly was the one with the red poop, the tetras are fine.  After the red stopped, the white started and when the first round of peas started, she had some color.   Now there is no poop at all.  Should I try another round of peas?
<If you want; won't do any harm. But do read those pages I linked in the last e-mail; Mollies are prone to Camallanus worms (especially in the US, it seems) and in freshwater tanks they are only variably healthy. If you can move them into at least slightly brackish water (2-3 gram/litre is ample) they do much more reliably better. As much as people would like to use Mollies as community tropical fish, they're not, and they really do need quite careful maintenance to do well in freshwater. Low nitrates and high hardness are crucial. By contrast, in brackish and saltwater tanks (yes, saltwater tanks) they are very robust.>
Also, I'm using a tetra whisper filter and the "bristle things" that are supposed to colonize the bacteria are filled with gunk that looks like stuff the charcoal should have stopped.
<Do remember to remove charcoal/carbon while medicating.>
Would that prevent bacteria from growing?
<No idea. Not sure what you're talking about; perhaps a photo of the "bristle things" would help. But in general terms, short of misuse of medication or careless over-cleaning of the filter media, biological filters are pretty hardy and difficult to damage.>
Thank you again so much.  I have been a fan of your site since I started this crazy hobby of fishkeeping.
<Thanks for the kind words. Cheers, Neale.>

Very distressed silvertail molly    11/7/12
Hello, I'm hoping that you can help me. My daughter has a silver tail molly that is very sick. She has a 10 gallon tank with 1 female black molly (very pregnant!), 1 older large female Dalmatian molly, and 1 male silver tail molly. The females seem fine; the male, however is very sick. About 3 days ago he started to experience spasm-like contortions in his body and he sort of floats with his head upward; like an underwater buoy. His pelvic fins (on the bottom?) are either closed up or chewed up or something. They look like they are missing pieces. He is able to swim horizontally, but sometimes he appears to be very exhausted. He seems to be gasping at times, but I'm not sure if I'm imagining this because I know something is not right. He is still eating some but he seems to need to rest a lot. For the most part he is staying away from the others. My daughter loves this fish and it is just gut wrenching to watch him and do nothing! (Sorry about the lack of correct terminology, we are just learning.)
<Hello Faith. Can you help me to help you by reading here first:
Most problems with Mollies are environmental -- wrong size tank, wrong water chemistry, wrong number of males to females, wrong number of Mollies for the size of tank being used. Look to see what you're doing different to my suggestions, and that's likely the problem here. The fact one Molly is sicker than others is not at all unusual; genetics works like that, with some specimens being weaker or more sensitive than others. Cheers, Neale.>
Re Sick Silvertail    11/8/12

I will take a look. Thank you so much for your help!
<Real good. Cheers, Neale.>

Orange Molly under observation tremors after eating     8/9/12
Hi all,
Thanks for this great site and the solution of the problems discussed here in detail. 5 months before when we started our new fish aquarium we ended up losing some 5-6 fishes but then came across this site. This site helped us a lot in maintaining and treating our aquarium. We learnt so much from this site that we were actually able to save our black lyre tail Molly from dropsy. That day it seemed that he is going to die as it was swimming heads-up vertically. Today he is perfectly fine and is the most notorious fish in our tank :).
Well, this time it's something new and we are not able to find a solution.
We have a orange male Molly and some 4 days ago we noticed that at times it is getting vertical under the flow of the filter water current. We also noticed that there is mix of white and red (color of the food ) color poop. Since the white color proportion was more and also he was getting vertical at times - we decided to treat him with Copper Safe and Maracyn 2. Today is its 5th day of the treatment. Meanwhile we fed him peas for two days along with the medication and then started giving him normal flakes. Till yesterday it seemed that things are going fine and that we will be able to put him back in the Aquarium soon. Yesterday -we noticed that as soon as we gave him flakes - it did finish it and then started scratching against the wall. At times it also shook its body as something is bothering him from inside. Since it was its 4th day medication, we were still calm but today again the same thing happened. We did give him less flakes compared to yesterday's amount , yet it behaved the same way. There are no other signs of any problem. He swims perfectly well and eats like anything.
Any suggestion as to what went wrong and then should we really continue putting him under medication. Since its going to be the 5th day - we are worried about him.
Note - he is already in a hospital tank and we are changing 50% of the water everyday and putting up fresh medication as per the mentioned dosage.
Thanks a lot in advance
<Hmm… do start by reading here:
And then have a peruse of this page, plus the subsequent Molly Disease FAQs:
There's something called "the Shimmies" that affects the way Mollies swim. It's said to be neurological, but caused by some shortcoming in the environment. Switching Mollies from a freshwater to a brackish water aquarium may (often does) make all the difference. If that happens with your Molly, then problem solved, and like some (though not all) Mollies, this chap will do better, stay healthier in brackish water. Start by raising the salinity in your hospital tank to 5 grammes marine aquarium salt mix per litre of water; that's about SG 1.003 if you happen to have a hydrometer. Of course brackish water won't be tolerated by most community fish, but since Mollies aren't community fish anyway, and best kept among their own kind, this rarely poses a problem to the serious fishkeeper. By testing the effect of salinity in a hospital tank though, you can see if this'll be the cure before changing the salinity in the main aquarium. Cheers, Neale.>
Re: Orange Molly under observation tremors after eating     8/9/12

