Molly Behavior/disease  1/4/09
Hello,
I have a 55 gallon freshwater community tank. I have some tetras, livebearers, and small catfish. I specifically have 4 small black mollies (still babies), 4 silver mollies, and 1 starburst molly. My water is perfectly fine. My male silver molly has been acting strange. He hides in every corner he can find, and when not hiding, he is swimming behind
plants, head up. He never eats the food, and just hides. He acts sick, but there is nothing on his skin. 3 of my 4 black mollies are in a quarantine tank for lip fungus. Help!
<Hello Rachel. One problem with Mollies is that they are not reliable freshwater fish. Most aquarists experience what you do when they are kept in freshwater tanks: lethargy, loss of colour, odd swimming behaviour, and random diseases including Finrot and fungus. The only 100% reliable way to maintain Mollies is to treat them as brackish water fish. Buy some marine salt mix -- not "aquarium salt" or "tonic salt" -- and add the marine salt mix to each bucket of water at a dose of around 5-6 grammes per litre. Marine salt mix contains carbonate salts that raise the hardness and sodium chloride that raises salinity. Together these things stabilise the pH and reduce the toxicity of nitrate, and it appears to be these things that help. (Tonic/aquarium salt only contains sodium chloride, and so doesn't do both these things, and is consequently a waste of money.) Mollies thrive in brackish water, and at low salinities so will other livebearers including Guppies, Platies and Swordtails. But do understand that most catfish and tetras do not appreciate brackish conditions, and consequently shouldn't be kept with Mollies. It's a very common mistake for people to buy Mollies for community tanks -- despite the fact most aquarium books state clearly Mollies prefer slightly saline conditions. Do read here for more:
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
Cheers, Neale.>  
Thanks!
<Most welcome. Neale.>

White Feces ~ 01/01/09 Hello, <Hello again!> About a year ago I emailed you about my sick mollies, since then I moved them into a brackish tank, and they have been perfect! <That's the idea!> I even added two more females and was surprised to find baby mollies a few days later. The babies are all grown now and everything has been great, until today. I noticed today that my adult balloon molly, Flo, had white stringy fecal matter hanging from her bum, that has not dropped, its been there for more than an hour. <There are really three things that can be relevant here. If there are red worms appearing from the anus (usually obvious because they move) then the Molly is infected with Camallanus and will need to be treated with an anti-worm medication. http://www.wetwebmedia.com/FWSubWebIndex/nematodesfwf.htm If the faeces contain much mucous, so that they appear pale, often semi transparent, then your fish might have a Hexamita infection, and will be needed to be treated with an anti-Hexamita (Hole-in-the-Head) medication. Hexamita is commonly associated with lethargy and general lack of condition (pale colours, weak swimming, etc.). http://www.wetwebmedia.com/metranidazole.htm Finally, there's plain vanilla constipation: very common where herbivorous fish such as Mollies are concerned. In this case the faeces will be coloured, often brownish or off-white, but solid rather than semi transparent, and dry looking rather than mucous covered. Mollies need to eat mostly green foods, and in the aquarium things like thinly sliced cucumber and sushi Nori sheet work great alongside a balanced algae flake or algae wafer staple food. Daphnia and brine shrimp are good aids to constipation, as is adding small amounts of Epsom salt. Although the article linked here is written for Mollies, it applies 100% for Mollies. http://www.wetwebmedia.com/FWsubwebindex/gldfshmalnut.htm > I have never seen this before, and after reading a bit online, I am very concerned that she has parasites. <By all means try a systemic anti parasite infection that treats worms and Protozoans, as they're the two likely causes of troubles in the digestive tract.> I am very attached to Flo, she is my first fish. What should I do? Should I wait to do anything? How do I treat her, and not kill the babies? <Medications safe for Flo should be fine with her babies.> The mollies are in a 16 gallon brackish system, currently there are 14 mollies in the tank, 5 of which are babies. I just did a 25% water change today, and all levels are normal. Please Help! Thanks, Lauren <Hope this helps, Neale.>

Sick Balloon Molly   11/25/08
Hi there, I wrote to you a little while ago and I think you probably saved my fishes, I'm just hoping you're able to do the same again!
I have a 90L tank with 2 female mollies, 5 guppies, and about 20 Molly fry.
About 2 weeks back I noticed that my Dalmatian balloon molly was acting a little subdued, hiding and not swimming about much. I checked the levels and the nitrites were high, I sorted those out and she seemed to go back to normal. I've recently noticed all of the fish (including the fry) scraping themselves on everything solid in the tank, but none had any outward signs of parasites. I went out and bought Sterazin Gill and Body Flukes treatment, and have been using the recommended dose. After 2 doses, I have come home to find my Dalmatian molly, pointing downwards, trapped between a plant and the wall. I thought she was dead but noticed she was still breathing. After bringing a net close to her, she swum off but has looked very ill since. Her stability seems severely affected, she's floating all over the place, just moving with the flow of the water, seemingly unable to control her movements, and bashing into things. She's often completely vertical, either pointing either up or down. Occasionally she'll come to rest in a plant upside down, and stay there motionless until I get scared and make her move. What's wrong with her? Do you think that I can save her? And should I stop the fluke treatment? Thanks for you help
<Sterazin is a medication that has been around for years. It is generally well regarded, and I'd be surprised if it was causing ill health, assuming it was used correctly. Do check you dosed the tank correctly: all medications are poisons, and the "art" is using them in the right amounts.
When measuring out the dose, it's important not to overdose. It's also a good idea to increase aeration when treating, because sometimes these medications cause the amount of oxygen in the water to drop. Also you have to remember to remove carbon from the filter; if you don't, the medication gets sucked up by the filter without doing its job. In any case, the thing with Mollies is that it is extremely difficult to separate actual diseases from the fact they almost never do well in plain freshwater conditions. I'd insist they be kept in brackish water conditions, at least SG 1.003 (about 6 grammes marine salt mix per litre). It's remarkable how many sick Mollies pep up when kept in brackish water conditions. The "treading water" behaviour often seen with Mollies is called the Shimmies, and is particularly common in tanks where Mollies are kept in freshwater. And no, adding a teaspoon of tonic salt per gallon doesn't make an aquarium brackish! Besides salinity, nitrate is highly toxic to Mollies, as are rapid pH changes, so these are two factors to review. Since Mollies and Guppies both do extremely well in brackish water, adding marine salt mix is the cheap and easy way to keep them in good health. Cheers, Neale.>

