Marble Lyretail Molly, no data, rdg. 9/9/12
<... don't live singly...>
It is our second Molly. She seemed fine in the tank at PetCo. When we brought her home, and put her in the tank, she started acting weird. It looked like she was pooping, but it was pink in color, which we thought was weird. She was hanging out at the bottom of the tank, near the heater. Thinking she was cold, we turned up the heat to make the water a little warmer. This morning she was gone. What could have possibly happened to our Lyretail Molly?
<... shock/stress... different water qualities likely... need hard, alkaline (often brackish)...>
Our tank also contains a Dalmatian Molly and 2 African Dwarf Frogs.
<Not compatible... Read here: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
and the linked files above. Bob Fenner>
Mollies and their Care 7/13/12
<Mollies feed primarily on algae, which they graze from solid surfaces using their modified mouthparts. If you watch them graze, you can see that their jaws move in an odd way that allows them to scrape away at flat surfaces. While they also eat some small animals, such as mosquito larvae, the bulk of their diet is algae-based. Fishbase for example -- a scientific, not hobby reference -- states that the Sailfin Molly "feeds mainly on algae". Hence, while you are correct that they are omnivores in the sense of being able to consume a varied diet, it's easier to call them herbivores for casual aquarists so they know to use herbivore flake food (which includes some shrimp and fish meal, too) rather than plain vanilla tropical fish food (which is formulated for things like tetras that mostly eat small animals). For what it's worth, most other fish will at least eat, and often do better, given mostly herbivore flake food, so if you keep Mollies with other fish, feel free to mostly use the herbivore flake. All the other livebearers do better on it, as will omnivorous fish like barbs and catfish.>
I am feeding them API tropical flakes for community fish and while it does have Spirulina and other veggie compounds it is not made for herbivore fishes. I have tried to feed my 2 Dalmatian (not Sailfins) juveniles things like bloodworms and lettuce.. also peas.. they won't eat it. They do like the algae wafers I bought.
<There you go. Your Mollies will eat a range of things, and there are some things they like better than others. Think of it in the same way as with human beings -- supposedly smarter than Mollies. Every medical expert on the planet tells us we need to eat mostly plants, with only a little meat in our diet. Yet most humans given the choice go for the steak rather than the salad, even though the salad is the stuff that keeps us healthy while the steak, on the whole, isn't essential and if we eat too much actually causes us harm. And this is human beings, which as I say are meant to be clever. Mollies, given the choice, will likewise go for the tasty, easy to digest stuff. But if you give them nothing else for a few days, yes, they'll eat cooked (or canned) peas and blanched lettuce.>
I have, as stated above, 2 young (Female I believe but I read that may be a red herring if they are too young to sex) mollies and 6 fry in a 20 gallon tank. The fry were a huge surprise. My LFS advised me to cycle my tank with these fish (not the fry). Ph is 8.0, hard water, freshwater, Temp is 80 degrees Fahrenheit, Ammonia is 0.50. Nitrite is 0 Nitrate is 0. I do daily water changes of 15% twice daily. I am on day 8 of my cycle. I have plastic plants as I am terrible with plants and I don't want dead plants to add extra ammonia at this stage.
<I'd still try floating plants.>
I am feeding the fry (In a breeder net) baby food formula 3 times a day as much as they will eat and giving them small algae wafers to pick at. Fish SEEM happy, swimming energetically, eating well, no spots on the scales, gills or dermis. I am new to fishkeeping and shamefully didn't start reading about mollies until I had them. Luckily for me my tap water (conditioned) is perfect for them.
<It's salty? I jest slightly, but it's a good idea to keep Mollies on their own so you have the option to add salt if needs be; while by no means essential, it can make a huge difference to their hardiness and disease-resistance.>
Questions: 1. My mollies keep running up and down the sides of the glass "Chasing" their reflections, is this normal?
<In a small tank, yes.>
They seem like very curious fishes and I don't want them to get bored, are their things you can buy for fish for their amusement?
<Not really. Fish don't play yet they do have strong instincts. So if they need stimulus, it has to be real. Plants for hiding/exploring; water currents for swimming; members of their own species for interaction; "difficult" food for grazing (see above) that they can't wolf down. In the case of Mollies, one option is to feed less, but install bright lights so algae grows strongly, and let them eat that. In the wild they need to spend hours a day feeding this way, so have less time to be bored (or aggressive).>
Is two (going to be eight if the fry survive in a cycling tank) mollies too many for a 20 gallon tank?
<I would keep Mollies in a 30 gallon tank to be honest because they are big and they are active and they are aggressive. In any case, you won't have two for long, you'll soon have dozens, so it's worth planning ahead.>
Can I keep a single male and the females and let them breed or will this cause inbreeding problems and hurt later broods?
<It's no ideal for sure, but in reality doesn't cause any immediate problems. Perhaps best to sell on most of the fry, and only keep a very few to replace elderly adults in due course.>
Thank you for your time and answers. I really appreciate your site.
<Glad to help. Cheers, Neale.>
Help! No data 4/5/12
<Uh... read here: http://www.wetwebmedia.com/FWSubWebIndex/MollyHlthF8.htm
and the linked files above. Bob Fenner>
Re: help. More molly troubles 10/23/11
i had a pot belly female molly. from yesterday it is being settled in the bottom. what it means???
<When Mollies stop swimming, it normally means they are stressed. Review the environment. Check the following: temperature = 25-28 C; hardness 15+ degrees dH; pH 7.5-8.5; ammonia and nitrite = 0; nitrate < 20 mg/l.
Ideally, keep the environment slightly brackish, around 5 grammes marine aquarium salt per litre is good. Ensure you have AT LEAST two females per male. The aquarium MUST be at least 20 gallons in size, and ideally, more than that. Cheers, Neale.>
silver molly..... beh./sys./hlth. 9/17/11
I have a 30 gallon tank with a variety of fish. I have a Silver Molly, a black Molly, 2 various kinds of Tetras, a GloFish, and 3 Guppies. About two week ago I noticed the Black Molly constantly chasing the Silver Molly.