Thanks for the prompt reply - we are already using API Aquarium Salt for the Freshwater Fish (again all thanks to WWM) .
<Can we please be clear here -- "aquarium salt" is NOT marine aquarium salt, and it is NOT AS GOOD as using marine aquarium salt! When you buy aquarium salt, what you're getting is overpriced cooking salt without the added iodine (basically, Kosher salt).>
We use 1 table spoon of this salt per 5 Gallons of water.
<Not enough to make this brackish. How to put this? SG 1.002 is 5 grammes/litre, 0.65 oz/US gallon. One US gallon is about 3.75 litres, so we're talking 3.75 x 5 grammes = 18.75 grammes per US gallon. With me so far? (Might want to check my maths!) There is roughly 6 grammes of salt per level teaspoon (check your own spoons using kitchen scales), and 3 teaspoons per level tablespoon, so 18.75 grammes is roughly 3 tablespoons of salt PER US GALLON. In other words, you're dosing one-third as much as would make a difference.>
We have a 20 gallon tank.
<Too small for Mollies. Besides the fact they are big, active fish, the males are aggressive bullies.>
We have put some 1/4 tablespoon of salt in the Hospital Tank too which is a 2 Gallon box/tank.
<Not a long term solution… unlikely to live more than a few days in a tank this tiny.>
Now, should we use Marine Aquarium salt in place of Freshwater Fish salt
<For now, don't worry; use the freshwater salt you have, but up the dosage as described above.>
or should we increase the salt amount in the Hospital tank? We don't have a hydrometer with us.
<Do see above for how to produce useful concentrations.>
And should we continue putting him in Hospital tank ?Is that OK ?
<I would make the main aquarium more salty. You have just Mollies in there?>
<Cheers, Neale.>

unhappy molly    8/2/12
Hi there, I have a few molly fish in my tank but one has been causing some concern. She is a female and has never given birth, however she is very fat, she isn’t a balloon molly. She just seems to get bigger, I do have 1 male in the tank and he has mated her, but she doesn’t have a gravid spot and like I say has never had fry. She does hide most of the day, but in evening swims about fine. Could she have unfertilized eggs in her? She always seems to look swollen and sometimes open a little, but has been that way for several months. She isn’t constipated either. Any advice is most welcoming. Thank you. Michelle
<Do need some more information than what you've given here. How big is the aquarium? How many Mollies (and other fish) in there? What is the water chemistry? Do you add marine aquarium salt mix or aquarium salt or neither? What's the water quality (nitrite at minimum, and ammonia and nitrate levels are useful too)? In the meantime, have a read here:
Most problems with Mollies are environmental, so it's important you check these factors first. Cheers, Neale.>|
Re: unhappy molly    8/2/12