Re: black mollies   11/25/08
hi its me again so i went looking for marine salt and cant find it can i use the aquarium salt and i have also bought ick remover i put some in do i do my water change every day for two weeks or every other day?
<Marine salt mix is better. MUCH better. If you're serious about keeping Mollies, make an effort to get (perhaps mail order) marine salt mix.
Ordinary aquarium salt is not nearly as good. It doesn't raise the pH and it doesn't increase carbonate hardness, both critical to ensuring Mollies stay healthy. Some people make the mistake of thinking aquarium salt is a cheap alternative to marine salt mix: it is not! Marine salt mix is better.
If you live in North America or Europe, buying marine salt mix should not be difficult. As for water changes, ordinarily you should be doing them weekly, or at least every two weeks if the tank isn't heavily stocked. But when using medications, usually the instructions of the medication will tell you when to do water changes. Commonly you do NO water changes until AFTER the last dose. Finally, please use proper grammar next time (e.g., capital letters). We often just bounce back messages that ignore this rule.
You've been warned! Good luck, Neale.>

Re: black mollies, sys.  11/25/08
Hi, is Marineland Instant Ocean Marine/Reef Sea Salt the kind of salt that i need? I'm going to order in online but i want to make sure it's right.
<Yes indeed! Absolutely perfect. Instant Ocean, Reef Crystals, Crystal Sea, Kent Sea Salt, Petco Premium Sea Salt... buy whichever is cheapest in your neighbourhood. All are perfect for brackish water fish and superb for use
with livebearers such as Mollies and Guppies. Use 6 grammes per litre of water (about 0.8 oz per US gallon). This isn't very much: between 15-20% the amount needed to make normal seawater, so a box that makes 25 gallons
will actually make around 150 gallons of water suitable for your Mollies.
Cheers, Neale.>

Re: Help! Mollies/BB Gobies 11/17/2008
Hello, again,
<Hi there, BobF this time>
I had written in a couple of months ago with a concern about my Dalmatian mollies after the BB gobies I had purchased all died (see below).
<Noted>
Since then, everything had been fine with the mollies, until the other night. My adult molly, Lucky, seems to be ill - but I'm not sure if she is really sick, or just getting old. I got Lucky 10 months ago, but I'm guessing she's much older since the babies she had when I first got her are still only half her size.
Anyway, I noticed Lucky lying at the bottom of the tank two nights ago, very lethargic. I sat there watching her for a while, wondering what was wrong.
She didn't come up to eat with the others, so I continued to watch. After a few minutes she moved to the other side of the tank, hid behind a plant, then began what looked like a seizure, for lack of a better word. She started shaking her head back and forth, then rolled a couple times, then went nose down and just lay there.
<Yikes!>
I thought that was the end, but she was still breathing, and by the next morning she seemed fine. She came up to eat, nibbled on some seaweed, then went on about her business. Again in the evening, she was lying at the bottom, lethargic again, then the same seizure-like activity happened and she sank to the bottom and rested on her side. Same thing today - eating fine in the morning, seemingly normal, then by the evening lethargic, not eating, seizure. She looks fine, physically - she doesn't appear pregnant, did not just have babies, it's just her behavior that is very concerning. Any ideas?
<Alarming behavior... perhaps something internal... not treatable>
About the tank - I have a 30 gallon brackish (1.004-1.005) tank. Nitrites, nitrates, and Ammonia are all zero, pH is 7.6. In the tank I have Lucky, along with 2 "teenage" mollies, and 5 baby mollies - about 4 months old.
There are a couple Anubias plants, but mostly artificial plants.
Any thoughts would be greatly appreciated. Everyone else in the tank seems happy and healthy - knock wood.
Thanks for you help,
Amy
<Given your report of the system, conditions, apparent sophistication... health of other livestock, I do think this is "something" anomalous with the one fish... perhaps attributable/label-able as "old age"... Bob Fenner>

Black mollies... Hlth., sys.   11/14/08
hi i have two black mollies and one has white discoloration on him and i understand it could be a fungus and i should do a 50% water change and use Maroxy to help and add a tea spoon of salt to my tank but im worried for my other fish i also have guppies and other mollies and platys will the Maroxy or the salt harm them?
<Greetings. Guppies, Mollies and Platies will all do well in brackish water. Maintain this aquarium at SG 1.003 (6 grammes, about one teaspoon, or MARINE salt mix per litre of water). Understand this: aquarium or cooking salt won't help. You need to be using marine salt mix, i.e., products like Instant Ocean or Reef Crystals. These not only add salt, but also raise the pH and hardness levels. Black Mollies, and indeed all Mollies, do best in brackish water and almost always get sick in precisely the way you describe when kept in freshwater tanks.
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
Cheers, Neale.>

Dalmatian Molly 11/11/08
I have a Dalmatian Molly and I think it may be pregnant. Another person said it could have bloat, I have never heard that term before. I have tried looking at pictures on line, but my molly is twice the size. Any help would be appreciated.
Thanks,
Lynn
<Lynn, "bloat" is another word for dropsy (technically, oedema). It follows on from organ failure, and is almost always associated with chronically poor environmental conditions. The give-away clue to oedema is that when viewed from above, the scales bristle outwards from the body, so that the fish looks like a pine cone. In the case of Mollies, the most common problem is trying to keep them in freshwater. Mollies rarely do well in freshwater, and unless you're a super-expert fishkeeper willing to carefully monitor pH and nitrate concentration, just isn't worth trying.  When Mollies are kept in brackish water they are infinitely hardier and more easily maintained (aim for around SG 1.003, upwards of 6 g (one teaspoon) of marine salt mix per liter). Next up is diet. Mollies are herbivores, and a very common mistake people make is to give them standard tropical fish food. Mollies should receive such foods only occasionally, a couple of times per week maybe. Otherwise their diet should be algae, algae, and more algae. There are algae-based flakes and pellets on the market, and these are ideal. If given the wrong food, Mollies are prone to constipation, and this causes symptoms similar to oedema. Finally, there's pregnancy. When pregnant Mollies do indeed swell up, but around the abdomen
only. The fish should only look "swollen" for a couple of weeks, at which point the fish gives birth and quickly deflates down to her normal size.  Gestation is actually about 4-6 weeks, but only the last couple of weeks cause really substantial swelling. Once you've bred Mollies a few times, it's easy to recognize the cycle. Do read more about Mollies here:
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
Cheers, Neale.>

