Excerpted from: Five Almost Perfect Fishes; Great fish for the community aquarium, except for one little thing… by Neale Monks    Black mollies, Poecilia hybrids  The good:            Hardy, friendly fish full of charm, they even eat algae! The bad:              Needs hard, alkaline water  Top of my list of almost perfect fish has to be the black molly. It’s a spectacular fish when kept in a planted tank, the velvety black making a bold contrast with the green leaves. Even with more brightly coloured fish, it holds its own, and makes a superb companion for things like fancy platies and swordtails. Few other freshwater fish are as jet black as these mollies, and most of them are nocturnal. Even cichlids keepers — usually spoiled for choice when it comes to colours — don’t have anything like the black molly; it’s a truly unique fish. Like people, the physically most attractive fish aren’t always the ones with the nicest personalities, but the black molly is every bit as friendly as it is beautiful. They won’t even harm livebearer fry. Despite their peaceable natures mollies are remarkably bold, and will settle into a new aquarium almost at once, making them great dither fish for encouraging more nervous fish like cichlids and gouramis to come out from their hiding places. It gets even better — mollies are very tolerant of nitrites, making them an excellent choice for maturing new tanks. Provided you don’t overfeed them, they’ll handle the entire filter maturation process without any problems; they are particularly valued in this regard by marine aquarists who use them instead of more delicate (and expensive) reef species. The icing on the cake is that mollies are fond of algae, and will happily graze on any green and thread algae in the aquarium. While certainly not in the same league as plecs or Siamese algae eaters (Crossocheilus siamensis), they do have an impact, and are especially good at cleaning delicate leaves where the larger, clumsier species can’t reach.  Really, the only shortcoming to the black molly is its need for hard, alkaline water. Of course, this isn’t really a problem for aquarists in the South East, and is in fact something of a plus. Unlike all those neons and dwarf cichlids that demand soft and acidic water to do well, here’s one fish that just loves standard issue London tap water. However, if you are keeping a soft water aquarium or have a planted tank with CO2 fertilisation, chances are the hardness and pH will be too low for the black molly. Ideally, this molly wants a pH of at least 7.5 and the water does need to be at least moderately hard. The addition of salt isn’t strictly necessary, but many people have found that it does help to keep mollies healthy and free of diseases like fungus and fin-rot; in this case, raising the specific gravity to around 1.002-1.005 will do the trick nicely and allow you to mix in a few brackish water fish as well.

My lovely mollies... sys., beh./comp.    8/5/09
Hi,
I have a 50 gallon aquarium that holds 2 male silver dollars, 8 zebra Danios (2 of which are Glo-fish), 3 cherry barbs, 2 glass cats, and 6 mollies - one silver male, one Lyretail silver female, one black male, one
black female, one Lyretail Dalmatian female, and one creamsicle female.
<Mollies don't usually do well in freshwater tanks, and if you must keep them in freshwater conditions, you need three things: a high pH around 7.5 to 8; a high hardness upwards of 15 degrees dH; and very clean water, 0 ammonia, 0 nitrite, and less than 20 mg/l nitrate.
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
Virtually all Molly problems come down to people insisting on keeping their Mollies in freshwater tanks -- despite what all the books say about them often needing slightly brackish water to do well. I cannot stress this point too strongly because I get Molly questions several times a week, and they often come down to this "mistake".>
Here's the problem, the silver male is very large compared to everyone else (about 4 inches) and is causing havoc.
<Normal. Keep adding females of his species (Poecilia sphenops, Poecilia mexicana, or whatever.) until he cannot bully just the one female. Adding floating plants helps a great deal too.>
He is chasing everyone - all the females and the male, and has even nipped up the tales of all the Lyretail girls. Now, the silver female seems to be losing her color and turning slightly gray. Can I assume this is due to the stress the silver male is causing?
<In part, yes, stress weakens the immune system allowing opportunistic infections to develop. On Mollies, these usually manifest themselves as Finrot, Fungus and/or Columnaris. These three diseases are very common when Mollies are kept in freshwater tanks, and even if your Mollies were healthy enough for a while, any negative pressure on them, such as bullying, could tip the balance in favour of these diseases. So, to recap, keep more than two females per male, and keep them in brackish water so these diseases are
less likely. It's really very simple, and explained repeatedly here and in aquarium books.>
He was acting fine when we first got him, but then the silver female that was in there with him died, and he starting chasing everyone. We went and bought the new females to try to calm him down, but it doesn't seem to have worked. He especially picks on the Dalmatian - I couldn't find her for 2 days, then she showed back up with her beautiful tail looking all torn up.
Now, if she gets near him, he immediately chases her away. He doesn't bother any of the other fish in the aquarium. Is there something I can do to calm him down?
<No. Male Mollies are aggressive. Evolution has worked to cause male livebearers to be aggressive and promiscuous because they are smaller than the males and have brighter colours, so are more vulnerable to predators.
So where a female can be picky because she'll live a year or two beyond maturity, a male only has a few months, if that, after sexually maturity, so he has to drive away rival males and inseminate as many females as he possibly can. You might not like the way evolution works, but there's nothing you can do about, and in the case of Mollies, this is the reality.
You could try adding two more males of his species, together with at least four more females of his species. The males might end up directing their energies towards each other some of the time, and if you had three of them, the one dominant male couldn't bully either of the other males exclusively.
Adding one male would be a nightmare, and the dominant male would likely batter the new one.>
I feel sorry for all the others - can you please make a suggestion as to what I can do? By the way, the water parameters seem to be fine and no other fish are showing any signs of health issues (with the exception of
the graying female and the now pitiful tails of the female Lyretails).
<The graying female likely has a bacterial infection, and you will probably need to treat.>
I greatly appreciate any advice you can offer, you are the best!
Jenna
<Cheers, Neale.>