Hi that's for your response.
I have a 30 gallon tank, with 2 female Molly babies 1 adult male plus the adult female.
<Ah now, do recall the need for (at least) twice as many females than males.>
3 male guppies, 3 Platies and 1 platy baby and 3 Corydoras.
<Corydoras don't really belong with Mollies; if you're adding enough salt to help the Mollies, you'll be stressing the Corydoras.>
GH was 60, kH 80,
<Much too soft.>

ph 7.0, NO2 0, NO3 0. I add aquarium salt.
<Clearly not enough. In soft water -- which you have -- use marine aquarium salt (not "aquarium salt" or "tonic salt") at a dose of around 5-6 grammes per litre of water. Alternatively, if you plan to keep the Corydoras, you need to harden the water considerably. Read here,
and use the Rift Valley salt mix at about one-half the dose stated there for Rift Valley cichlids.>
I do 30% water change weekly.
<Sounds good. But the Molly likely has Dropsy or some other stress-related problem. Read where you've been sent, and the relevant linked pages, and act accordingly. Cheers, Neale.>
Re: unhappy molly    8/4/12

Thanks for quick response. I have treated for dropsy anti internal bacteria after 1 of my coras swelled up and unfortunately died.
<So-called "Anti-Internal Bacteria" medicines sold in the UK are almost always useless. Unfortunately for the aquarist, you really do need a combination of exceptionally good care together with antibiotics to effect a cure; in the UK, that means a trip to the vet.>
The Molly has been this size for many months and doesn't look swollen like the Cora did, she does often scrape her belly on bottom and side of tank though. Also to change to marine salt do I need to change water completely or just switch gradually with each water change?
<Are you keeping the Corydoras? You can't add marine aquarium salt to the tank if you're keeping Corydoras. Let me try to keep things simple here.
Soft water is water with a low hardness -- i.e., few dissolved minerals. In the UK that tends to be the sort of water you get in places like the Scottish Highlands and the West Country. Adding plain "tonic" salt to the water doesn't harden it as such, but if you use enough, it can offset the problem enough for Mollies and Guppies to thrive. But adding tonic salt, and even more so adding marine aquarium salt (which is better because it *does* harden the water) will stress your Corydoras. If you must keep Corydoras with Mollies, read the article about water chemistry, review what you need to make Rift Valley salt mix (it's super-cheap: Epsom salt, baking soda and marine aquarium salt mix) and works very well. In the short term, you could substitute the marine aquarium salt mix with the tonic salt you have. Literally, pennies per water change. The Epsom salt raises the general hardness (which needs to be about 15 degrees dH) andy the baking soda raises the general hardness (which needs to be about 5 degrees KH) so together these raise the mineral content of the water. The recipe is per 20 litres I think; half the amounts for what you're trying to do, and it should work just fine.>
Thanks again
<Cheers, Neale.>

Does my molly have Ich?    7/21/12
I bought this molly a couple of days back. It's being housed in a 10 gallon tank.
<Much too small.>

I noticed that it's not all black. There is this patch which shines gold when a light is shone onto it. Is this natural coloration or does it look like Ich? The nitrate and ammonia levels are normal and the temperature is around 30 degrees.
<I believe this is normal, metallic colouration seen on some varieties.
Seems to be the actual scales are iridescent, rather than silvery specks.
Meantime, do read:
Cheers, Neale.>

Pregnant Dalmatian Molly will not settle down! Troubles from too-small worlds    6/28/12
Hello, it is me again. This time I have a new problem. I bought a pair of Dalmatian mollies at PetSmart yesterday. I didn't discover until I got home with them that at some point, the ten gallon tank I was going to put all my "kids" except Grace, (the pregnant one) into.
<Mollies need more room than this... for a few reasons. Do read here:
and the linked files above>
 So, instead of putting all of them in the ten gallon, (except Grace), I wound up having to put all of them in the Rubbermaid container I've used for when I clean tanks since I got my platys. Grace went into the fishbowl until I could get the smaller tank cleaned out. She seemed to get very depressed all by herself, (very lethargic, barely moved), so I put Black Sam, the other molly, in. This seemed to make her happier. So I cleaned my small tank, (I think its a five gallon), and put the mollies in it, along with a fake grass mat in case Grace went into labor. The rest of my aquatic kids had to stay in the Rubbermaid, (also about five gallon). They didn't seem all that thrilled, so this morning, I moved the three platys in with the mollies to try and even things out. I also ordered a new ten gallon tank.
<... too small>