Molly skin lesions 10/23/08 Hello Crew, I would like to express my gratitude for the invaluable resource you provide. My fish also thank you for improving their quality of life. <Thanks for the kind words.> I have a cycled 20ga brackish tank with a whisper EX30 filter, a heater, a bubble stone, wisteria, Amazon sword, and horn-wort plants. <I'm amazed these plants are growing at SG 1.008! Pretty darn salty for most freshwater plants. Are you sure your hydrometer is accurate or you're using it right? Usually freshwater plants struggle above SG 1.005, though there are exceptions.> The substrate is 5 cm deep fine gravel. I have been testing the water daily with an API freshwater kit and an Instant Ocean hydrometer since adding two Nerite snails and three creamsicle lyre-tail mollies (1 male, 2 females) 2 weeks ago. As expected I needed to change the water daily for the first week to keep nitrite levels under control while the biological filter caught up with the new load. <Nitrite is toxic to Mollies in freshwater tanks, but seemingly much less so in brackish/marine conditions. That's why Mollies can be used to cycle marine aquaria, something that would kill Mollies under freshwater conditions.> My values are S.G. 1.008, salinity 10 ppt, ammonia = 0, nitrite = 0.25mg/L(before changes), nitrate = 2.5 mg/L(before changes), pH = 7.8, temp = 79 F. <Apart from the nitrite, this is all fine. SG 1.008 is actually around 13 grammes of marine salt mix per litre. In all fairness, this is far more salt than Mollies need to be happy, and SG 1.003-1.005 (6-9 grammes per litre) is ample. Your plants should do better at a reduced salinity, and you'll also save money too!> Thus far all three fish are active, gregarious, and voracious. They even take food from my hand. I am feeding ~50% Spirulina flakes, ~25% TetraMin flakes, ~ 25% freeze dried bloodworms, freeze dried brine shrimp. Both females appear to be quite gravid and I have a 10 ga tank started cycling for the fry. <OK.> I have attached a picture of one of the females showing a distressing looking (to me at least) opaque lesion on her dorsum ranging cranially from her lips to the caudal aspect of the base of her dorsal fin. <From the photo I can't really see much: but it doesn't look obviously damaged. I'd actually imagine this is simply its colouration, and not be too worried.> To me it resembles the outside of a powdered donut though not entirely white, looking rather flattish and dimpled as opposed to cottony or stringy. The other female has a much smaller area also on her dorsal aspect but it is less pronounced and encompasses a smaller area cranial to her dorsal fin. <Hmm... do honestly need a sharper image to say anything sensible.> I have attached a picture of the worst of the two afflicted fish with the hope of obtaining a tentative diagnosis. My fear is that I am dealing with columnaris or a pernicious fungal infection. I do have some background in veterinary medicine (companion animal emergency/critical care) but no practical experience with aquatic critters and I am stumped. <Well, fungus is pretty rare in brackish water tanks. Finrot and Columnaris are both bacterial infections, but neither is obviously the case here. While you might treat the tank with, for example Maracyn, do take care whatever you use is safe with Nerite snails. Copper-based medications (most anything that turns the water blue or green) can be lethal to snails.> I don't want to give arbitrary medications based on the somewhat dubious advice of my LFS. Can you tell from the picture what may be going on and advise accordingly? <Unfortunately can't diagnose the problem, if any, from these photos. Because both fish have similarly placed and coloured "lesions" I'd actually suggest that you're looking at a distinctive colouration of this breed of fish. If the fish are otherwise healthy, and the mouth and fins in particular look clean, I'd be fairly positive about their health, and basically sit back and observe for the time being. But I can't be 100% without a sharper photo.> Respectfully, Kendra <Cheers, Neale.>

Re: Molly skin lesions 10/24/08 Neale, <Kendra,> Thanks for your response. Sorry the resolution was so poor. Maybe this one is better? (I hope...) <Yes, certainly sharper. But still not seeing anything obviously "wrong". Yes, there is a white pattern leading back from behind (its) right eye over the shoulder and along the dorsal surface towards the right side of the dorsal fin. But this isn't obviously (to me) a disease as such. One complicating factor is that many "fancy" varieties of fish are extremely inbred, and you can get all sorts of genetic abnormalities. So before diagnosing Finrot or Lymphocystis or whatever, I'd be looking to see if these are merely aberrantly coloured scales or something along those lines. I'd also check to see that scales haven't fallen off. That happens sometimes for no particular reason, though it is more often a sign of fighting or physical damage, e.g., by rough handling or even (failed) predation. Conversely, I'd be looking out for clear signs of ill health, specifically loss of appetite and/or shyness. Livebearers seem (in my experience) to become very withdrawn when ill, and that's often the first sign something is amiss.> I will take a water sample to the office with me today and recheck the S.G. on one of our refractometers to compare results. <Have a sneaking suspicion you will be surprised. Swing-arm hydrometers are notoriously inaccurate, perhaps because of friction around the pivot, especially given a build-up of lime or salt. I prefer to weigh out the salt mix, and then use a floating hydrometer to double check the specific gravity. If you haven't tried it out, download my "Brack Calc" tool to see the relationship between salinity, specific gravity, and water temperature.> Thank you so much. -Kendra <Happy to help. Cheers, Neale.>