I assume the Black Molly is male and was chasing the Silver Molly because she is female, although I am unsure of any of their sexes to be honest with you. Within the last week the Silver Molly now sits on the bottom of the tank, constantly hides in the rock fixtures, and does not even come out to eat. Her belly does not seem to be getting fatter, since my first thought was she may be pregnant. All my water levels seem to be fine. I have live and fake plants in the tank. I use aquarium salt about twice a month, but I did recently treat for Ich that I noticed on some of the tetras. I have had the tank for about 3 months and lost a few fish in the beginning, but the rest have always done well since then. Is my Silver Moller perhaps sick, and if so how can I tell, or how do I treat her? Is it is possible she is pregnant and I just cannot tell? Or maybe has she been affected by the Ich treatment?
Thanks for you help in advance!
<Hello Sonya. Do read here first: http://www.wetwebmedia.com/fwsubwebindex/mollies.htm
You say your water levels are "fine" but that's not possible. Water chemistry that suits Tetras will be soft and acidic, or at least not too hard; while Mollies need hard, alkaline water and ideally slightly brackish water. Adding salt at a dose sufficient for Mollies won't be tolerated by the Tetras, so the dose you're giving is likely doing a whole lot of nothing at all. Fancy Mollies of the sort sold in most pet shops also prefer quite warm water, 25-28 C/77-82 F, and that's far too warm for Danios (what your GloFish is) and won't be appreciated by many Tetras either (Neons for example, like Danios, prefer 22-25 C/72-77 F). "A" Danio isn't going to be happy, and all your Danios and Tetras should be in groups of at least six specimens. Next up, Mollies are notoriously aggressive.
That's what they're like. Do read the article, reflect on what you're trying to do, and you'll see the problem and its remedy yourself. Hope this helps, Neale.>
re: silver molly 9/17/11
I guess the part that has me confused is that she has been on the tank sink I started the tank, along with all the other fish that are in there and she is just now being affecting by water temperature?
<Possibly. It's really hard to say. Mollies are genetically varied (they're hybrids of likely half a dozen species, if not more) and there's tremendous variation in terms of behaviour, hardiness, and environmental sensitivity.
By default, it's best to assume that ALL your Mollies will do best kept in warmish, hard, alkaline, and ideally slightly brackish water conditions.
No, the salt isn't 100% essential, but ALL Mollies will thrive in brackish water between SG 1.002-1.005 whereas only SOME are happy in freshwater community tanks. Whether the salt is useful in terms of osmoregulation or as an antidote to water quality problems, it's hard to say; suffice it to say that most aquarium books and experts suggest that at least keeping the option of using salt is useful when keeping Mollies. In other words, choose tankmates and plants that won't mind the salt, should you need to use it.>
My Black Molly is not affected at all. The silver Molly didn't start acting this way until right around when I started treating for ICH. When I was using the Ichguard, I was also using aquarium salt everyday because I read that it helps with gill function during treatment of the disease.
<Salt has little to do with gill function.>
So I guess what doesn't make sense to me is, wouldn't the Silver Molly be more happy now that the water was suited to their environment?
<In what way? If the Molly is being bullied, stress will override any other consideration. As stated in my article on Mollies, these fish need space, they need floating plant (or similar) hiding places at the top of the tank, and they need to be kept in groups of at least 2 females per male.>
Before that I only added salt water like twice a month. Also, I do have 6 Tetras because I was advised when I bought them that they are schooling fish, however they no longer travel in schools.
<Are the tetras all of one species? Two Neons and two Cardinals and two X-Ray Tetras won't school together. Cheers, Neale.>
Mollies, sys., gen. -
My Pregnant Balloon Belly Molly! The too
mollies... the usual iatrogenic sources of
trouble -- 07/16/10
Molly Question... hlth., gen., reading --
Missing Molly and long string like stuff
Re: Missing Molly and long string like
Thank you (Mollienesia; commentary)
About Mollies 4/26/09
Re: About Mollies 4/26/09
Molly advice 11/02/08 Hi, What a wonderful website! <Thanks for the kind words.> Two weeks ago I purchased a 70L tank <Still very "young" and likely not completely cycled, so do review ammonia and nitrite levels. You cannot keep Mollies in an immature aquarium: they are just too sensitive to nitrite, at least under freshwater conditions. Neons are marginally better in new tanks, but I still wouldn't recommend them. Best to cycle using a fish-less method, and then to add demonstrably hardy species to begin with, such as Peppered Corydoras or Zebra Danios.> and now have 2 balloon mollies (1 gold coloured male and a Dalmatian female. I had a black one but it died yesterday) 4 neons (4 have already died). One orange finned albino shark fish (1 died last week) and 5 guppies (none dead!) <Do understand that Mollies are virtually incompatible with neons. Neons need cool (22-25 C) soft, acidic water to last any length of time. Without the right conditions, they have an extremely high mortality, as you're discovering. Mollies need warm (25-30 C) water that is hard, basic, and preferably brackish. Mollies kept in freshwater tanks are staggeringly disease-prone. You need to add 6-9 grams of marine salt mix (not tonic salt or aquarium salt) per litre of water for anything like good odds of success. The carbonate and bicarbonate salts in marine salt mix harden the water and stabilize the pH, while the sodium chloride detoxifies nitrite and nitrate, rendering the conditions in an aquarium much safer for Mollies. Neons will NOT tolerate brackish water, and nor will "albino shark fish" (what I assume is the albino Epalzeorhynchos frenatum). Guppies, on the other hand, will be very VERY happy in the warm, brackish water Mollies require. So, lose the Shark and the neons, add marine salt mix, and off you go. Simple as that. None of this is hidden knowledge, and if you've been reading aquarium books *prior* to buying fish you will already have been aware of this and prepared for such things.> The mollies are definitely my favourite fish, and I am interested in getting some more females to increase the female to male ratio. I was wondering what I could do to make the best environment possible? I read that it's good to add salt, but I don't know if the neons and the sharky would survive this. <The Neons and the Shark are completely incompatible with Mollies. End of discussion. Move on. You can't combine these fish an expect "easy" fishkeeping, as at least some fish will be compromised if you make allowances for the others. If your water is warm enough for Mollies, it'll be too hot for Neons. Keep conditions freshwater for your Shark and Neons, and the Mollies *will* get sick every five minutes. I'd encourage you to read this article on Mollies, possibly the most misunderstood fish in the hobby: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm I think Mollies are lovely fish, but I DO NOT recommend them for beginners or community tanks. Their mortality rate kept this is horribly high.