 Everything seemed fine when I came home early from classes to check on everyone and try and work out an arrangement that suited everyone. Put my two loaches in their own container with their cave and most of the fake plastic plants from their tank and an algae wafer. Put the ADFs in the Rubbermaid with the modified lid to let air and light in and keep then in as well.
Mollies and platys were getting along, so I left them where they were. I also fed them lunch. Shortly after feeding, I noticed all of them "racing" around the top of the tank. I looked up this behavior and found that it was possibly caused by an ammonia spike.
<Maybe... and/or low DO, high CO2>
 I started doing partial water changes, and they would work for a bit, then they would start the "race" again. I have since done eight partial water changes, removed the male molly and the male platy to the fish bowl, (male Molly is still any, but not in the same way),
leaving only the females in the tank with Grace. I fed them a very light dinner, which the female platys ate some, but Grace wanted nothing to do with, and Grace isn't skimming the top quite as much, but she's still very any. Oh, and I have added aquarium salt, (very small amounts) to about four of the jugs of water I've used for water changes to try and ease her obvious stress. I'm going to do one more gravel vac and partial water change, and as much as I hope Grace will calm, I don't think she will. I'd put her in the bowl with the male Molly, but for one, the grass mat won't fit, and for two, he was chasing her around a lot when all the fish were in the five gallon. So was my male platy. My female platys seem content to do their own thing. But Grace just will not calm down! Please help. Thanks.
<... So... what you/they really need is a larger (20 plus gallons) stable, biologically-filtered system. Bob Fenner>
Re: Pregnant Dalmatian Molly will not settle down!    6/29/12

Hello, Bob. I went back to PetSmart today and picked up hose for my bubbler. This seems to have made Grace a bit happier, (also got Stress Coat+ and Stress Zyme+ for her) and split the air hose between the five gallon and the fishbowl the boys are in. I was hoping this would help with the O2 issue.
<Should... but not the accumulation of toxic metabolites>

 Now my male in the bowl is going nuts... Seems he doesn't want bubbles... But as to the 20 gallon tank, I can't afford one at this time. Perhaps next month, since I get paid monthly.
<I might return the new/er fishes till then>

 Most of the "housing" situations I have now are temporary, since my old ten gallon died. I'll certainly look into a bigger tank when I have the money though! I don't want my kids unhappy! Thanks.
<Certainly welcome. BobF>

sick orange molly?   6/20/12
I have an orange molly that has become a drab orange and has developed a large scaly swelling behind its head. It seems to be active and is eating, but the swelling is getting larger, appears very rough, and has become a light brownish color. Any ideas what this might be? Other mollies in the tank appear healthy with good color.
<Hello Deborah. Do have a read of this article:
Then click on the links at the top to the pages on Molly health and disease. Mollies are sensitive fish, some would say disease-prone, but most problems come down to environmental shortcomings. They're very particular about water chemistry and water quality, and throwing them into busy, mixed fish communities rarely ends well. Cheers, Neale.>

Betta? Or Platy? Identification Help Needed on Sick Fish    6/18/12
I managed to stumble across your site while searching for info on platys.
I was researching platys because someone had suggested that the new fish I bought might be on. Or a swordtail.
<Mmm, appears to be a Mollienesia species to me>
 I originally got it from Meijer's on Monday (went in for Neosporin, came out with a fish), and thought it was a female Betta. She seemed to have Ich
<Does appear so>