Dalmatian Molly is sick....I think (Mollienesia; the usual)   10/14/08
I have a 6mos old 10gal tank, water temp stays at 76 F, hardness 180ppm, nitrates ~10ppm, nitrites ~0-1ppm, KH at 50ppm and PH 6.9-7.2
<Way, way too soft and acidic for Mollies. Do understand that Mollies will not, repeat WILL NOT, tolerate anything other than rock hard, alkaline water. We're talking pH 7.5-8.5, 15+ degrees dH. Arguably -- and it's a VERY strong argument -- they are best kept in slightly brackish water, around SG 1.003 to 1.005. Moreover, they are VERY INTOLERANT of nitrite, so if you can detect ammonia or nitrite, and you aren't keeping them in brackish/marine conditions, that's as good as signing a Death Warrant. In any case, the tank is too small for Mollies. Even a tank 3 times this big would be marginal. They are NOT easy fish to keep, hence the constant flood of messages to WWM about sick Mollies!
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
>
We use an AquaClear 3 stage power filter. We have one each of the following; neon tetra, white cloud, sunburst, Dalmatian molly, algae eater.
<One Neon? One Minnow? These are SCHOOLING fish, and MUST be kept in groups of six or more. Please please please read up on the needs of your fish. I wonder what the "algae eater" is? If either Pterygoplichthys ("Plec") or Gyrinocheilus ("Chinese Algae Eater") you will live to regret this purchase. Both are huge animals, and Gyrinocheilus famous for being nasty, aggressive fish when mature.>
The molly was the last fish we added. At that time the water clear, we added the molly..loved the
algae on the shells. the a small algae bloom appeared. Added Algaefix and within 3 days the water was crystal clear and ALL fish were happy.
<Algae is not a problem as such. Do understand it's TELLING you something about the tank. Don't "fix" the algae, but instead concentrate on what might be amiss. Is the tank getting direct sunlight? Is the water stagnant? Are there too many fish?>
We recently moved (next door) so I took the tank down between a half and 2/3, so I could carry it over. Then refilled the tank. Added a little aqua plus which we used when we originally setup the tank. Since the move a very large algae bloom began taking over the tank, green algae. I added Algaefix again. I have noticed though when I add algae fix the molly becomes unhappy and camps at the bottom of the tank.
<Algae is what Mollies eat. They like it. Indeed, they're healthier fed on algae than flake! Besides, anything poisonous to algae will, at best, cause conditions to decline as the dead algae decays. At worst, the Algicide will stress your plants and irritate your fish. There is NO GOOD REASON to use algae killing medications, and plenty of excellent reasons not to.>
So rather than keep up those treatments I have been doing weekly 25% water changes and cleaning the filter each time. The molly seems to like the water adds, very active.
<Yes; they like clean water. Between water changes the water quality drops, and the Molly gets stressed. Do a water change, and he peps right up.>
But when I treat the algae it seems to dislike it. This has been going on now for a month. This past weekend I decided to do about a 30-40% water change, tank was VERY cloudy with algae. I also added cycle to the tank to try and address any issue with the bacterial cycle. This was about 3 days ago. Today the molly is staying at the bottom and trying to lay to it's side, when it begins to tip is catches itself and tries to resettle again, sometimes it goes all the way on its side, but rights itself each time if it begins to drift upwards. I also notice it occasionally tremors as it camps on the bottom trying to get settled.
<This is something akin to "the Shimmies", and a VERY good sign that your Molly is not healthy.>
All the other fish are very happy, except the molly. The water is still cloudy but much reduced. I changed the location of the tank. less sunlight exposure and leaving the light off most the time...Bottom line I don't know what's going on..very new to this and could use your guidance.
Cycle, Algaefix and Aqua plus are the only chemicals I have used.
<Lay off the chemicals, and hit some books instead...><<Bingo! B>>
We use TetraColor tropical flakes as their food...
<Mollies are herbivores and need algae-based flake foods. In any case, colour enhancing foods are much misunderstood and best ignored in favour of varied, balanced diet.>
Thanks in advance for any help!!!!
<Hope this helps! Please review in particular: diet, water chemistry, water quality. Maintain your Molly in a tank offering what this species need, and he should be fine. At the moment, things look gloomy. Cheers, Neale.>