> Also, since the death of the black molly yesterday, the male has been constantly harassing the female, I'm worried that he's going to kill her. <Unlikely to kill her, but is she happy? No. She will be stressed and prone to miscarriages, which surely is about as objective a measurement of the "happiness" of a pregnant animal as any. Adding more females, and especially adding floating plants or tall plants is very useful.> Additionally, all of the guppies have started chasing the female molly and nipping at her underside, this is odd as it never happened before today and they are a lot smaller than her! <They are likely eating baby fish as they are released. Many fish learn this trick. Again, adding plants helps. Live or plastic, as you prefer.> She has stopped swimming so much and now just tends to hide; I'm very concerned for her. Additionally, for about 20 minutes today, she was doing what looked like pink/black poos every 30 seconds or so; were these dead/prematurely aborted babies? <Could well be; stressed Mollies will indeed miscarry. The embryos are typically silvery-white with obvious eyes. The colour of the feces tends to depend on what you're feeding them. Being herbivores, I trust you are giving your Mollies a diet based primarily on algae flake (Spirulina, sold as "livebearer flake") rather than standard fish food, which isn't particularly good for them.> Thanking you in advance! Gemma <Hope this helps, Neale.>
RE: Molly advice (Environment; repro.) 11/03/08 Thank you for your advice, I have purchased some tall plants, 2 female mollies, a breeding tank and some Spirulina flakes! I was wondering, you said I needed 6-9g of marine salt per litre, now my tank is a 90L (not a 70L as I originally said) That would mean I need at least 540g of salt as a minimum??!! <Let's start at the low end of the salinity range. A 90 litre tank will need 90 x 6 g = 540 g. But that's added to the whole tank. Don't do this all at once! Start by doing your regular 25% water changes, and replace old water with the slightly brackish water. This way your plants and filter bacteria can adjust to the elevated salinity. You might also want to invest in a hydrometer; a basic floating glass model costs about 5 UK pounds. You're after a specific gravity around 1.003.> Does that sound correct? Also, how do I know when to put my female fish into the hatchery? <You never, EVER put Mollies into breeding traps. It stresses the heck out of them. Despite advertisements to the contrary, these traps aren't much use and are mostly a waste of money. At best, you can put very small livebearer species in them (like Guppies) but Mollies will, at best, jump out, and at worst, the female will miscarry or otherwise damage herself.> I don't want to keep her there for a month! <Put things like Indian Fern in the tank; the newborn fry will swim into these floating plants where you can catch them in the morning and put them in the trap or a breeding tank.> Thanks once again <Cheers, Neale.>
Molly very aggressive, reading 8/9/08 I recently added a marbled Molly to our 10 gallon tank. <Mmm, I'll comment that this is too small a volume to be viable...> It seems that our Molly is a bit aggressive and the dominant fish in the tank. <You only have one? A male?> We currently have 2 African Dwarf frogs, 4 neon tetras, <"Like" different water quality than Mollies> 3 zebra danios, one female red wag swordtail and a golden algae eater. Two of my swordtails died as a result of the Molly (one male and one female). Now my remaining swordtail hides all the time. Is this common. <Mmm, yes> I worry as she does not even come out for eating. Should I take my Molly out of the tank? I am still a novice as I have had my tank about 6 months. Thanks for any advice. Jennifer <Please read here: http://wetwebmedia.com/FWSubWebIndex/mollies.htm and the linked files above... Bob Fenner>
Mollies... comp.? 01/22/2008 I am thinking about getting some more fish. What kind of fish would go good with Mollies? Some of my Mollies bowl movements are long. Are they okay? <Read here: http://wetwebmedia.com/FWSubWebIndex/mollies.htm and the linked files above. Bob Fenner>
Re: Black Mollies 2/16/08 Thanks Bob. Yes I did add some hornwort and a little driftwood in the last few days. Food has been as normal (flake, Tubifex worms, algae wafers and shrimp pellets). <Good.> I'll raise the temperature and keep an eye on them. <can make a difference with Mollies.> The juvenile Black Molly was a mercy rescue from a pet store so wasn't researched like my other fish - I looked in a tank and saw the little guy swimming for his life (probably from his parents) and took pity. I realized soon after that he was in fact more of a brackish fish but he seemed to be doing fine till the flashing. <Adding small amounts of marine salt mix (say, 3.5 grammes per litre) will make a big difference for the Mollies but is perfectly within the tolerances of other livebearers. In fact many livebearers will thrive under such conditions. So creating the brackish conditions isn't necessarily a bad thing.> I'll look at these links now. Thanks again Bob. John <Cheers, Neale.> <<Thank you for the follow-up Neale. RMF>>
Mollies... repro., gen. 12/31/07 Thanks for all of the help but I just thought of a couple more questions. When you buy fish at the pet store some people say that they are most likely pregnant; is that true? <If males and females were mixed, then yes. The best aquariums stores keep male and female livebearers apart, but unfortunately less sophisticated stores do not.> Do you happen to have a couple pictures of male and female mollies? <The top two photos of Mollies on this page are males: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm It is REALLY easy! Seriously, if the anal fins of your fish all look the same, you probably only have one sex. Make sure you are looking at the right fin for a start. It's the unpaired fin on the bottom of the fish, close to the anus. On a female, the fin is obviously triangular, just like the anal fin or any other fish. On a male, the fin is a long, narrow, tube-like structure that is bent up against the body most of the time. When the male attempts to mate, he pulls the anal fin forwards, effectively forming a structure like a mammalian penis.> I keep on looking at the anal fin and I just can't seem to get it. <Look closer...> It all looks the same to me. <Really...?> Some people say that all mollies are aggressive, but when I watch my fish only one of them (the long one) is aggressive. <Male Mollies vary in aggression, but at their worst can be very troublesome.> What fish are compatible with Dalmatian mollies that I can get at my local pet store? <Mollies are generally easier kept in salted water at SG 1.003 upwards, so choose things that tolerate salt. Guppies, Orange Chromides, Monos, Scats, Archerfish, Violet gobies, Bumblebee gobies, Colombian shark catfish, and so on would all make superb choices. Mollies also do well in marine aquaria, so that's always an option! Avoid fish intolerant of salt such as Gouramis, barbs and tetras. Cheers, Neale.>