Mollies, freshwater plants and fixing my mistakes 6/30/09
First, hello and thank you for such a wonderful site. I truly wish I had found this site long before I did.
<Thanks for the kind words.>
I especially wish I had found it before I went to the LFS and bought several "mistakes" that I now need to correct! (I am no longer certain that my LFS should be allowed to sell hairpins, much less living creatures
they know little to nothing about...)
<Hah!>
My young daughter asked for a fish tank for her birthday (she is three - and I *do* know that I will be doing all of the work!). Knowing that bigger is usually better and easier, I arm wrestled my dear husband into a 30 gallon tank. I have a 3 stage power filter running at 200 gph, heater (77 degrees or so), Cora-life light at 92w (about 3pwg) and Fluorite substrate. I ran the tank mechanically for a week, then added live plants (an assortment of South American easy-care plants: Egeria, Cabomba, Bacopa, tenellus, Ludwigia and Vallisneria).
<Some of those will definitely be easier to keep than others... but you'll soon spot the species that struggle!>
I let this run for a further two weeks.
<Sounds good.>
Here in south central PA we have very hard water (24GH) with a Ph around 7.6 or so. The KH is usually about 5 out of the tap. Thus, after carefully researching (or so I thought) I selected mollies for my daughter.
We hoped for easy care yet interesting fish with the possibility of some fry...
<Ideal water for Livebearers!>
We brought home one male and three female chocolate Sailfins as well as six pygmy Corys and two Oto-cats for algae. We carefully watched the ammonia rise to 20ppm then fall as the tank cycled. I never saw a significant nitrate or nitrite change. We *do* have a trivial amount of nitrite in our natural water - just enough for the dip test to register but no more.
Water changes at the moment (new tank) are on the order of 10% every two to three days. I was hoping this would fall back to a weekly chore once the tank was established.
<It will; especially once the plants get established, you should find the combination of plant growth and decent filtration rate should take care of ammonia and nitrite.>
Six days after bringing them home... you can guess. My carefully selected, slim, not-pregnant female mollies had fry. I had planned to allow nature to take care of this first batch but my daughter fell in love... now I have a hastily set up old 20gal tank with the fry and the original 30 gal as well. (hubby is not exactly pleased, he voted for a goldfish bowl...)
<Pff!>
We have lost all but two of the Corys but all water parameters seem fine. Surprisingly, the fry are doing well in their uncycled, undecorated tank (at least so far). I did move some of the water from the 30 gal into the
20 to help start the cycle and robbed the filter floss from the older tank for the newer one...
<Good.>
I came to your site and learned that the aquarium salt my LFS sold me is not the correct thing for the mollies. Worse, the Corys they assured me were fully compatible actually do not tolerate salt! (I have not yet determined what the Otos think about the tablespoon of aquarium salt per 5 gallons I added... probably not happy about it either!)
<They don't like salt, and they don't like warmth, so I wouldn't ever keep them with Mollies; Mollies certainly need warmth, and do prefer slightly saline conditions.>
So my questions are these:
1. My mollies need marine salt - I have purchased it. Can I give them enough salt to make them happy without killing my plants? If so, how much?
<Start with about half a level teaspoon (3 grammes) per litre of water in the bucket; that should produce a specific gravity of 1.001 at the 27 degrees C that Mollies prefer. See how things go. Your water is very hard, so salt is much less critical than otherwise.>
2. The tank already has aquarium salt in it. Do I just start adding the marine salt for water changes? Do I make a large water change and switch over? The tank is really only about 5 weeks old - not fully cycled yet.
<Just add the salt to each new bucket of water added during water changes.
Don't worry about changing the salinity all at once.>
3. Will the Corys and Otos do well? Do I need to get rid of them? Will I need another algae eater in their place?
<Hardy Corydoras will tolerate very low levels of salt as suggested above just fine; Otocinclus are more of a problem. Neither catfish appreciate warm water: both are best at around 23-24 C. Mollies are darn good
algae-eaters themselves, but alternatively I'd go with Florida Flagfish and Nerite snails, both of which will thrive in slightly saline conditions.
Amano Shrimps will also do well, as should Cherry Shrimps.>
4. Do the fry need the same salinity as well? (By the way, your FAQs on raising fry are fantastic! Even when read by a frantic mom at two am!)
<The fry need identical care to the adults.>
Thank you again for your time and care. I know I and my small daughter have already learned so much from your site. God bless!
Tricia in PA
<Cheers, Neale.>

Re: Mollies, freshwater plants and fixing my mistakes 6/30/09
Thank you so much for your fast reply.
<No problem.>
Am I to understand that the high GH with moderate KH is normal?
<Yes. General hardness plus carbonate hardness makes total hardness; the two things are not actually proportionally related to each other, though yes, water with a high General hardness tends to have a high Carbonate hardness too.>
(I had assumed that the two tended to be nearly the same... though I cannot be certain where I picked up that tidbit of information (or misinformation!)).
<Never mind!>
As I *do* have such hard water and moderately high Ph, can I get by permanently with the low SG of 1.001?
<Quite possibly. All depends really. If the water is clean, the nitrate is low, and the pH is stable, then yes, Mollies should do well within minimal, some would argue zero, salt.>
If so, I understand from another part of your site that my plants should do fine. This will be sufficient for the mollies?
<Hopefully.>
How can I measure my salinity? The hydrometer available at the LFS (yes, sadly, I do need to keep shopping there, there is no where else to go... but most of my equipment etc. all comes from online shopping anyway) will not read this low of a salinity (specific gravity). I believe, if I remember correctly, that the lowest marked point is 1.015 - far too high for my purposes.
<A basic glass hydrometer calibrated for 25 degrees C should work fine; these cost $5. If you look on my web page, you'll see a little Mac/Windows application that helps you see how salinity, specific gravity, and
temperature are related. Http://homepage.mac.com/nmonks/Programs/brackcalc.html
You're aiming for about 3-4 grammes of marine salt mix per litre.>
Any further suggestions? I really do wish to be a good "fish mother".
Especially as this is meant to be a teaching opportunity for my daughter as well.
<Indeed.>
As for the other fishes, I will begin working on another situation for them. And, of course, beginning a search for the fish you suggested for algae control (Florida flagfish - I am just beginning to research these
now. I have been waging a war on snails in the tank - perhaps I should just let them be?).
<Snail populations grow proportionally with the food in the tank: uneaten fish food, fish faeces, and dead plants. Keeping the tank clean, siphoning out waste (a turkey baster is a great tool for spot cleaning!) and removing dead plant material goes a long way to "starving" snails. The less food, the fewer the snails. Add a few Clea helena if you want a good, safe snail predator.>
Thank you again for your suggestions. I am very grateful. It is so rare to find a website with real, clear information and kind folks who take the time to disseminate it. Thank you again!
<My pleasure. Cheers, Neale.>