Molly Problems – 10/02/08
Good Morning,
<Hello,>
I read through almost all of the information here on your site looking for answers to my issues, and as well searched the web for help to no avail. I have a well cycled freshwater tank. It is a Marineland Eclipse system 12 gal. It's been up and running since May of this year.
<Twelve gallons is next to nothing in terms of aquarium stocking -- do be extremely careful what fish you add. Even Guppies are too big/energetic for this tank in the long term. Have written much about the problems of sub-20 gallon systems here at WWM, so please do review.>
Water quality is near perfect, and I keep the temp around 76-78 degrees with a digital heater. The first fish introduced to the tank about three weeks after set-up were two small fancy fin zebra Danios.
<Too active for this tank... need a tank 60 cm upwards in length once fully grown, given their size and boisterousness. Also, they're schooling fish, so groups of six or more essential. In smaller groups they're definitely unhappy (even if you can't tell) and often become aggressive, chasing and nipping each other and their tankmates. Please do get a fish book from the library or book store, and review the needs of fish PRIOR to purchase.>
They did very well, and helped cycle the tank. About three weeks later I purchased two red dwarf gouramis. They did exceptionally well, and were thriving.
<For now, anyway... Not my favourite fish for lots of reasons.>
Finally I added two Cory catfish to help with tank clean-up.
<Clean-up is YOUR job, not theirs. Moreover, Corydoras need to be kept in groups of six or more. Few species are small enough for you to keep six specimens in twelve gallons of water. Only "dwarf" species like Corydoras hastatus and Corydoras habrosus would be viable. Peppered catfish (Corydoras paleatus) are the most commonly traded species, but at up to 7 cm long, they're WAY too big for a 12 gallon tank.>
All was well until a few days ago I decided to add some Mollies to the tank. I was told by the pet store that adding mollies would be okay, for the other fish I had were community fish.
<Again, read a book. Almost all problems in fishkeeping can be avoided this way. Mollies are FAR FROM ideal community fish, not least of all because they need very specific environmental conditions to thrive, ideally brackish water conditions.>
So I purchased two platinum Lyretail mollies, and one black Sailfin molly. The Sailfin molly died within 12 hours. She seemed fine, but then I found here floating upside down. That was weird, but I figured maybe she was unstable to begin with and the shock of the move did her in. I pulled the dead fish out and went to bed ( I leave a small red led light on at night so the fish are not in total darkness. good idea or bad?)
<Neither, but a waste of electricity so for the sake of global warming, how about switching it off...?>
So anyway, in the morning one Gourami was dead, fins eaten, and scales missing, and the other Gourami was being hunted down and eaten alive.
<Hmm... could be many things going on here. For a start, two male Colisa lalia will not coexist in 12 gallons. One will become dominant, and the other will be (at best) bullied and at worst stressed to death, unable to feed normally. Next up, mass produced Colisa lalia are of such abysmally poor quality that no-one in their right mind should buy them (at least not without a one-year guarantee!). Have written about this here and elsewhere so do review.
http://www.wetwebmedia.com/FWSubWebindex/anabantoids.htm
Thirdly, Gouramis and Mollies have utterly different water chemistry requirements, so anything suitable for one will be harmful to the other.>
By the time I realized what was happening it was basically too late for him. He was already battered, and they were relentless in their pursuit. So I pulled him out and euthanized him with seltzer water.
<That's not euthanasia, that's a horrible way to go! Where'd that idea come from? It's basically dropping a fish into an acid bath... do think back to your High School chemistry: CO2 plus water = carbonic acid. Nothing there particularly good for giving your fish a painless, rapid death. Do see here:
http://www.wetwebmedia.com/euthanasiafaqs.htm
>
The mollies were acting like a pair of piranhas. Now the next day I notice that one of the mollies lips and mouth are red and swollen with almost bloody spots at the corners of his mouth. His eyes are wide with stress, and he appears to be in pain. What is going on here?
<What's the water chemistry? Be under no illusions here: Mollies MUST HAVE hard, alkaline water around pH 7.5-8.2, hardness 15+ degrees dH. They are infinitely healthier in brackish water around SG 1.003 upwards. They are extremely intolerant of ammonia, nitrite, and even nitrate. Being herbivores, they will not stay healthy given a non-herbivorous diet. All these things are amply discussed in the literature and here at WWM.
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
In small tanks they never do well because of their sensitivity to rapid pH changes and nitrate accumulation. Even 20 gallons is too small for them, especially given some varieties will reach 10-15 cm in length. Recommend not less than 30 gallons if you want even half a chance of keeping Mollies properly.>
I left him in the tank to watch to see if the culprit is the other molly attacking him, but she never touches him. She swims near then darts away. Within a few hours this molly is dead. So I have now just one molly and my cories. Now today I notice that her mouth is swollen and pink. Her lips are bumpy rather than smooth, and she is acting weird.
<Could be Mouth Fungus (also known as Columnaris) but equally easily Finrot or even incipient Fungus. Extremely common when Mollies are kept in freshwater conditions. Just to make this point clear to all our readers -- Mollies just aren't "good" freshwater aquarium fish, and inexperienced aquarists should NEVER keep them thus. Stick them in a brackish water tank and they're tough as nails, and in saltwater tanks can be used to cycle filters from scratch! All good clues to what these fish actually want, as opposed to what we sometimes try to foist onto them.>
Just sitting stationary in one corner near the heater.
<Likely "the Shimmies", again, very common.>
I've never seen a problem like this, nor seen mollies act so violently.
<Unlikely the Mollies killed the Gouramis, though adding new fish to an overstocked aquarium could easily tip the balance such that the "surplus" fish died. That said, male Mollies are mutually aggressive, and again, that's why they need BIG TANKS.>
Can you please give me some advice, for it looks like I'll be restocking soon for all my fish have died. I am at a loss. Help! Thank you!!!
<Please, first thing you do is grab a pH and hardness test kit and establish what your water conditions are. Then go read a book of fish species, and when you see a species you like, cross-check its requirements with what you have in your tank. If you have soft, slightly acidic water, then tetras and barbs will be fine, but livebearers and many cichlids won't be appropriate. Do see here:
http://www.wetwebmedia.com/FWSubWebIndex/fwlivestk.htm
http://www.wetwebmedia.com/FWSubWebIndex/fwlvstksel.htm
http://www.wetwebmedia.com/FWSubWebIndex/fwlivestocking.htm
Now, I'll tell you that in a mere 12 US gallons your choices are extremely limited for all kinds of reasons to do with activity, adult size, sensitivity to pH changes, and so on. Avoid anything above 2.5-3 cm in length, and don't pick anything noted for being either aggressive or an active swimmer. Neon tetras, gobies, Kuhli loaches, pygmy Corydoras species, shrimps and snails are all good choices for very small tanks.>
Joanne from New Jersey
<Cheers, Neale.>

Mystery Mollie Illness? Reading   8/24/08
Hi there! Thank you so much for taking time out of your lives to create this site for us. In my ten gallon tank
<Mmm, small... volumes are hard to keep stable>
I currently have three bronze cories, one Otocinclus, two silver mollies, two Dalmatian mollies, and a Crowntail Betta ( perhaps you'll tell me it's overcrowded but I have not had any problems with nipping or bullying.) I'm having some problems with one of my female silver mollies. Her dorsal is clamped and she has a slight pink hue on the top of her head between her eyes. She also has a dusting of tiny black spots across her body and the edge of her dorsal is black when looking at it from the top. Her gills also seem a bit more pink than usual. I thought it was fin rot, but after a round of Melafix
<... not a fan. Little practical use, and can malaffect nitrification>
and Tetracycline I didn't see any improvements. I treated the whole tank but am now considering separating her and beginning anti-parasitic treatments. I was thinking of velvet as an initial possibility, but the spots seem too dark for that. All
the other fish seem fine. All advice would be most appreciated!!
Oh, and water conditions are:
pH - 7.0
Temp - 78 F
Nitrates, Nitrites, and Ammonia are all at 0
<Good>
I also add a few teaspoons of aquarium salt and Aquarisol
<Mmm, I wouldn't use this... the copper is too toxic>
every time I change the water (about 50% every two weeks) along with the typical water conditioner. It is a lightly planted tank with gravel substrate.
Thank you so much!
<I suspect the usual trouble with mixing Mollies here... Inappropriate environment. Please read Neale's piece here: http://wetwebmedia.com/FWSubWebIndex/mollies.htm
and the linked Disease FAQs above. Bob Fenner>