Mollies, English, reading 10/19/07 hello, this is my first tank. I have a 55gallon freshwater tank. i have one black molly, one Dalmatian, 2 balloon, one white, one gold, two tetras, <... like very different water quality> 3 frogs and 2 catfish. I had a swordtail which suddenly died last week. the gold molly is staying to herself and kinda shaking around. the white molly is chasing the Dalmatian molly around a lot and being quite aggressive. I don't know how to determine if they are mating of which mollies are female and male. please help Xiomara <Please read: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm and the linked files above. Bob Fenner>
Some Molly Issues... 10/12/07 Hi folks - very nice forum, full of good information and eats up a lot of time digesting all the advice! I have some issues with my mollies - firstly I'll run through my setup: 1 Marble Mollie (Female) 1 Traditional Mollie (Female) 1 Traditional Mollie (Male) 1 Silver Sailfin Mollie (Male) 2 Pleco (Suckermouth 2-3" maximum) 60L Tank, 25'C Bogwood x 2, Java moss and some other traditional plants with fine sand ground and Tetra carbon filter. <60 litres is too small for mollies. You'll have problems maintaining the zero nitrate conditions they need, and the sailfin mollies won't grow to full size.> Now onto the issues... The tank completed it's cycle about 3 weeks ago, during which these fish were in a smaller tank. However on re-integration back into this tank, all the Mollies all flick themselves off objects, be it airstone tubing, sand, bogwood or the filter. <Sounds like incipient whitespot (ick). Look for small white spots.> They also speedily swim to the surface and splash their tailfin on the surface, making loud splashes. I've checked closely for Ich, and they all seem clear. <Ah, but whitespot can be on the gills, and in this case you won't see it.> The water has just had a 40% change yesterday (it was going cloudy, so I replaced the filter cartridge and did a thorough syphon of the detritus and food remnants). <Hmm... I don't recommend changing biological filter media unless absolutely essential. What sort of filter media are we talking about here? Obviously, replacing biological filter media re-sets the cycling process to the start. Carbon is redundant, and Zeolite shouldn't be required in a regular, properly maintained aquarium.> Is this anything to worry about? <Odd behaviour should always be observed closely.> Secondly, the Sailfin male is very aggressive towards the other fish, and at least once a week will push the other male (who is actually bigger than the sailfin) in the corner, and generally stress him out. <Completely normal. Male mollies are aggressive. In a 60 litre tank, the dominant male will eventually batter the others, if not to death, then into severe stress.> However, the Sailfin sometimes when hanging in the water will slowly tilt upwards, until it is facing directly upwards. None of the other fish exhibit this behaviour at all. Is this something to be concerned about? <Sailfin mollies have a distinct adaptation to living in low-oxygen waters (such as brackish water ditches in the wild). They orient themselves head-upwards, and suck the surface layer of water in the mouth and across their gills. Most other livebearers don't do this. If your sailfin is doing this repeatedly, check water quality.> I am gradually adding small amounts of marine salt into the water (not too much as I'm aware that the Pleco's won't appreciate it) as I have been doing for 2 days now, in an effort to rectify this issue and the flicking issue, is that futile? <Treat for whitespot/ick using a standard medication of some sort. Quicker and easier. Common Plecos (Pterygoplichthys spp.) are fairly salt tolerant, and with care will do well at SG 1.003. This should be a high enough salinity for your mollies. But long term, I'd swap out the Plecos for a true low-end brackish water catfish, such as Hoplosternum littorale or (the true) Hypostomus plecostomus. These are fine up to SG 1.005. You can of course keep large mollies with brackish/marine cats such as 'Arius' seemanni and Mystus gulio.> Thirdly, I have these 'Hikari Tropical' Algae Wafers, made up of everything (it would be a super food if it was for humans I reckon). I usually drop one in and leave it for the Plecos, however I've noticed that the Mollies eat it too. Further to this, could these wafers be responsible for the water going cloudy? <No, these won't make the water cloudy by themselves. They are of course excellent food for plecs as well as mollies. Both species eat a lot of algae and plant material. Water cloudiness comes from three different things: silt from unwashed gravel, bacterial blooms during the early phase of cycling, and overstocking (and it's associated hazard, overfeeding).> On a separate note, I have a smaller 30L Tank downstairs which has 5 Female Guppies, 2 Male, 3 Neon Tetras and 1 baby Mollie - the Guppies are giving birth this week, but the fry seem quite large - are the fry at any risk of being eaten despite seeming too big for the Guppies? <Some will get eaten, yes. Depends a lot on floating plants. If you have lots of floating plants, most fry should be fine.> I don't know how I would catch them either - they are well hidden in the Java Moss, and they would probably pass through my smallest net's gauze. <I catch fry with small plastic cups, rather than nets. Turkey basters can be used, too.> Thanks for any assistance! MPH P.S. if you could email me the link if you update the FAQs with my Q+A that would be most helpful - if not too busy, a reply would be super too, cheers! <Cheers, Neale>
Re: Some Molly Issues... 10/12/07 Thanks for the fast reply - the filter cartridge I replaced was merely the carbon cartridge in my 'Tetra Aqua Art 60L' tank - the bacteria grow in the other elements of the filter itself, so the Cartridge is alright to replace (or so Tetra proclaim). <Indeed. Carbon can be changed as often as you can afford. Certainly, carbon stops doing its thing after a couple of weeks. But personally I consider carbon useless in the average community tank. Water changes are more effective at removing pollutants, and you can replace the carbon's space with more biological media. Carbon is cheap, sounds technical, and thus gets used by manufacturers to sell (at a high price) what is basically just charcoal.> I note that you said that 60L was too small for Mollies - what is a good size tank for them in this case? <Depends on the mollies. I'd keep Shortfin varieties in something around 90 litres, and Sailfins in something above 150 litres. Sailfin mollies should exceed 10 cm in length, and potentially up to 15 cm depending on the species. They're big fish.> Thanks for any assistance, Matt <Cheers, Neale>
Mollies, children on the Net 5/25/07 hi <Hi> everyone, I went to the pet store a few weeks ago and bought one male black molly, one female Dalmatian molly, and one orange male fish with a black tail. I think my Dalmatian molly is pregnant, she wiggles a lot when she swims and has a hump in her stomach. Should i put in some molly bright? <Maybe> she was also kept in a tank with males. If she is pregnant when should I put her in a divider? please help! Kyleigh <Please read here: http://www.wetwebmedia.com/FWSubWebIndex/mollydisfaqs.htm and the linked files above. RMF>
Using WWM... sexing Mollies 5/8/07 Hi I just bought some silver sail-fin mollies and one of them is a male and the other is a female, but my question is how can you tell if the female is pregnant or is it just her body structure that cause her to look plump??? p.s. hope you can send me a picture so i can tell the differences!!! :) <Please read here: http://www.wetwebmedia.com/FWSubWebIndex/mollyreprofaqs.htm and the linked files above. BobF>