Mollies & more 3/27/2009
Hi WWM team. Your site has helped us but I have some Q & comments.
<Fire away!>
1. Why do you not advise adding limestone for mollies instead of salt?
<We (I) recommend neither. I specifically recommend marine salt mix, which takes care of the carbonate hardness, pH and salinity issues all at the same time! Limestone can be added to aquaria, but it raises carbonate hardness by an unpredictable degree. Do you know how many pounds of rock to add per gallon of water to get a hardness of 10-20 degrees dH, a carbonate hardness of 7+ degrees KH, and a pH steadily holding at around 7.5? Nor do I. Moreover, because limestone gets covered in algae and bacteria over time, it loses its buffering capacity. (Think of how the candy shell of an M&M prevents the chocolate from melting in your hand; it's the same thing.)  So unless you take all that rock out every couple of weeks and clean it, over time, it'll benefit your Mollies less and less. Crushed limestone and crushed coral in an undergravel filter are better in the sense of having much of surface area in contact with the water, but they still lose their buffering capacity over time. The addition of marine salt mix is therefore a cheap, easy way to get perfect Molly water every single time! 5-6 grammes per litre does the trick nicely. It's a no-brainer.>
2. Why doesn't Bob like Melafix?
<Because Melafix doesn't work reliably. We give advice that we know works, or at least, works most of the time. Melafix (at best) works *sometimes* on mild infections. You'll note that neither MDs nor veterinarians recommend tea-tree oil for treating fungal and bacterial infections. Neither do we.>
3. I read a Q from an experienced fish keeper about a new tank where the water went white and was too warm and the fish went crazy. She had used nice established water from her main tank. We had the same thing. The clues are temp too high, the 'whiteness', and bubbles forming on the glass as well as the fish going crazy and 'gasping'.
<Ah, yes, sometimes water can go "white" under these circumstances. What you're describing is oxygen coming out of solution when water warms up.  It's the same reason why a glass of cold water put by your bed at night will have bubbles around the glass by the morning. Water holds more oxygen when cold than when hot, so as temperature goes up, oxygen dissolves out.  Most of the gas bubbles away into the atmosphere, but some will adhere to imperfections on the glass, which is what you see. Now, this is absolutely not the reason most tanks go cloudy. Usually when aquaria have cloudy water
it's a silt issue or a bloom of either bacteria or algae.>
She did not mention the bubbles. All are signs of 'flat' or semi-boiled water such as might be seen in water from the hot-tap when put into a drinking glass. Is this not well known?
<It happens, but to be honest the temperature variation in most aquaria should be trivially small because of the heater. Sure, if you add fresh cold water and then add the heater and warm it up, you'll see bubbles on the glass. But an established tank at the usual 25 degrees C won't experience this (unless the water has become supersaturated with oxygen at some point in the filtration/circulation cycle).>
I was surprised she had not seen this in her years working in pet shops and WWM put it down to 'new tank syndrome' with no further explanation and told her to clean the tank with bleach and the necessary follow up. Good advice to ensure all foulness was gone, however the new aerated water is the real solution.
4. I am confused as to the best way to kill a fish if needed as WWM guys seem to differ on this.
<This is a part of the hobby with much misinformation, and certainly things I considered humane twenty years ago are now known to be anything but! So for example the use of ice is now considered to be stressful to the fish and not recommended. Articles on WWM are anything up to ten years old, perhaps more, so in some cases advice offered in good faith then would now be considered inappropriate. Do read here:
http://www.wetwebmedia.com/euthanasia.htm
The article is based on current scientific and veterinarian practise, rather than hobby anecdote.>
Keep up the good work. S
<Thanks. Cheers, Neale.>