Sick Dalmatian Molly 5/27/2008
Hello Bob!
My Dalmatian molly has recently got a white growth (it looks kind of puffy) on its tail and right above one of its eyes. I have one other molly in with it in a 10 gallon aquarium.
<There's one problem. Mollies are very intolerant of poor water conditions, particularly pH changes and high levels of nitrogenous waste, including nitrate. In a 10 gallon tank there's realistically no way you can maintain stable pH and good water quality.>
They had fry a few weeks ago and I was getting ready to put them all together when I notices the growth. I watched him (it's a male) for a while and noticed he looked sick. He lays on the bottom of the tank unless he gets disturbed and when we swims he doesn't swim in a straight line and his body looks bent. My other molly sucked on him a few times while I was watching. I haven't gotten my water tested lately, but I'm going to get it tested tomorrow. I don't know what to do! I'm a beginner with tropical fish.
<Mollies aren't beginners' fish. They need very hard, very clean water with a basic pH. Ideally they should be kept in brackish water, and frankly they don't tend to do well kept otherwise.
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
Add 3-6 grammes of marine salt mix per litre and your Mollies health will dramatically improve.>
I was wondering if I should isolate him in a separate tank and treat him for ICH or something, or if maybe I should just let him be and see if he would stick through it and get healthy again.
<Almost certainly Finrot and/or Fungus, so use a medication that treats both. Maracyn, eSHa 2000, or equivalent. Skip Melafix type products; they're unreliable.>
This is urgent so please reply as soon as possible. I'm going to a local pet store tomorrow to ask some questions, but they have never been much help before.
If you can help me that would be great. I hope I gave you enough information.
Thanks a bunch,
Amanda
<Cheers, Neale.>

Sick molly 5/17/08
I had a female silver molly that started to swim vertically with her nose pointed upward. I had suspected she might be in labor so I waited before doing anything. Two days later, 13 fry appeared, but when I found the female she was dead. The babies, so far, are all happy and healthy in a two-way breeder, but now the male silver molly is showing the same symptoms that the female did. He swims vertically every now and then and looks as though he has to put extra effort into swimming anywhere. I started to notice an orange-ish coloring along the top of his top fin and it spread to his sides so that there's an almost metallic orange sheen to him. Just today I've noticed dark grey vertical lines on his sides. He still eats and gets around, but he's definitely not doing great. (None of my other fish; platies, tetras, guppies, snails, ghost shrimp, have any problems) I hope you can help. Thank you so much in advance.
<Greetings. By the sounds of things, the Molly has Finrot. The "orange" you're seeing is (I'm guessing) inflamed, dying tissue under attack from Aeromonas/Pseudomonas bacteria. Understand this: Mollies simply do not do well in freshwater. Yes, Mollies are freshwater fish in the wild, but for reasons to do with osmoregulation, pH changes, and/or nitrate sensitivity, they do far better in brackish water aquaria. So, with that said, you likely need to add marine salt mix to the aquarium for Mollies to be a long term success. Apart from the Guppies, Shrimps, and possibly Platies, none of your other livestock will tolerate brackish water. This is why experienced fishkeepers make the point that Mollies *are not community fish*. They never have been and never will be. But unfortunately aquarium shops stock them and sell them as community fish. So your predicament is not at all uncommon. Obviously you need to start by treating for Finrot. Maracyn (in the US) is the drug of choice; elsewhere antibacterials like eSHa 2000 should be used. Avoid Melafix/Pimafix-type things. Also read my article on Mollies, here:
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
Hope this helps, Neale.>

HELP!! I have a sick mollie! 05/08/08
Hey guys, it's Alia again! You were so helpful last time, I didn't think I would need your assistance again. I have a 10 gallon brackish tank with five mollies (I'm getting a new one though! :) I have a twenty gallon long tank setup). The pH, in my ten gallon tank, is 7.8, alkalinity 240 ppm, hardness 185 ppm, nitrite 0 ppm, nitrate 20 ppm. I know the nitrate is, currently, too high. I replaced the carbon filter last night, hoping that it would help lower the nitrate levels along with frequent water changes (once-a-week). Anyway, on to my sick mollie. Blade, my male mollie that is sick, has been rather lethargic for the past two weeks. I separated him from the rest of the mollies, with a tank divider, for a couple of days. He is now back with the others and I just noticed that he shivered and he looked like his skin was itchy. He tried rubbing against a tank ornament. I checked and he didn't have any white spots due to ick; however he swims around with
his dorsal and posterior fins sagging moderately. I know I've read about a disease with symptoms similar to this. My problem is that I can't remember what the disease is and how to cure it. Please help me save my little Blade! Thank you so much!!
<Not sure precisely what this disease is; could be "the shimmies". Do also look for signs of Finrot and Fungus. If "the shimmies", then optimal water quality, plus reasonably brackish water (around 9 grammes of salt per litre) should do the trick. "Teaspoon per gallon" amounts of salt *do not* make brackish water, and won't help. 9 grammes of salt is about 1.5 level teaspoons of salt, and that's about how much you need per litre for greatest chance of success. Cheers, Neale.>