Overstocked Aquarium? Molly Qs 7/24/06 Hi. I have a 10-gallon freshwater aquarium. Without getting too off topic, I hope, on a recent trip to GA to visit my mother (I live in AR) I unexpectedly delivered a premature baby and was (obviously) unable to maintain my tank. <!?> Many of my fish died *sniff*. What remains is as follows: 1 green tiger barb (it was his schoolmates who died), 1 Kribensis cichlid, 1 lyre-tailed molly (added post-death), 1 striped spiny catfish (also added post-death), and 1 golden algae eater (I am now aware of your take on these and am considering its removal). I was hoping to add balloon mollies, but am unsure of 1. how many to add and <One... a female preferably... two females... or a trio, with one male...> 2. whether they will get along with my barb. <Should if there's room> Also, as I am more experienced with the barbs, I was wondering if there is anything especially significant that I should keep in mind concerning the keeping of the balloon mollies. Thank you. <Mmm, please read here: http://wetwebmedia.com/FWSubWebIndex/mollyfaqs.htm and the linked files above... like different water quality than the Krib, need vegetable material in good quantity in their diet... Bob Fenner>
Use of UV Sterilizer on Molly Fry tank Hi all, I was thinking about using a UV Sterilizer for a Black Molly rearing tank. My reasoning is that it would be an extra form of protection for the fry considering how delicate & susceptible to disease they are. What do you think? Good or bad idea? <Would help, wouldn't hurt> Also how is a UV Sterilizer connected? Does it run independently or does it have to be attached to a filter or something? Thanks. The MollyMan <Needs a fluid-moving source and electricity. Please see here re: http://www.wetwebmedia.com/UVFAQs.htm and the linked files above. Bob Fenner>
Molly Behavior while pregnant... no useful env. info. 6/17/06 I have a pregnant Dalmatian molly and a male that wont leave her alone. <Common... good to have a better sex ratio (more females), larger systems with decor... plants...> I separated her for 4 days and no fry. I also have 2 female mixed mollies that look like they are also pregnant and today both of them started laying on the bottom of the tank on the rocks. Is this normal pregnancy behavior? <No> Should I put the Dalmatian molly back and put these two in the breeder's net? Fry are new to me...so, any info is very much appreciated. Thanks. <... not possible to give advice with the information presented. Please read here: http://www.wetwebmedia.com/FWSubWebIndex/mollysysfaqs.htm and the linked files above. Bob Fenner>
Mollies... - 03/13/2006 Hi I have a question about my mollies. they are baby mollies and they are about 2 centimeters small and I was wondering how many I could fit into a 5 gallon tank <Please see WWM: http://wetwebmedia.com/FWSubWebIndex/fwlivestkindex.htm re Mollies, Systems... Bob Fenner>
Molly, new additions - 03/13/2006 Hi again! sorry to bug you once more but my molly has worsened her bright yellow color is almost gone she is just about white so today I noticed that she had begun to show signs of a cottony white substance on her body and tiny white spots on her fins and tail. I went and bought Ichaway assuming that's what it is I dosed her and let her be. I actuality she seems better she is swimming about and eating quite normally Is what Im doing okay? if not what else can I do? Oh yes is it absolutely necessary that mollies have salt in their tank? Well in other news one of my female guppies died I think she may be the mother of the seven tiny fry I found later I am quite excited but how do I tell what kind of fish the fry are? One last question how man fish can I put into my ten gallon? I want twenty-one total they are all small fish livebearers is that okay? I hope so... Thank you in advance -Maria <Please read here: http://wetwebmedia.com/FWSubWebIndex/mollydisfaqs.htm and the linked files above. Bob Fenner> My Dalmatian Mollie has Popeye!!!!!! What do I treat it with!!?? Don't know what the water is like, so sorry! 2/24/06 <... see WWM re Mollies, Pop-Eye... Bob Fenner> Help needed about my mollies ... NNS - 02/20/06 Hello! I am Atif, i am a beginner about aquarium fish. I have 2 gold fishes and 2 koi or may they shubunkin. I have 3 female mollies and 1 male. <The mollies and the goldfish/koi should be in separate systems...> I don't know about a red one whether its a molly or a platy. That platy of molly (female ) attacks both koi and gold fish but not other mollies. One white female molly remains at the top just searching for the food i think and when the male comes at the top it chases her. That black molly male keep chasing the other black female and just i think taps to its anus of the female with its mouth ( i think it is that ). <Normal behavior... reproductive> Now how do i know that one male is making pair with a female molly. Do the mollies and platies do mate with each other. I cannot afford another tank. My current tank is 2.2 long and 1 feet width and 1.5 cm high. Please tell me some instructions on how to make my mollies and other fishes do live good with each other and i also have 2 guppies in the tank. Can i put one more pair of the mollies in the tank. I mostly feed once in a day. I have put a PVC pipe at the gravel to act as a cave for mollies and guppies. But only once i a day they do in the cave for 2-3 seconds. Also i put some plants to the aquarium and my goldfishes ate there leaves and then after some days they even broke into pieces from there stem and now that broken stems are floating at the top. Do i remove them or not. Also do i clean my sides of the tank mostly or i leave them to have some food for the mollies like algae. Remember my mollies have only taken 2 weeks in the tank. How long they will take to give birth to fries and how do i know that they are a pair or what things they do to do sex with each other. Thanks a Lot. I am having trouble with this hobby at the start and don't want to finish this. I need your serious advice <Likely separating out the "pond fish" (goldfish, koi) will give the livebearers enough space to reduce aggression here. Separate them. Bob Fenner>
New Mollie 10/17/05 I'm new to fish. It is a black, gold and white molly in with a guppy. I had no bottled water at room temp but HAD to change the nasty bowl, I think I made the h2o either to hot or to cold. He is just kind of sitting around, usually very active. I did put a little aquarium salt in it. What should I do? I really like this fish. He's a great OU fan named Boomer and his guppy buddy is Sooner! Thank You. Holly <Hi Holly, I would start by reading the following article on setting up a freshwater aquarium, it sounds like you may need to upgrade from a bowl to a fish tank, also there is no need to use bottled water, you can pick up some water conditioner at the local fish store and used conditioned tap water. The water added to a tank during a water change should be the same as the water in the tank. http://wetwebmedia.com/FWSubWebIndex/fwset-up.htm. Best Regards, Gage>
How long are silver mollies pregnant? WWM I have not been able to find this on the internet and my local pet shop is not sure. I have a Silver Molly that I believe is pregnant but I was wondering how long before we should have babies. I have put her in a small breeding tank to make sure that the male will not bother her. Any advise you have to offer would be so welcomed. Thank you Kimberly Jones <Please read here: http://www.wetwebmedia.com/FWSubWebIndex/mollyreprofaqs.htm Bob Fenner>