Re: mollies & more (Euthanasia; cloudy water; Melafix) 3/27/2009
Great answers! Thanks Neale. I should have specified I meant marine salt, I am txt-ing and got lazy.
<No problems.>
Apparently the amount of limestone rock doesn't matter as it will only raise the carbonate hardness etc. to a specific level and only if they drop will more release.
<Ah, yes, limestone will not raise the pH above a certain level, but if you don't have enough, it won't dissolve fast enough to compensate for background acidification or the addition of soft water during water changes. So there is an optimal level balancing quantity against efficacy.>
Sorry, I didn't do the research, my partner did prompted by the fact that mollies are kept in fresh, brackish and salt aquaria, he is also the one with the scientific mind and he could explain more scientifically. Aquaria mollies apparently are descended predominately from limestone caves from Mexico (if memory serves, again his research) although found elsewhere including mangrove swamps.
<There have been numerous theories about where the domesticated Molly comes from, none of them completely convincing. The flip side is that feral Mollies -- that is, aquarium Mollies released into the wild -- have become established in all kinds of habitats, including the sea (Gulf of Thailand) and freshwater streams ( Australia, California, etc.). So in the wild at least, where water quality is much better than in aquaria, salinity doesn't seem to matter much. It's in the aquarium where Mollies become delicate, and where the addition of salt is usually recommended (though not all experts agree on this, I accept).>
We have a molly only tank so we have the luxury of being able to create conditions specific to them. There are a couple of benefits limestone offers mollies that m/salt does not or in much reduced amounts such as magnesium.(I should have done the research myself!)
<Marine salt mix should raise carbonate and general hardness substantially, and I can't see precisely what limestone would do differently, or better.>
As much as I think my man has a brilliant mind I'm not adverse to another opinion or two.
<Wise.>
The other reasoning for limestone rather then salt was maintaining consistency of water state (I note your 'unpredictable' comment) as they can adjust to a water state but don't like to have adjust their internal biological state all the time for external changes (owner stuff ups-the same reason for choosing fish that suit local water ph rather then using ph up/down). Limestone is cheap as chips here too, even compared with m/salt. My mollies are far more resilient with it. I will be discussing your advise in the morning though.
<Ultimately the only way to settle this is experiment. Simply experiencing one set of conditions and assuming it is the ideal can be misleading. If you had three tanks, one with limestone, one with marine salt mix, and one with neither, and then ran all three tanks for six months, then we'd perhaps have grounds for a scientific research paper! As it is, while your approach may well work extremely well, it's difficult to know how to generalize that outwards to Molly keeping generally.>
As for tea tree there are many different types of plant that fall under this term and the one used for Melafix is a paperbark that grows in mangrove swamps and it is different to the tea tree commonly prescribed by both MDs and vets here in Australia.
<It's Melafix that Bob and I tend to rail against. I've not used Melafix -- I admit -- but I've received a lot of mail here at WWM from aquarists who have treated sick fish with Melafix but their fish have failed to recover.  I'm open minded to its value as, say, a preventative, but it wouldn't be my "drug of choice".>
It certainly helped our Betta who came from the shop with curls and a fungus (live and learn).
<Cool.>
Again, here in Oz ordinary cold tap water is regularly 'flat' straight from the tap due to our high temps (today was a cozy 36C coming into autumn) a mistake we only made once.
<Here in England, the water is a good deal chillier than that out of the tap! When I use rainwater, it's often barely above freezing, and you have to be careful adding small amounts of that to tropical tanks or the fish go rather doolally for a while.>
Thanks for the link, sadly we made a bad choice of a pair of red fin sharks when starting out based on pet shop advise.
<Oh. There are few "sharks" that are genuinely good community fish, and unless there are facts to the contrary, I tend to recommend casual aquarists against them in favour of things like the smaller Garra species or the Siamese Algae Eater.>
You have as usual been very helpful. Thanks again.
<Most welcome. Cheers, Neale.>

Planted or brackish for mollies...   3/9/09
I love your site! I could read on for days!
Anyway, I have a 12 gallon brackish tank with 4 mollies and 2 guppies.
Nitrite 0
nitrate around 20 give or take.
PH 6.7
fish are healthy
Twice weekly 20% water changes
I am looking into creating my tank into a planted tank but I have some questions...
Will my mollies be fine in a planted tank rather thank a brackish tank?
Is my 13 watt bulb enough for some easy plants? (Java fern, tape grass, moneywort, dwarf Anubias)
If I do decide to plant what is the best thing to do with my fish while the tank cycles? (I have a molly friend that lives near and a couple teeny tanks-1 gallon and 2 gallon...)
I am worried that the tank will look murky and "lettuce bowl" like - not like some of the really nice ones I have seen. Is there a way to prevent that?
How can I prevent snails and or snail eggs from getting into my tank? I have heard "picking at it" "Shaking eggs off" "dips" "water treatment" Which is best?
Thanks a bunch!
Hannah
<Hello Hannah, and thanks for the kind words. The short answer is there is nothing to stop you having a planted brackish water aquarium. Lots of aquarium plants naturally come from brackish waters and if all else is equal they will thrive under such conditions in an aquarium. I keep a list of some of the best species on my Brackish FAQ pages, so stop by and take a peek:
http://homepage.mac.com/nmonks/Projects/FAQ/2d.html
That said, at barely 1 watt per gallon, you're going to be hard pressed getting any plants to grow in your aquarium. Most plants need around twice that amount of light to do well. Java moss, Java fern, Anubias, and perhaps some of the hardier Cryptocoryne species are the best choices. Sometimes Vallisneria adapts to low-light conditions, but it's hit and miss.
Moneywort is a non-starter; it needs a lot of light. I'd suggest sticking with epiphytic plants (Java moss/fern, Anubias) for two reasons. Firstly, they're good choices, but secondly, they don't need a fancy substrate. They get their nutrients from the water, unlike plants with roots. This will mean you won't need to fill the bottom few inches of the tank with gravel and aquatic soil, leaving more room for the fish. As for snails. I don't see them as a problem. Tanks with snail plagues usually have other, more serious problems. Snails convert uneaten food and organic waste into baby snails. If the tank is basically clean, there's little for the snails to eat, and they breed slowly, more or less at the same rate as they die or get eaten by other fish. That said, I know some people have snail phobias.
In this case, the best approach is to clean plants before they are put in the tank. You can buy snail-killing potions over the counter, and all you do is make up a bucket of stuff, stick the plants in there for a certain length of time, and then remove the plants knowing that they are snail-free.
http://www.wetwebmedia.com/plantedtkssubwebindex/snailsags.htm
Never, ever add snail-killing potions to an aquarium, even if the package says the chemicals are safe for fish. While the chemicals themselves may be harmless, lots of dead snails all rotting simultaneously will do nothing to improve water quality!
Cheers, Neale.>