 and was in a community tank so I bought the poor thing and decided to see if I could fix her up. She had (has) clamped fins, along with (what I'm fairly certain is) Ich. I thought she was just an ugly Betta, but I noticed that she has an attached dorsal fin (she unclamped it a few days ago) that's longer than her single ventral fin (found that a couple of days ago too), and instead of two long/narrow ventral fins between the gills like a Betta, she's got a pair of rounded fins in front of the single ventral fin (just found them yesterday). Her lateral fins are narrow, and her body attaching to her tail is rather long and thin. Her tail (when she opens it), doesn't seem quite as rounded as a normal female Betta's. Her eyes seem larger than a normal Betta's, and her mouth seems to open up wider and can go into an "O" shape that I've never really seen on a Betta before.
She's black and her fins are clear, and she's been sitting in medicated water so I could barely see her, let alone photograph her. I decided to toss her into a small Betta cup to at least get some photos for identification from my Betta forum, so they aren't the best photos but you ought to be able to get a decent view of her overall shape and fin structure.
I'd love it if you have any suggestions as to what kind of fish she is.
I'm not really a fish person, so specific care info on that particular species would be great. (I got a Betta to be buddies with my ACFrog and it just kind of expanded from there).
Here's the link to the photos:
I'll attach a couple of the best photos too, so you can get the larger view.
I'd appreciate any suggestions that you have.
Thank you!
<Mmm, Mollies need cooler temp., hard, alkaline and brackish water generally... may not be environmentally compatible w/ your frog and Betta.
Please read here: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
and the linked files above... Do write back if it's not clear to you the paths to keep and treat this fish. Cheers, Bob Fenner>

Re: Betta? Or Platy? Identification Help Needed on Sick Fish    6/18/12
Thank you so much for the quick response.
Ok, so just to be clear, my fish is definitely not a Betta, correct?
It's not a platy, and is almost certainly some type of molly?

Any particular attribute that makes you think it's a molly?
<Overall physiognymy>
 (I forgot to mention that the fish beats its lateral fins alternately, not simultaneously when it swims, like my Bettas do).
Salt/pH isn't an issue: we have well water so the pH is usually 7.5, which stinks for the frogs/Bettas, but should be great for a molly. I usually add aquarium salt to my tanks anyway. I'm not sure how tolerant my Bettas (and lonely feeder guppy) are of salt, but so far they're doing fine with the salt I add to their tanks currently. I'll look that up today...
Any idea on what particular type my molly is?
<Mmm, not really, no>
I know most are hybrids, though. (And also is it a female?
And any idea on what size it will get to?
<Likely 2-2.5 inches overall>
It's normal Betta size right now).
Do you think there will be a problem with my Bettas eating veggies intended for the molly?
<No problem>
I know greens act as fiber for the Bettas.
I know now that mollies need large tanks. My Betta tank is about 10gal (2 calm female Bettas and a teeny feeder guppy I couldn't bring myself to feed to my frogs). I figure I'll start her off in there and see how it goes.
The frog tank is a 20gal, but they're big enough to eat her now.
<Ah yes. Xenopus are voracious piscivores>
 Depending on how fast she grows, I could always throw her in there with them.
<Mmm, no, not likely prudent>
 They mostly hang out around the bottom of the tank. (Both tanks are long sizes).
I'm really not prepared for a fish that requires that much space. I thought I was buying an injured Betta, not an awkward molly.
Just a few questions on transferring: I figure I'll keep the fish alone until a few days after she appears healthy. But how do I transfer the fish into her new tank? Won't the bacteria/parasites still be floating in the water?
<Mmm, possibly>
 I don't want to ruin my healthy tanks.
Thank you so much for your help! It's so difficult to find someone who can answer all the questions I have correctly (lol, I don't even bother asking most of the people in pet stores), and who is also willing to do so. :)
<Mmm, cheers. BobF>

Creamsicle Lyretail Molly Trouble and a salt question. Livestock of differing water quality needs tog.     6/13/12
Hello!  Thank you for such an informative site.  I have spent hours and hours reading the wealth of knowledge it provides...yet I still feel unsure about my situation.  I apologize in advance for possible info-overload, but I'd rather err on the side of too much than not enough.  My FIL gifted my 2 year-old daughter a 20 gallon aquarium for her birthday (at my suggestion; I was excited about it also, as well as willing to put forth the effort it requires).  At the time, my idea of keeping fish included water, a bowl, and some fish...little did I know!  Since then, 3 months ago, we have acquired: 3 Neon Tetras (unsure of sex),
<Mmm, these really need different water quality than the livebearers you're keeping... soft/er, more tropical...>