Sick Mollies Ok... I just noticed the spots on two Mollies in my fish tank today. I introduced a new Molly six days ago. That one was a birthday gift for my four year old. I can't kill these fish they are his babies. I tested the ammonia, pH, and nitrates about a week ago and everything checked out ok. I checked them today and the ammonia and pH spiked bad and the nitrates are perfect. I just did a 25% water change and put Wardley WaterCare Ick Away in my tank with a half dose of ammonia eliminator as per the pet store. I didn't realize till after I put in the ick away that it says don't use with tetras and I have two of those too. AM I GOING TO KILL THEM? <These medications that are based with malachite green are very toxic to tetras, catfish and some loaches. You probably have introduced ich into your tank with the new molly.> The tetra's don't have spots but cant they still be affected by the Ich if the other fish have it in the same tank? < They will get it too . They are just not showing any symptoms yet.> I do have a fish bowl I could move them to but I am new to this and I just don't know... could someone please hurry and tell me what I am doing wrong, or right for that matter, to my poor fish? < You could add some carbon to the filter and that would remove it too. Do a 30% water change, vacuum the gravel and change the filter. Once the medication is gone I would get some rid-ich II by Kordon that is especially formulated for sensitive fish. Follow the directions on the package. After treating I would add carbon to remove the medication and then add some BioSpira to get the bacteria going for the nitrification process. Go to Marineland.com and see Dr. Tim's Library for an article titled " The First Thirty Days" for info on the ammonia problems.> The infected ones also lay a lot on the bottom of the tank and only get up to say hi when I open the lid cause they are such cute friendly fish... I'd really hate to lose them :(. Please help me with any ideas. It's a ten gallon tank been running about two or three months. Total of three little mollies two little tetras and a little algae eater. Plants, rocks, etc. It has a bio filter wheel thing, do I need to do anything to that since I don't believe it has charcoal? <Remove the BioWheel when medicating so it does not kill the good bacteria on the wheel. Store it in a damp wheel in a container with aquarium water. You can also get rid of the ich by increasing the water temp to 82 degrees for awhile. It sometimes stresses the fish so you need very good aeration.-Chuck>
Molly questions I have a molly that just gave birth to a fry. I have the babies separated. I was wondering how long it with take for them to mature and joining the rest of the community (tetras and mollies). Also, what do you recommend feeding the fry? -Tara <Please read here: http://wetwebmedia.com/FWSubWebIndex/fwlivestkindex.htm. Scroll down to the livebearer, Molly FAQs archives and read re. Bob Fenner>
Balloon Mollies I have read a lot of your Q & A's about mollies, not all of them, but enough to figure my question is not answered. we are first time tank people, have had our tank about a week. we bought 3 female (that's what I told them to give me anyway) balloon mollies yesterday. I was wondering if our 10 gallon would hold about 5 females, a small bottom feeder and 1 or 2 of those small brown frogs. <Should be fine> it seams like a lot, but it also seems like everyone else is trying to breed, we are not. from the sound of it constant baby flow is the cause of high levels. <Of?> we just set the tank up recently and of course are going to watch it for about a month before we start adding (slowly), but with weekly water changes and frequent testing I think its possible. am I full of nonsense? <No... the slow, careful approach is best here> honestly we will probably be getting a larger tank in the future, but with only 4 or so fish I think it would look kind of bare. also another question, I know pregnant mollies and tanks with males and females nip at each other, but my 3 are supposedly female and they are doing it frequently, especially to one in particular. is this natural or do I have a male or 2? <You could or not... the spawn (they likely will... can/do store sperm in their tracks) will likely produce some males> thank you very much for your time, I hope that I did not ask anything ridiculous that you have answered more than 20 times. have a wonderful day! Jackie <Thank you my friend. Bob Fenner> Sick Dalmatian molly I looked through the other questions, but didn't see anything quite like this. I was changing the water in my tank today (7 gallon) and had put my 2 Dalmatian mollies (1m, 1f) in a "goldfish bowl" while I did a partial water change in the tank. (The water in the bowl was straight from the tank.) In the bowl, I noticed the male was starting to spaz out. He would be swimming normally and then just jerk as if he was being electrocuted. I assumed it was due to the pH of the water being off (which is why I was doing the water change.) I have since returned him to the main tank and he is now lying on the bottom of the tank, barely moving. His side fins are constantly flapping at about the same speed as if he were stationary in the tank. One of my other fish was acting this way a few weeks ago, but once I neutralized the pH, he was better. My real concern is that it appears as though the molly has a broken bottom lip. His bottom lip is bent completely down and away from his face so that his mouth is stuck open. <Yikes... sounds like it got whacked on the bowl's edge while it was zooming about> He did not eat when I fed them and it didn't look like he even attempted. I was going to pull him from the tank and see if I could bend his lip back up but I was afraid of injuring him further. Can you tell me what is happening to my poor fish? Thanks in advance! <Thank you for your clear writing... I think you are correct in that your Molly did just "flip out" with the moving, injured itself. I do hope it will self-cure... there is naught else that I would do. Bob Fenner>
Mollies and Snails WWM Crew, First, I must say your site has been very informative. I've learned so much! I have read plenty about Mollies etc, but I have a couple concerns re: my mollies. I currently have 3 of them. 1 silver molly (M), 1 silver lyretail (F), and black molly (F). My concern is with the two silver mollies. I did read that it is not uncommon for the male to chase around the female trying to breed. However my male is NONSTOP harassing the other silver female (she's pregnant too), and rarely messes with the black molly. Is there a special reasoning behind that? <Mmm, no... or not really. Some males are just like this... having more females, more "other" fishes, plants, other decor to break-up the physical environment... helps> I am worried that he will just wear her out, but I don't want to stock my tank with more females as I am already taking care of 16 fry as it is. Any ideas on the best way to handle this randy boy?? hahaha <Isolate him... at least for a while... perhaps in a floating, plastic colander if you don't have another tank> Second question... When is it safe to put the fry back