Poecilia/Mollienesia (health, water quality)  2/10/09
Hi, my name is mike.
<Hello Mike,>
I have a white balloon Molly that is sick. My water parameters are: pH is 7.2, Ammonia is 0 ppm, Nitrate is 5.0 ppm, Nitrite is 0.25 ppm. The tank is a 20 gal. freshwater with no salt at all.
<Well, there's the first problem. The tank is too small and has the wrong water for Mollies. Mollies need big tanks because they are sensitive to poor water quality. You have poor water; ergo, your Mollies will get sick.
In fact the nitrite level is way too high for any aquarium, and you need to URGENTLY review feeding, stocking, and filtration. Your tank will never work correctly with 0.25 mg/l nitrite: fish will constantly be getting sick. As you mention salt, you probably realise Mollies appreciate salty water. It isn't essential in a well-run, big, clean tank with hard,
alkaline water -- but your aquarium is none of those things. The addition of marine salt mix (not tonic/aquarium salt!) will raise the pH, hardness, and salinity to levels that favour Mollies, and indeed many other livebearers as well.>
The tank is shared with two Goldfish, One Dwarf Gourami, One Angel fish, two Platy's and two Cory's.
<Platies are good companions for Mollies, Goldfish potentially so, but the others shouldn't be here because they don't really like brackish water. Up to around 3 g/l, both Platies and Goldfish will do fine.>
None of the fish nip at each other and all look well after almost three months together (after cycling for a month) The Molly, just one day ago, has been laying on the bottom of the tank breathing very shallow, not eating and not passing waste, listing and swimming nose down on occasion and backwards sometimes, but every once and awhile will swim just fine and go to the surface (but very rare) the fish looks like it's paralyzed to a degree.
<Shimmies or equivalent... dying...>
The Molly has Been in a separate tank for about 20 hours now, filled with some water from the original tank and some new water, both tanks have identical water and the filters are the same with an air stone working off the same air pump as in the larger tank. I've looked through most of the site about Mollies and some about Angel fish, and found similar but not the same symptoms. I feel horrible for the poor thing and was wondering if there is anything at all I could do to help it. Thank you in advance for the help trying to make the fish better.
<Angels and Mollies are not compatible. Review the needs of Mollies, set up a tank as required, and enjoy better success.
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
Cheers, Neale.>

Re: Poecilia/Mollienesia (health, water quality)   2/11/09
Thank you so much for your reply and the advice you gave, but unfortunately the molly didn't make it. I feel horrible that my incompetence killed an amazing little fish like that.
<Not incompetence, merely lack of knowledge. Do read a fish encyclopaedia before spending any money: it's pretty widely known Mollies like a little marine salt mix in their water, and while not essential, it does make them much easier to keep. Because of this requirement, I recommend keeping them with species that tolerate or enjoy a little salt too, such as Platies, Swordtails, or Guppies. Indeed, most any livebearer will do well.
Australian Rainbowfish and many Killifish also fall into the salt-tolerant category, so it's really not that big of a deal. A box of Instant Ocean marine salt mix will last months at the required dosage, so it's a lot cheaper than [a] buying new fish and [b] buying fish medications.>
I bought a larger tank yesterday afternoon (along with a canister filter and new sandy substrate) and look forward to creating a much better environment for the fish that have me and my family glued to the tank for hours at a time (well maybe just me most of the time)
<Ah, a tank with a sandy substrate opens up LOTS of options, such as Gobies. Look up Knight Gobies (Stigmatogobius sadanundio) and Violet Gobies (Gobioides broussonnetii) as examples.
http://www.wetwebmedia.com/brackishsubwebindex/knightgobyfaqs.htm
http://www.wetwebmedia.com/brackishsubwebindex/bracgobioids.htm
They need brackish water, and positively THRIVE alongside Mollies at, say, SG 1.005 (about 9 grammes salt mix per litre). Violet Gobies are big, ugly but really funky animals that make great pets. Faces only a mother could
love! Watching them filter feeding on live brine shrimp is one of the most fun things in the hobby. They're gentle giants, and won't even eat livebearer fry if properly fed on worms, crustaceans and the odd algae wafer.>
I do thank you for the advice and all the priceless information you guys diligently dole out about such a great hobby and hope that one day I will be able to help someone with as well.
<We're happy to help.>
Thanks so much
Mike
<Cheers, Neale.>

Liberty Mollies, sys.    2/2/09 We have two female liberty mollies. When we purchased them we were told that they were freshwater mollies. We have learned since then that most mollies prefer brackish water or salt water. My question: Is it true that liberty mollies will do well in fresh water? Thanks for your time! Debbie <Debbie, The Liberty Molly (Poecilia salvatoris) is a true freshwater species -- but then so are ordinary Mollies like Sailfin Mollies and Shortfin Mollies. The problem is that what fish need best in aquaria isn't necessarily what they experience in the wild. Slightly complicating matters is that for many years the Liberty Molly was not recognised as a distinct species, and was assumed to be a mere variety of Poecilia sphenops, so aquarium books usually say very little about this species. Now, having said all this, like most Mollies the key things are probably water quality and water chemistry stability. Very hard water (certainly upwards of 15 degrees dH) with a stable pH somewhere between 7.5 and 8 is what's required. Water quality must be excellent, with zero ammonia and nitrite. Nitrate is also an issue, and I'm increasingly of the opinion that what makes or breaks Mollies in freshwater tanks is not the lack of salt as such, but dangerous levels of nitrate. Sodium chloride reduces the toxicity of nitrate, and so in salted water Mollies are not sensitive to high levels of nitrate. What's a high level of nitrate? Probably anything around 20 mg/l or more, if nitrate sensitivity among cichlids and marine fish is anything to go by. Liberty Mollies are very active, apparently fast-water fish, so water current and oxygen are likely to be important. My hunch is that if you got all these factors right, you might not need to add any salt at all. On the other hand, if things weren't quite right and your Liberty Mollies were prone to fungal infections or Finrot, then the addition of a small amount of marine salt mix would stabilise the pH and reduce the toxicity of the nitrate. You don't need much for this effect; around 3 grammes per litre should be ample. At that level, you could easily maintain them alongside other livebearers. Swordtails for example come from a very similar habitat. I'd avoid mixing them with any Poecilia species (Mollies or Guppies) because of the risk of hybridisation. What a tragedy it would be if you lost out on producing good quality offspring from this beautiful and rarely maintained species! Please do breed them carefully, and share the offspring with other fishkeepers. Cheers, Neale.> Re: Liberty Mollies (Environment; salt)   2/4/09 Thank you so much for the valuable information. Here is a picture of one of our mollies! <Happy to help, and thanks for the picture. Looks like a nice, healthy female. Both sexes will colour up nicely as they mature, but take care to include algae and small crustaceans (such as daphnia or brine shrimp) in their diet, as these are keys to bright colours in fish. Cheers, Neale.>