Black molly, red protrusion... Camallanus   4/25/08
Hi,
We have a black female molly that has a red string protruding from it's anus. She was born January 20, 2008. She is in a 29 gallon tank with 5 brothers and sisters, 2 silver female, 1 silver male, 1 black female and 1 black male. There is also 2 adult silver female, 1 adult yellow female and 1 adult male guppy. We change 25% of the water on Sunday's. We can't figure out what the protrusion could be. It almost looks like feces when I feed them blood worms, but they haven't had any for a week and it's bigger in diameter. It's bright red in color and hasn't moved for 2 days. I'm thinking about pulling on it to remove it. She also doesn't have an appetite. Any information would be helpful.
Thank You,
Grant
<Likely Camallanus or other parasitic worm. Try inserting this term, and "Molly disease" in the search tool here: http://wetwebmedia.com/WWMAdminSubWebIndex/question_page.htm
reading the cached views. Bob Fenner>

Strange oozing in very pregnant Molly  4/6/08
Let me start by saying I read through your FAQ on Molly reproduction (I have the whole thing printed out and have referred to it several times since finding out I have a very pregnant molly), and tried to use the search tool. That didn't work, and please accept my apologies for this email if it turns out that this is posted already. Either my computer sabotaged me, or I couldn't figure out the search tool. I tried it several times and all I got for my efforts was a blank page. Anyway, here is the scenario. We have a 60 gallon long tank that has been running now for about 2 and a half months. We use a power filter (Aqua Clear 110), as well as an undergravel filter, and we have ammonia and PH monitors in the tank. Since we live in the desert and our water is very hard, we bought a tap water filtration system which we use for our bigger water changes.
<Don't waste your time softening the water for Mollies; liquid rock is what they like! You want hardness 20 degrees dH or more, and pH around 8. Ideally with marine salt mix added for all kinds of reasons. Your should never, ever use water from a domestic water softener in an aquarium. It has all the wrong mineral composition for fish.>
We do about a 10% water change weekly.
<Not enough really; Mollies are super-sensitive to Nitrate, and in fact pollutants generally, and they need at least 25% weekly water changes, and quite likely more if you aren't using salt (salt moderates to toxicity of nitrate).>
Just recently, when a fish died within days of being introduced, we took the fish back to the store with a water sample, which they said was the best water quality they had ever seen in the area. This might be a little more history than you wanted, but just in case any of it is relevant, here it goes.
<OK.>
For starter fish we picked out 6 silver Lyretail mollies and 6 Danios.
The very next day one of the mollies was dead (seemed to be fine the night before) and soon after a molly we believed to be extremely pregnant turned out to be a case of dropsy and though we moved her to a hospital tank and tried to treat it, being unsure what to do and hesitant, we failed miserably.
<Mollies are in fact terrible fish for "starting" a tank, because they are incredibly sensitive to variations in water quality and chemistry. Mollies aren't community fish and they aren't fish for beginners; they're lovely fish best kept in very specific conditions all their own. In freshwater tanks something like 50% of them either get sick or simply die within months as far as I can judge. In brackish water and marine aquaria they are virtually indestructible. That tells you everything you need to know about them, really!>
That left us with two males and two females, so we gave away a male to improve the ratio. The tank and the mollies all stabilized, and we had no problems until about 4 weeks ago, when the smaller female seemed to have some kind of fungus. We treated it, to all appearances successfully, but soon after being returned to the main tank she unexpectedly died. We did about a 20% water change. None of the Danios had any problems.
<This is all absolutely standard when Mollies are kept in freshwater tanks, especially if you're "softening" the water using a domestic water softener. I can't make this clearer: Mollies need hard, basic water, preferably with salt added. They aren't freshwater community tank fish.>
By now (4 weeks ago), the surviving female is extremely huge, overnight the ammonia levels are down to almost nil and practically the next day the female drops about 18 babies (they are very good at hiding so this could be an inaccurate count). We didn't have a nursery tank, but we sectioned off part of the main tank, provided floating fake plants for cover and plenty of baby food. About two weeks ago, we added 4 small catfish, 4 algae eaters (that's what the store called them, I can't be any more specific than that for the moment), and 2 rainbow sharks, with the babies still in their separate section.
<I hope your "algae eaters" aren't Gyrinocheilus aymonieri or Pterygoplichthys multiradiatus. Too big, too difficult to keep, and in the former case, aggressive towards tankmates once adult.>
All fish seem to be getting along fine, and all seem to be in good condition. The babies seemed big enough to join the rest of the fish last weekend, and we removed the partition. We're hoping there are still 18 of them, but we have yet to see more than half a dozen at a time since.
Now, the question... Over the last few days, on about 3 different occasions I noticed that the (still) very pregnant Molly seemed to be oozing something. whatever it is is perfectly clear, and can be detected only by the tiny air bubbles that get trapped in it. It is stringy and long, appears to be coming from the belly area, and judging from the pattern of bubbles looks very slimy in nature. The Molly is acting perfectly normal, eating and swimming as usual. The male, which had been busy getting acquainted with the new fish in the tank for the last two weeks, is back to chasing her around, and she is taking t with her usual patience. We tested the water and all is fine, the PH and ammonia monitors register safe levels and none of the other fish are showing any signs of this thing, whatever it is. The Molly doesn't have this ooze with her all the time, but since I have seen it a few times this week, and never before, I decided to investigate. The books we bought are not helpful, and I have not been able to find anything about this yet - which probably results from the fact that I have no idea what I'm looking for.
<I'm a bit concerned about you saying the pH and ammonia are at "safe" levels, because earlier on you've said ammonia was "almost nil". Let's be crystal clear about this: any ammonia or nitrite other than ZERO is dangerous. Period. Especially for Mollies. So these are likely stress factors. If the pH isn't at 8.0 and sticking there, the pH variation is another major issue. Either of these issues could be causing general ill health, and from the sounds of things we're dealing with that.>
I'm keeping my fingers crossed that you will reply that it's something normal, or at least fairly harmless, but I didn't want to take a chance on losing this Molly also, not to mention the babies she is carrying.
Thank you for your help,
Hannah
<Hope this helps, and good luck with the babies, Neale.>