into the larger tank with the adult mollies without the risk of them being eaten? <When they're "big enough" to not be consumed> I have 2 that are about a month old, but I don't want to take them out of the net too prematurely. The others are only a day or two old. Do you judge based on size? or age? <Size> And lastly (are you sick of me yet? haha), about a week and a half ago I noticed a small snail in my tank. Have NO IDEA how it got there as I sure didn't buy one from the store!! Then, when doing a water change the other, came across ANOTHER one that was twice it's size. I'm assuming it was under gravel somewhere because there's no way you could miss it otherwise! How do I know if it's ok to keep in the tank and breeding of snails etc?? I do NOT want more snails!! I have looked at the info on this site re: snails, and haven't come across one that looks like mine. Is it better to wait till they're more grown to determine the type of snail? And just out of curiosity... any ideas on how snails got in my tank? <Come in... with fish purchases in the water, some live foods... can be eliminated in a few ways, but not likely a problem... perhaps a help in keeping your tank clean... Not harmful to your fishes> Is it possible they hitched a ride on the fish as tiny lil thingies on them? Sounds crazy but, I have no other clue as to their appearance! Thank you so much in advance for any help you can give! I will continue to research your site for more information. It's a great tool!! Sarah <Thank you for being part of it. Bob Fenner>
Breeding mollies Hi, I have a numerous amount of female and male mollies in my tank and I have been trying to breed them forever. They haven't had babies yet. Now I am looking at a female Dalmatian molly I just bought about a week ago. It looks a little bit fat and I have a net breeder I can put it in. I just don't know when to put my Dalmatian into it. I don't even know if it is pregnant. Can you tell me how it would look, act, or any sign to where I would know if it was pregnant or not? <Please read here: http://wetwebmedia.com/FWSubWebIndex/fwlivestkindex.htm. Scroll down to Mollies... read the FAQs posted. Bob Fenner>
Re: Breeding mollies <Live bearers get rounded bellies and then a black area appears in the belly area before the tail.> I found that on your page that you told me to look at, and I was wondering if that is all I need to know about my molly. <Is it? If this satisfies you in terms of knowing... so be it. These are the two best descriptors/indications of imminent birthing... Bob Fenner>
Cross breeding mollies Hi I had an odd question and was hoping you could help me. I have a black molly, several Gouramis and a tri color shark in a 40 gallon tank. I have had the molly for about 1 and 1/2 years, and all of a sudden she is having babies. How is this possible? I have never had any babies before (I know it was her as I saw her have a few of them) nor have I ever had any other molly in the tank. I did have 2 platies in the tank for about two weeks while my 10 year old's tank was being repaired but that was several months ago. Could they have "cross-bred". Thanks Michelle <Mmm, platies and swordtails can/do cross-breed, but I have not heard of a case of such breeding with Mollienesia... all livebearing fishes can store sperm in their tracks for a period of time... but a year and a half? Unusual... the reproductive behavior and physiology of the several Molly species is involved to put it lightly... there is even an "Amazon" Molly that produces haploid offspring... not using sperm genetically... Bob Fenner>
Chocolate Salty Mollies.. >I have been reading your Molly FAQ's. Regarding adding salt to the Molly tank---- 1-- How much salt per gallon? >>You'll want to measure with a hydrometer, I prefer a lab grade float for accuracy and decent price. Mollies can "swing both ways" - this means they can go from completely fresh water to completely marine environs. >2-- Is regular noniodized table salt OK. >>I wouldn't, I would use a sea salt mix. The utility of non-iodized salts for the table is purely for medicinal/prophylactic treatments. Also, don't make the mistake I did the first time I swung some mollies to salt - I did it too fast (in just a few hours) and one "popped" (looked like a pine cone, then shimmied, shook, and died. Boy did I feel AWFUL!). >Thanks! Rick >>You're welcome. Marina
Mating Male Molly Mishaps Hi, have a Dalmatian male Mollie and he seems to be attacking my female black molly. <Sounds like he is trying to mate. This is fairly common behavior in livebearing fishes.> Her fin on the top of her body seems to be all torn up now that this is happened. He did this to the last female Mollie I had that was black, and to one of my other fish. The other fish and the last female I had died because of this. <Sounds like you should consider relocating him or not purchasing any more fish!> Why is he constantly doin' this, and should I take the male out of my tank and put him in his own? <He is doing this probably because he wants to procreate. To multiply. To breed. To reproduce. To propagate. To generate more mollies. To carry on the species. He is being met with resistance from the females, and continues to harass them to fornicate. This harassment is ultimately leading to their deaths. It is common practice among livebearers breeders to include several females to every one male of a species to disperse the aggression. Good luck, Mike G.> <Excellent alliteration of the title, Mike!>
GOOD GOLLY MISS MOLLY Hello! I have recently started up a tank, and there are a few mollies. I do not know how to sex them. One of them was really fat, and I thought it was pregnant, turns out, it is a balloon belly.. Well, it has been hiding for 4 days now. I figured maybe it was a she and was about to give birth. She was eating a little here and there, and mostly stayed hidden. This afternoon, I got a breeder net and put her in it. A little while later I noticed a black molly was getting fat and had a clearish something coming out of it. (like a poop rope, only clear) So I stuck it in the breeding tank too. Well, the balloon belly started chasing black molly around and coming up under her like they were mating. So, I took the balloon belly out, assuming now that she is a he. The main question is, if it is a he, then why would he be all sulky and hiding? ~Charly~ < To sex mollies as well as other live bearers you need to look under the tail at the anal fin. Females have a regular looking triangular fin while males have a long tube like fin that has been adapted to insert into the females to fertilize their internal eggs. New fish may take awhile to acclimate to their new surroundings. There is a pecking order to be figured out in almost all tanks. If your fish was alone then they would feel more comfortable in schools or small groups.-Chuck.>
Black molly care Hi I hope you can help me. I inherited a fish tank with black mollies in it only 5 days ago. In the process of getting the fish tank cleaned I lost 3 of the fish. Not bad for a beginner! They all seemed to be doing well until the biggest one in the tank started to hang out the bottom and hide under one of the rocks. I believe it's a female by the shape of her anal fin. I feed them twice a day; in the beginning she came up for the food now she doesn't even do that. I wonder if she is pregnant. These poor fish were abandoned in an apartment and left to die so I took them in. I know absolutely nothing about taking care of fish but, I'm learning quickly. THANK YOU BARBARA <Please take a read here: http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm regarding proper biological filtration... and here: http://www.wetwebmedia.com/FWSubWebIndex/mollyfaqs.htm re Mollies... I suspect your new tank is simply not "cycled", and possibly that the mollies water is not to their suiting... Bob Fenner>