Hello, brackish salinity question 01/13/09
Hello again,
After much consideration, I have decided to change my tank to brackish for my mollies. Most websites I go to say 1/4 cup per gallon. is this ok?
Thanks!
<Hello Rachel. The ideal salinity for Mollies is between 6 and 9 grammes per litre of water (about 0.8 - 1.2 oz per US gallon). The resulting specific gravity is 1.003 to 1.005. This is low enough that your filter bacteria will quickly adapt without fuss, but salty enough the Mollies will be palpably healthier and hardier. While you are free to find out how many grammes (or ounces) of your particular marine salt mix fit into a cup, once you've made up your salty water, you should use a hydrometer to check the specific gravity. A basic floating glass model costs about $5, while plastic swing-arm models are a bit more expensive. Why check the specific gravity? Because once a box of salt is opened it absorbs water from the atmosphere. Over the weeks, each teaspoon or cup or gramme or ounce actually ends up being partly water, so that going by those measurements alone you'll be underestimating the amount of salt added to each bucket of water. The variation isn't too serious if you keep the bag of salt tightly closed inside an airtight container, but it's worth checking nonetheless.
You can also use your hydrometer to check the specific gravity of the aquarium itself. During summer especially, evaporation will cause salinity to rise as water evaporates away. The Mollies won't care much, but any plants in the tank might, and the filter bacteria certainly don't like dramatic changes in salinity. Cheers, Neale.>

Caring for mollies  12/30/08
First, let me say that your site is wonderfully helpful. I am brand new to caring for fish and have spent hours upon hours on the internet looking for help, and this is the first truly helpful site I have found.
<Thanks for the kind words.>
Two weeks ago, I inherited a 30 gallon aquarium with 23 or so small fish. 3 are male black mollies, about 20 are Dalmatian mollies (more females than males, although it's difficult to count them), and two small fish that I can't seem to identify. I have searched the internet and asked at the local pet store, but no one seems to know. They are orange, about an inch long, and they have a few very thin white stripes running the length of their bodies, and round bellies. Their fins are almost transparent. (Also--one of the Dalmatians is a baby, not quite 3 weeks old).
<Quite possibly "balloon" Mollies.>
The person who had the fish before me did not take proper care of them. The filter had never been changed (at least 6 months), the water was rarely changed, and the fish were being seriously overfed. They died regularly, and they were regularly replaced with new fish. I was told that only two (the orange ones) are "originals," and that there have been two successful pregnancies. Most of the first fry survived (12 fish, I think), and only one from the second. I don't know if that information makes a difference....
<Oh dear. Do start here:
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
Maintenance of Mollies is not difficult, but frequently "done wrong".>
I am doing my best to keep up with the cleaning--thankfully, I have not
lost any fish. I took some water to the local pet store and a "fish expert" there tested the water and told me everything looked good, and that I should change 10% of the water once a month
<Too little... 25% weekly more sensible. The "10% per month" is how the hobby was done 25 years ago. We've moved on... and the fish live longer for it.>
and add bacteria like StressZyme
<Redundant... he's trying to sell you stuff... Once the bacteria in the filter are established, they'll last the lifetime of the tank. No need to add more.>
and a handful of salt with each water change.
<A "handful"? Pretty meaningless. Instead, go for 5-6 grammes of marine salt mix per litre.>
She also showed me how to change the filter (which was disgusting, as it had never been changed before).
<Every couple months, give the filter media a rinse in a bucket of water taken from the tank.>
I have been keeping up with everything as instructed. The male black mollies were very aggressive,
<Yes, male Mollies are...>
and the pet store suggested that I get 3 female black mollies for them to mate with. I was relieved when the aggression completely stopped, in less than a day. (So now there are, I believe, 26 fish).
<OK.>
Also: the water temperature fluctuates between 76 and 78 degrees.
<No big deal.>
The heater is on as high as it goes. There are also some live plants, one fake plant, and two decorative items, all of which the fish LOVE. I was told the rocks weigh about 40 pounds, but I am not sure if that is correct.
<Oh.>
The day before yesterday, the fish started acting sluggish. They weren't really swimming much (other than two of the males who are constantly trying to mate). Most of them have not been interested in food, either. I am extremely careful not to overfeed them. I had changed the water about a week and a half before, but I thought something might be wrong with it. I tested it today, and the nitrate and nitrite levels were both high ("unsafe" according to my test strip comparison chart). I followed the directions for adding salt and bacteria, and I changed about 25% of the water according to what I read on this site. In 5-10 minutes, the fish completely perked up! As I had cleaned out the debris from all the food they hadn't eaten, I fed them again and they ate with appetite. I was happy to see this.
<Mollies are highly sensitive to Nitrate, and in freshwater tanks tend to get sick at nitrate levels above 20 mg/l. Nitrite and ammonia are both toxic to them, but in brackish and marine conditions they tend to be much hardier. Changing water reduces concentrations of all three chemicals, hence the fish "perk up". Marine salt mix contains sodium chloride, and to some degree this detoxifies these chemicals as well. Plain aquarium salt (the kind not used in marine tanks) does this too, but it doesn't have the second benefit of regulating water chemistry by raising the carbonate hardness, hence my advice to opt for marine salt mix, and not to waste your time with aquarium (tonic) salt.>
But now, several hours later, I tested the water again just to make sure it's okay. The levels seem to have gotten worse. This is what the strip reads:
Nitrate: between 80 and 160
<Extremely bad.>
Nitrite: between 1.0 and 3.0
<Dangerous.>
Hardness: 150
Alkalinity: around 80
pH: between 7.8 and 8.4
<pH variation is too much; marine salt mix at the dose described above will fix this.>
Another thing I have noticed, in the past week or so, they have been spending a lot of time near the surface. They splash a lot, which is something they did not do before. The past couple days, they would crowd together up at the top of the aquarium, barely moving, until one would "jerk" and the others would literally jump to get away. Since I changed the water today, they haven't done this at all, but there is still a good deal of splashing.
<The water quality is extremely poor. The tank may be overstocked, but is certainly under-filtered and not receiving enough water changes. Unless there is zero ammonia/nitrite, and sub-50 mg/l levels of nitrate, your water isn't safe.>
What should I do? Forgive me if the answers are elsewhere on your site.
<They are; but do start at the Mollies article listed above.>
I have tried to read it thoroughly, but there is terminology I do not understand. I am so completely new to this! For now, the fish seem okay--worlds better than before. They are swimming around, and about half of them are pecking at the gravel, looking for food. I am just concerned about the results of the water test. Any help you can offer I really appreciate.
Thank you!
<Most welcome.>
Amelia
<Cheers, Neale.>