1 male Albino Bushy Nose Pleco, 1 male Lemon Cobra Guppy, 3 male Harlequin Sailfin Mollies, 1 female Creamsicle Lyretail Molly, 1 female Dalmatian Lyretail Molly, 1 male Mickey Mouse Platy, 1 male Sunburst Wagtail Platy, 1 female Red Platy (just died), 2 African Dwarf Frogs, and a single Ghost Shrimp who has survived this
whole time, amazingly enough!  I also have two varieties of live plants: Hygrophila and Cyperus;
<Cyperus? A sedge? Is this emersed?>
both have done really well.  Just this week, I began half-dosing the tank with Aqueon Plant Food (10mL/20 g).  In the beginning we lost a black Platy, and I didn't think twice about it at the time; I thought that fish just died...ce la vie.  I don't remember it having any spots/fungus/weird behavior indicating any of the issues listed on the Disease Troubleshooting page; however, I also did not know that it is best to quarantine new fish. 
We introduced 3 batches of fish within one week of getting the tank set up. 
<Uncycled risks...>

Fast forward to present.  This past weekend we were out of town for two days to come back and discover a tiny red female platy...obviously, the Red Platy had had babies, and we didn't even know she was pregnant.  Having the three females in there was a mistake; we wanted to only have males (is this even a good idea?).
<Can be>
 The reason being, I did not want to have to deal with off-loading baby fish...repeatedly.  Plus, I'm kind of half and half on how I feel about just letting the females have babies and it being a free for all for snack time.  *bag over head*  ...not sure how the experts feel on this?
<A mix as well>
 Yesterday, the female Red Platy died.  She had been sitting on the bottom of the tank, and I read and read and researched and couldn't come to a conclusion as to why she was doing this.  I ran out immediately and got a water test kit (yep, learned that I needed one of those 3 months too late). 
Today I tested the water before and after the cleaning/gravel suction; I replace 25% of the water once a week.
 I add 10mL of Aqueon Water Conditioner each time I do this.  These were my
readings after I changed the water: GH 30, KH 120-180, pH 7.5-8.0, NO2 0, NO3 20. 
<Keep Nitrate no higher>
The temp is always about 78 degrees F; today was the same.  I don't keep a fish heater in the tank, as we live in Arizona and I keep the house pretty warm...free heat!  These readings weren't much different from the before reading...the only difference being the NO3, which was 40 before the cleaning. 
<Too high>
According to the test directions, my GH is too high.
<Mmm, I wouldn't likely "fool with it/this">
  I didn't see the recommended solution
<Blending in some water (RO likely) w/ less mineral content>
 to that at my local pet store, however (API Electro-Right).  Also, is the pH okay, or does it need to come down a bit?  It seems fine for some of the fish, and too high for the others.
<Is high for the Neons, but not for all else>
I have since learned from all my reading that I have overstocked, and that I have mixed Mollies with other types of fish, when they should be by themselves.  I also have learned that by not having enough females to males, I was creating problems with chasing them to death; I'm still not sure why the female Red Platy died.  All of the fish chase each other in there; they always have (the guppy, especially, likes to chase the big Lyretails).  I never see them nipping, though.  I do not plan on restocking as fish die, and I hope to create a happy, safe environment for the ones I have...as best I can.  I have also learned that the frogs prefer to be alone, but these actually don't bother each other (seemingly).
 <Ah yes>
The problem I'm having with the female Creamsicle Lyretail Molly is that she has started floating upright, midtank, in the water.  She looks, occasionally, like she is shivering.
<The metabolite concentration... as "windowed" by your NO3 testing/results... poisoned by their own wastes. Very common>