Deceased Dalmatian Molly Hello! It's me, Walt again. I am really sorry to bother you for the hundredth time. My wife and I woke up this morning to find one of our Dalmatian mollies deceased and stuck to the filter intake. (Actually, we did not notice it right away and then all of a sudden I looked up and saw it on the intake... Don't know what to make of that.) <Me neither> As you may remember, I have had my 44 gallon pentagon up and running for about nine weeks now. I started changing five gallons of water weekly two weeks ago, as recommended. I test my water regularly, and since I added Turbostart 700 the first week, my parameters have remained stable: pH 7.8; Ammonia 0; Nitrite 0; Nitrate 20ppm; Hardness 160ppm CaCO3. I tested this morning after finding the dead fish and found the same results. I cannot figure out what happened, as she was fine last night. I have some possibilities... I started with 16 fish after adding the TurboStart. (2 Diamond tetras, 2 Beacon tetras, 2 platies, 3 pairs of differing mollies, 2 kissers, and 2 red velvet swordtails). During the first six weeks, I lost one kisser due to his aggressive brother, after which I returned the offender. Other than that, I let them be until I was sure the tank was stable. After six weeks I started adding more fish. First, I added the two Dalmatian mollies, two platies, and two Botia darios to help with the occasional snail. I noticed some very aggressive behavior following this change and I returned one of my platies and one of my mollies (both males). The next week I added two Serpae tetras and two female platies. Then last week I added two more female platies and two female swordtails to help prevent further aggression. This brings my current total to 26 small fish. I hope I do not sound ignorant by asking this, but is all this commotion the likely culprit in the death of the my molly? My tank is 24 inches deep with 480 square inches of surface area. I have a Whisper 30-60 external power filter and I use a four inch air-stone in the back corner for increased aeration. Also, the tank is well planted. I am quite comfortable with my current population, and do not intend on adding any more, but do I have too many fish already? <You're near there> Also, I noticed that some of my new fish got their tail fins nipped, I am guessing by my Serpae tetras. I believe, however, that the fin nipping has stopped now that the tetras have grown accustomed to their new mates. Will the fins repair themselves, or, should I quarantine and medicate. I should add that the victims appear very happy and healthy. As always, thanks for putting up with my neurotic letters and thank you for all your advice. Sincerely, Walt <I wish we could "go back" and chat re your stocking plan... Know that the mix of fishes you list have quite different water quality desires, limitations... the mollies like some salt in their water... the tetras don't... and they like soft, acidic, warmer water than the platies, swords, mollies... IF all were in initially good health, the system kept stable, optimized there would not likely be problems.... but it being so new... some of them are sure to be "challenged"... even "cranky"... You obviously have a good mind and care a great deal... and all will work out fine... but do take a read on WWM, fishbase.org re specific (as in species) requirements, water chemistry... before any further purchases. Bob Fenner>
Ammonia in Fry Tank I have found your website to be very helpful. First I want to say that I am a proud owner of two mollies one a balloon black (female) and the other a orange (male). Two days ago I discovered 17 fry. I was so thrilled! I need help in deciding what to do. So far the adults have left to fry alone. No problems there. I have a 2.5 gallon tank and know that that is not enough room for all of them. I am wondering if I should take the adults out (to another 2.5 tank) and leave the fry to grow a bit bigger in the existing tank. I would like to possibly keep two at the most but want them to get bigger so I can determine the sex. I have spoken to the LFS and they will take a the rest from me. My levels are at ph. 7.8 nitrite .25 nitrate 5.0 and ammonia is at 4.0. temp is 78/80. I am a determined new aquarist. What is the safest thing to do in my situation? Thanks in advance. Vanessa I. Tucker <Water changes, and lots of them. 4.0 ammonia is deadly! And .25 nitrite is .25 too high and it's about to go higher. Check the pH of your tap water. If they are within 2 or 3 tenths then match temp, dechlorinate and change 50% right now. Wait a few hours and do it again. Then daily until ammonia and nitrite are at zero. Your problem is a lack of bio filtration, something that takes time to get established. Do move the adults out. The ammonia is from fish waste. The less fish, the less ammonia will be added to the tank. Read here on establishing FW bio filtration. http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm I hate to tell you to limit feeding the fry, food is very important to growing fish. But the more you feed the more waste will be produced. Just feed them twice a day and only enough that it's all eaten within a minute or two. Once the ammonia comes down you can up this to three or four small feedings a day. When you do the water changes use a gravel vac to get any uneaten food and old waste out of the system. You are going to have to continue with almost daily water changes for a month to six weeks. It will take about that long to get cycled. That link contains the most important information a new aquarist needs to have in order to keep their fish alive. And congrats on the births. 17 is a lot for a Molly. BTW they are not as bad as guppies and swordtails when it come to taking their young. As long as they do not get too hungry they generally leave them alone. But since you need to limit feeding, move the adults out. Don>
Aggressive Molly Hello! I have a question regarding the behavior of one of my mollies. I have 20 small community fish in a 50 gallon tank, among which are three pairs of differing mollies (black, sunburst, marbled). I just added a beautiful pair of Dalmatian mollies this afternoon to my display tank and I thought they would be fine considering there were no problems with my other mollies. However, one of my male sunburst mollies apparently has taken quite a dislike to both of the newcomers. Is it at least possible that his aggression will subside? <Yes> Is it just due to the fact that the Dalmatians are the "new kids on the block"? <Quite likely so> Or, should I be afraid for their lives and return them? Any help you could provide is appreciated! Thanks, Brody <Well, this is a good-sized system, doesn't sound overcrowded... If it's easy enough to do, I'd catch out the aggressive fish and let it "float" in a fish net, breeding trap, plastic colander... at the surface for a few days... sometimes this gives the other fish a rest, time to mix in with the new dynamic... Bob Fenner>