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.>

Questions (Mollies; community tanks; water chemistry)   10/21/08
Hello, hope things are going well for you today. I have a couple of questions, please. First, when purchasing swords and/or mollies I know it is best to have several female to one male, but if you have say 2 species of mollies, is it OK to get 1 male of each species or do you just get 1 male molly period?
<Males of all livebearer species fight with each other. It's your call whether you keep a single male or a dozen males where no one fish can become dominant. But twos or threes rarely work, with one male becoming dominant and the others being terrorised. Personally, I like my fish to be happy, and would ALWAYS recommend keeping livebearers in groups of one male to two or more females, and multiples thereof. If that doesn't appeal because you want "one of everything in the shop", then don't keep livebearers.>
Also, please tell me the ratio of male to female for rainbowfish and how to tell the difference.
<With rainbowfish you can't normally sex juveniles of most species. There are exceptions like Glossolepis incisus. In any event, you want equal numbers of both to minimise bullying and ensure the males colour up once they mature. So buy six, three of each sex if possible.>
Lastly, do you feel mollies are fairly hardy fish to keep for beginners?
<Absolutely not. Mollies are extremely difficult to keep in freshwater and would never, EVER recommend them to beginners with a freshwater tank. At best, 50% of them seem to get sick or die when kept in freshwater. Please review our Molly FAQs for some of the horror stories. If you don't want to keep a brackish water community, don't keep Mollies. There are plenty of other large livebearers. Swordtails look great, though the males are even more aggressive. Limia nigrofasciata is a lovely fish with a "sail fin" and the males get a humped back that makes them look quite funky.>
I know they require a higher PH than some fish. Could I keep them with rainbowfish and Corys and a couple of Kribs, and if so, what would you recommend for the ph to be?
<Rainbowfish, Kribs and Mollies could all be kept in a slightly brackish water aquarium at SG 1.003, pH 7.5 or so. The only problem is that when the Kribs breed (which they will!) you will get mostly male fry because sex is determined by pH. If you were going brackish, I'd actually recommend Etroplus maculatus as a colourful, hardy cichlid for the community tank.>
I know they sell stuff to make it neutral.
<Unless you're an expert fishkeeper, don't even think about altering water chemistry. The fact you've asked about pH and not hardness suggests to me you don't understand the topic. Realise this: pH is not important, hardness is. We measure pH because it's easy, not because it's important. Beginners often mistake pH for something fish care about, but they don't. Most fish can tolerate a wide range of pH values without complaint. But they are often much more specific about hardness.
http://www.wetwebmedia.com/FWSubWebIndex/fwh2oquality.htm
Much better to find out whether you have hard or soft water, and then select your fish accordingly.>
Thanks so much.
James
<Cheers, Neale.>

Re: Questions (Mollies; community tanks; water chemistry) 10/21/08
Hi Neale,
<James,>
So as far as livebearers go, if I have 2 different types, say swords and platies I can get a male for each type as long as I have several females of the same type, i.e. 1 male sword-3females and 1 male platty-3 females?
<Correct.>
Not just 1 male period for the whole group?
<Like one male Swordtail and two female Platies? That would work, too.>
Also if I have 3 different species of swords
<All the traded Swordtails are a single species, just different varieties. Like Dobermans and Poodles are all dogs, however different they look.>
would I be able to get 1 male of each species with several females of each or just 1 male sword period?
<So long as you have one Xiphophorus helleri male and multiple Xiphophorus helleri females, it doesn't matter if they're Red Swordtails, Green Swordtails or whatever.>
Do I have to have brackish water for rainbowfish and Kribs?
<Nope; both these fish prefer neutral, moderately hard water. They just happen to tolerate slightly brackish water.>
If so I will disregard them because I want to keep cories and I have read that since they are scaleless they cannot tolerate salt.
<Corydoras will tolerate small amounts of salt (SG 1.001-1.002) just fine according to the likes of Dave Sands, noted catfish expert. That said, for the brackish water aquarium I'd always recommend the salt-tolerant catfishes such as Hoplosternum littorale. The "absence of scales" is irrelevant, since lots of marine fish, like eels and sharks and puffers have no scales.>
When picking out a pair of Kribs do I have to get 1 male and 1 female or will 2 of the same sex be OK?
<Both males and females can be aggressive. Therefore it's best to get a boy and girl, and let them pair off. Singletons are fine, by the way, and a group of females wouldn't be a bad idea. Since the girls are prettier than the boys, there's no loss. I keep a female Pelvicachromis taeniatus in one of my community tanks.>
And do you feel Kribs are ok for beginners or should I get another kind of cichlid?
<They're one of the best "beginner" cichlids. There are others though; do read around. Cheers, Neale.>
Do you recommend putting aquarium salt in a fw tank?
<Not unless you're keeping brackish water fish, no. Cheers, Neale.>
So if I get 2 or 3 females of the Kribs that would be OK?
<Should be just fine. There might be some scuffles over hiding places, but nothing too serious. Introduce them all at the same time to minimise the chances of any one fish becoming a bully. Obviously they won't breed, but that's no loss; breeding Kribs is just too easy, and most pet stores will reach saturation point of baby Kribs before too long! Cheers, Neale.>
Please tell me the best way to dechlorinate my tap water before making water changes in fw tank. I read an article on your site but was kind of confused.
<In what way were you confused? Seems pretty obvious to me: add dechlorinator as instructed on the bottle. If your water has chloramine in it (your water supply can tell you this) be sure and use a dechlorinator that treats chloramine (most do these days, so it's not really a big deal).>
Also, what type of resin or carbon is best for chemical filtration?
<In freshwater tanks, chemical media are largely redundant, except in a few exceptional circumstances. For most community tanks it's best to concentrate on biological and mechanical filtration. Cheers, Neale.>