 I have noticed that on her pectoral and caudal fins, which are fairly transparent, she has these whitish looking spots.  They are fairly bigger than grains of salt, leading me to believe it's not Ick,
<Maybe... though could "just be body mucus clumps"... reaction to water quality issue/s>
 and they aren't in clusters...just a handful all together.  She seems to swim fine when she isn't doing the vertical-hover-shiver thing, and she eats normally.  I noticed this morning that she has some bumps on her head...also fairly bigger than grains of salt.  There's nothing on her body that looks different or "wrong"...no white specs or anything.  I went to the store today with the knowledge from this site and hoped to have the "fish specialist" at my local pet store help me, but that turned out to be a fail.  I did end up spending a good hour perusing the medicines, and ended up coming home with Tetra Lifeguard All-In-One Treatment, but I'm unsure if it what I should put in my tank...?  
<I wouldn't>
Any ideas on what could be bothering her?
<The environment
... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
and the linked files above if still unclear>
  I just worry (now that I know better) about something infiltrating the whole tank and hurting more fish. I know (now) that mollies do much better in a brackish environment.
<Ah yes>
  My other question about that is, can I introduce marine salt, considering the other cohabitants and plants? 
<... Mmm, best for you to spend the time "looking up" such information... the Neons "don't like" salts... neither Hymenochirus... the livebearers are fine w/ a modicum...>
If so, do I introduce it slowly, or just go all-in and follow the directions on the box of API Aquarium Salt...which says 1 rounded tablespoon per 5 gallons of water (so 4 rounded tablespoons)?
<... you'll need to investigate, likely move the non-salt livestock elsewhere ahead of the addition>
Because I do have an overstocked tank, would more hiding places be encouraged?
<Mmm, yes>
 Currently, I have a piece of driftwood (fake) that takes up the length and height of the tank (but is narrow) to provide some good shelter, as well as the two types of plants I have now (the Cyperus, of which, has set out about a dozen runners that have sprouted up quite nicely, so I bunched them all in the same corner) and a small pirate ship (at my daughter's request...*smile*).  My idea was to add some plants to grow on the surface of the tank; would this be good?
<Yes; a/my fave Ceratopteris...>
 If so, what kind would you recommend based on my current tank environment?
I do thank you for your time. 
<You have two great requisite traits for being successful (not just w/ pet fish); a curious mind and desire to improve situations... Read a bit and do write back if you are unsure of a plan... to separate (have two systems) and modify water quality to suit the life in your charge. Bob Fenner>

Pregnant Molly   4/25/12
Hi, my name is Alejandro.
<Hello, Alejandro!>
On March 2nd I sent you a mail about a black molly fish which I bought and I thought was (or is) pregnant because she was having some territorial issues and I could notice that she was larger than the other female mollies. The thing is that today is April 24th and the molly just keeps getting bigger and bigger.
<I can see from the photos. But please, don't send 10 MB of photos next time! Resize them down to 500 KB each!>
I think that by now she should had given birth.
Now I'm not completely sure if she is pregnant
<If she is with a male, or has been in the last 6 months, YES, she is pregnant. But she may be getting bigger for another reason as well.>
or if she could be having some sort of problem. I have her with some tetras and another female molly but no male mollies.
<Tetras and Mollies don't mix. Mollies need hard, alkaline water -- preferably slightly brackish. Such water is wrong for tetras. Bloating and dropsy (oedema) are common when Mollies are kept in the wrong water, especially soft water. On top of this, she has a deformed spine (like the "balloon molly") which makes her look an odd shape.>
I attached a couple of pictures of the molly. Please tell me if she could be pregnant or sick. Thank you.
<Do read:
Cheers, Neale.>


Molly tail down...      4/23/12
WWM, I need help. I have some sick female Silver Lyre-tail Mollies (found a female one 'crashed' at bottom of tank this morning). I suspect the other 2 will not be far behind. Molly #1 has been hiding, shaking and shimmying since she had babies about a month ago. Since she never comes out of hiding I have only recently noticed her tail is drooping down (like her rear-end is paralyzed), there is a curve or kink in her spine so that tail is curled to side and fins are clamped. Also her eyes look 'fluorescent' blue with same coloring on top of body. Molly # 2 has had buoyancy issues for about 2-3 days with keeping her tail down and head up, today this seems better but she is swollen, clamped fins.
Molly #3 died with a swollen stomach, all 3 have(had) high-arched back (hump?) and low appetite. Gave all 3 a salt dip in similar water parameters of 1 gallon + 1 tbsp of Epsom salt for 5 minutes and placed back in tank yesterday. Today gave an additional dip to the 2 remaining only for 10 minutes. Have seen them scratch a couple of times here or there, but not constantly or even every day. Parasites? TB? Fungus? Lack of electrolytes?
<Likely the last... plus exposure to metabolites... Most common causes of Molly demise>