Molly Question 03/26/2008
Hi I've got a 160ltr tank which has been going for about 10 months now, it's got mollies, platys, Endler's and guppies in it. I've had a issue before with platy's dying from the skinnies, but I've never had a problem with mollies before until now.
<What's the "Skinnies"?>
I have 6 second generation marble mollies, and over the last few days they have been feeling poorly with the shimmers and tail fin clamping. Today they seem much better, they are swimming around happily, eating and I haven't seen a shimmer in over 24 hours.
<Do check temperature and salinity, both key factors with Mollies. Given you're keeping all livebearers together, adding salt to this tank is easy and safe. I'd be going with 6 grammes per litre of water, and use MARINE SALT MIX, not "aquarium salt". The Mollies will be altogether healthier in every way, and the other livebearers will appreciate the extra alkalinity. If you have a hydrometer, what you're aiming for is a specific gravity of SG 1.003.>
However on 3 of them I've noticed what appear to be 2 red spikes coming out of them. It's not fecael matter, it's different to that, one of them it's coming from it's anus, but the other two has it coming from higher up their bodies towards their stomachs. Is this a normal thing? I've never seen it before.
<These are Camallanus worms, seemingly quite common among livebearers in both the US and UK. So I'm guessing there's an issue here with breeding and transport. In any case, you need an anti-helminth medication. See here:
http://www.wetwebmedia.com/FWSubWebIndex/fwwormdisfaqs.htm
>
I'm sorry if I'm being really stupid about this, I've have raised them since birth and I really don't want to lose them now!
<Indeed!>
Any help would be appreciated.
Annabel
<Cheers, Neale.>

Black Molly health   3/14/08
Hi Guys,
I did my research but I need a real opinion.
I have a very pregnant BLACK MOLLY in a 10G nursery tank (large pebble caves, eco complete & heavily planted with hornwort and Java moss.
<Too small for Mollies. These fish are notoriously sensitive to fluctuations in water chemistry and quality. In particular, nitrate causes them great harm. Minimum size for these fish is 20 gallons, and I'd recommend more than that. Do see here:
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
>
I just noticed last night that she has two tiny white lines (not spots) on one side and one on the other side. They're still there tonight. It doesn't look like ich (which I've seen) but I'm concerned they could be parasites. I've see her flashing against the large pebbles quite a lot in the last hour.
<Difficult to say without a photo, but fungus and Finrot are the two likely issues. Extremely common when Mollies are kept in freshwater aquaria (as opposed to brackish and marine aquaria where they are generally very hardy).>
All water tests, ammonia, nitrates, nitrates etc. are perfect. .PH, GH, KH, everything is exactly how it should be.
<Don't tell me this, tell me the numbers! For example, nitrates must be less than 20 mg/l, and nitrite and ammonia zero. The pH should be around 8.0, certainly not less than 7.5. The general hardness needs to be 20 degrees dH and carbonate hardness at least 7 degrees KH.>
The water is the right temp and is crystal clear ready for the fry. The substrate has been gravel vac'd twice in the last week and I've been doing 15% water changes (very carefully so as not to stress her) every day.
<OK.>
I would say she will definitely have the babies within the next 7 days as she is huge already so I'm very hesitant to put any meds in there unless I have to - especially as I don't know if meds would
harm the unborn fry or harm them after they are born.
<Cause no harm. Use them.>
But it definitely seems like something is wrong. I have 4 teaspoons of aquarium salt always in the tank.
<Ah, not nearly enough salt. Use MARINE SALT MIX not rubbish tonic salt (a waste of money, frankly) at a dose of not less than 6 grammes per litre (0.8 ounces per US gallon). ONLY marine salt mix raises the carbonate hardness as well as the salinity. The amount of salt you're adding is trivial and wouldn't make a blind bit of difference to the healthcare of Mollies.>
I usually get to the bottom of things but I've spent 2 hours Googling and I'm more confused than I was before.
<There's a lot of contradictory information about Mollies out there. While often said to be freshwater fish, this is really only true within certain limits. For consistently good health each and every time you keep Mollies, keeping them in brackish water is simply much more reliable.>
So I've had to email you guys.
Thanks,
John
<Cheers, Neale.>

Molly issues. Hlth., env.   3/3/08
Hello, and I hope you can help.
I've searched through the archives and I have a problem that seems to be a combination of things. I had two mollies in my ~7 gallon tank.
<Too small... Mollies are hypersensitive to fluctuating/poor water quality, and simply don't do well in small tanks. 20-gallons is the minimum. To be honest, a 7-gallon tank isn't much good for anything; even an expert fishkeeper will have trouble keeping stuff alive in there.>
The first molly has unfortunately passed, probably due to my ignorance (the pet store
did not inform me of the semi-intense care that mollies require upon my purchase).
<Not sure "intense" is the word; but yes, Mollies have very specific needs. Ignore them, and they die. End of story. Do see here:
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
Unless you are an expert fishkeeper (and forgive me if you are) then I would recommend, nay, insist, you keep Mollies in brackish water. They are altogether hardier under such conditions.>
I am attempting to save the remaining molly, but she is showing some of the same symptoms as the one that perished. They are both Dalmatian mollies. I did not have a heater in my tank, so I think the first molly may have gone into shock which may have depressed his immune system.
<Why no heater? Mollies are tropical fish, and in fact like water a bit on the warm side; 26-28 C seems to be the optimum, and certainly never less than 25 C.>
The second molly is now hanging out at the bottom of the tank. She seems hungry, but when she attempts to eat the flakes that I give her it looks like she is spitting them back out, then hungrily goes to the next flake only to spit it out again.
<Fish will spit out food if they are not hungry or don't like it. Try something else. Frozen bloodworms (not freeze dried) and algae-based flake foods are the staples for these and indeed most other Poecilia. Generic flake foods aren't really what they want/need.>
I noticed my first molly doing the same thing, but she never did until now. When she has evacuations (she must be eating something), they are generally long and occasionally have a long trail of transparent mucous-like substance trailing them.
<Evacuations? Is that a euphemism for defecation? If what we're talking about is the faeces are long, stringy and pale, then that doesn't necessarily mean disaster but it can indicate lack of overall health, constipation, etc. Lots of people forget Mollies are herbivores and feed them standard tropical flake food. This is not good for them. They need algae, algae and more algae!>
I tried giving her spinach yesterday because I read on