 Help :(  Also, in my 'baby' tank (20 g tank dedicated to the Fry of all the parent fish) the white mollies swim vertically (head up). They CAN swim normally, but at times they don't; they move forward (like belly forward) just straight up and down as if they were constantly swimming against a glass wall. What is this???
<The same>
Details of our tank: 30 g with 11 total of guppies (2 females, 1 male), platies (2 males-1 that can't breed, long story, 3 females) and 3 mollies (2 females, 1 male). Also have about a dozen (can't keep track) babies that have stayed hidden and recently came out because they seem to be too big to be eaten (parents don't chase them or anything) they could be anywhere from a week-2 weeks old so I don't see the need to move them now. We do 30% weekly water changes and keep a 78-79 degree temp and ph of about 7.6. Don't know the rest of the parameters but get it tested at the LFS and we are told it is 'fine.'
<Of no use... need to know specifics... esp. nitrogenous/Nitrate accumulation>

Keep aquarium salt (or canning salt when we are out of the other)
<Sea salt (marine) is what you want>

 at rate of 1 tbsp per 10  gallons. Also, recently learned about adding baking soda (yesterday) and added 3 tbsp of baking soda diluted in tank water over about 30 minutes.  I know that Mollies are harder than guppies and platies to keep but is this a species problem or something else going on?
<Most all mollies kept in captivity nowayears have troubles... really need to be kept in large brackish to marine settings>

Do I need to set up a 3rd tank and keep my mollies in their own tank from now on?
Sorry, I am not able to send pics (they are not clear) or video (Silverlight is dumb).
<Please read here: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
and the linked Molly Disease FAQs files above... all will be revealed. Bob Fenner>
Re: Molly tail down    4/28/14

Thank you so much for your quick and reliable responses to all of my questions! I am really not sure if my 2 female Mollies are on the mend or not. We are taking everything 1 day at a time. However, the 20 gallon tank, that I mentioned in my previous email that houses several batches of fry, is giving me cause for concern. The latest batch of fry that we added are 10 day old guppies. Several of them seem to have 'bent' tails and 1 of them has an extremely bent tail and is swimming around in circles,
<Bad... might be congenitally (genetically) troubled... could be due to nutritional deficiency, even some aspects of water quality>

being carried wherever the water takes it. It will then rest on the bottom a minute and then start again. Also, this fry has a very black tail, back, and head with a silver belly which is very different from the other fry and parents. Is this whirling disease?
 I've read about it on your sight <site> but wasn't sure if fry this young could get this disease.
Details of the tank: 20 gallons with a mixture of probably 50 fry: guppies, Platies, mollies. Ages range from 10 days old to about 3 weeks. We do about a 20% weekly water change and keep a 78-79 degree temp and ph of about 7.6.
Don't know the rest of the parameters but get it tested at the LFS and we are told it is 'fine.'
<Past time to have/use your own test kits>
We are still working on getting the proper testing strips.
<See WWM re... inferior technology>
 Keep aquarium salt  (or canning salt when we are out of the other, and we are also working on getting Marine salt as well as looking into Kent Iodine) at rate of 1 tbsp per 5 gallons (not 10). Also, added baking soda at rate of 1 tbsp per 10 gallons.
Thanks for all advise! -Amelia
<Not advice; just what I/we might do given similar and supposed circumstances. Bob Fenner> 

mollie with slime disease? No searching, reading... as too usual    - 4/18/12
Hi there, I was wondering if you could help me please. I have a black mollie that appears to be sick.
 From what is have read around, I think it may be some sort of slime disease, but I am not sure. I've added a picture to try and show you. At his sides, about half way down, his scales seem to have turned a greyish colour. He has also started to move his whole body side to side yet stays on the spot, and rub himself against the gravel. The tank is 180 litres and has about 40 small fish such as neons,
<A clue...>

minnows, rasoboras, 1 bristlenose plec and a couple of apple snails. It has been set up and running for about 5 months. I've cleaned the tank as i thought it may have been water quality, ammonia is 0, nitrite 0, ph 7.8, nitrate i think is under 40 but the api test is difficult to tell the difference between 40 and 80.
<Way too high>

 I've thought about adding salt but im not sure how suitable this is for the other fish and snails.
<The Neons, snails, no; not compatible>
should I try something like anti slime and velvet medication?
<Of no use w/o improving the environment.>

 Thanks, Carrie
<Read here: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
and the linked files above. Bob Fenner>

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