Re: Questions (Mollies; community tanks; water chemistry) 10/22/08
Hello Neale,
<James,>
Please excuse me for all of the questions. I was not trying to be rude. I suffer form OCD and when I get going on a particular thing it is hard to stop.
<Oh, okay.>
Not making excuses. Just letting you know I really am one of the most polite people around. Have a good day!!
James
<No harm done. Have a good day yourself! Cheers, Neale.>

Balloon Mollies - One of 'em not mixing (Behaviour; environment?)   10/17/08
Hi,
<Hello,>
We've recently bought three balloon mollies (One male, two female). The male and one of the females are instantly pals, always shadowing each other and playing.
<No, they're not playing. The male is trying to mate, and more than likely the female is trying not to! It's always dangerous to anthropomorphise when talking about animal behaviour. Most animals I know get very offended when I assume they think like humans!>
They were quick to begin exploring the tank after being introduced. The other female however, does not join them. She seems to spend a lot of time against one side of the tank. She's not up at the surface, nor hiding from sight. She just keeps going up and down as if she's searching for a way out. They are the first 3 fish in a 30 gallon tank. The water properties are good (7.5ph, 0.25ppm nitrate current, 81 degrees F)
<Hmm... do you really mean "0.25 ppm nitrate"? That's very low, and not many consumer-grade test kits register such tiny amounts. If that's 0.25 ppm nitrite (note the "I" in there, as opposed to the "a" in nitrate) then we have a whole different ball game. Mollies are incredibly sensitive to nitrite, particularly if (unwisely) you have opted to keep them in freshwater conditions (which, frankly, hardly ever works out well). If you have a nitrite level that is detectable, then you have too much, and Mollies respond by getting sick, and then dying. Consider them "miner's canaries" if you like. If this is a new aquarium, I'd heartily recommend switching to slightly brackish conditions by adding marine salt mix (Instant Ocean, Reef Crystals, etc.) at a dose of, say, 4-6 grammes per litre. Sodium chloride has a useful property of undoing some of the damage caused by ammonia and nitrite, and marine salt mix also contains other minerals that buffer the pH and hardness. Net result, Mollies thrive instead of survive. This low dose won't harm your filter. Since Balloon Mollies shouldn't be mixed with any other type of fish, the fact you're adding salt isn't an issue in terms of tankmates. Problem solved.>
Now, she is white and the other two are black, can that be an issue? (the two black ones seem to gently 'recruit' her away from the side of the tank from time to time)
<Nope; all the same species, or likely hybrid.>
Also, she is significantly more plump then the other two. If she's pregnant, will she be anti-social?
<Nope.>
Thank you in advance,
Nick
<Cheers, Neale.>

Re: Balloon Mollies - One of 'em not mixing (Behaviour; environment?)   10/19/08
Hi
Thanks for the prompt reply.
<Most welcome.>
First off, I did mean 0.25ppm Nitr[I]te. I'll admit, we only allowed the new tank about a week and a half of cycling before getting the mollies. We figured three of them in a 30 gallon would help speed the cycling process (with daily partial water changes until it settled).
<Then that's why your Mollies aren't well. Case closed. Mollies just don't tolerate nitrite or ammonia well, at least not in freshwater conditions.>
As far as the salt goes, we have very slightly brackish water (about half the recommended treatment - so a tablespoon per 10 gallons) as we did intend for this to be a community tank.
<This isn't "slightly brackish" anything. Slightly brackish is around SG 1.003-1.005, 6-9 grammes per litre. Six grammes of salt is about one level teaspoon, and one US gallon is 3.75 litres. So if my math is correct, SG 1.003 is about 22.5 grammes of marine salt mix per US gallon, or just under four teaspoons of marine salt mix per US gallon. Ten US gallons would therefore need 4 x 10 teaspoons = 40 teaspoons, and 40/3 = 13.3 tablespoons of marine salt mix. Your dose of salt is quite obviously not nearly enough to make a difference. I just can't stress strongly enough how important it is for Mollies to be kept -- long term -- in brackish water.>
(plans were for two angels, three mollies and 5 or 6 medium tetras/Danios/somethin'rathers)
<Forget it. Mollies don't work with these fish. Instead look for other brackish water (or at least salt tolerant) tankmates. Very many options, including Guppies, Halfbeaks, Limia, gobies, sleepers, certain cichlids, even certain catfish. Plenty on brackish water species at WWM.>
However!... The white molly I wrote to you about gave birth and now she is social with the other two. Shortly thereafter, the black female went into hiding on the gravel, under a log and later that day, she started birthing too. I'm sure a number of 'em got eaten but we have spotted and netted 18 fry in all. We don't have a separate tank for 'em so I'm keeping them in the breeder trap for now.
<Cool.>
I guess I'll add the bit more salt and just look forward to watching some of these little ones grow up instead of getting other fish. lol Will they be okay in the breeder trap until they are large enough to swim free with the adults?
<The babies will be fine with their parents once about 1.5 cm long, which should only take 6 weeks or so.>
Nick
<Cheers, Neale.>

I have a new white Molly in my aquarium.  9/25/08
<Freshwater or brackish? Do review the needs of this horribly misunderstood species.>
It has been in the tank for a few days and seems to continually slide up and down one side of the glass in the tank. The ammonia and nitrite levels are at 0 and under 4mg/l respectively nitrates at zero.
<Nitrites are FAR too high. Mollies are extremely intolerant of nitrite. If this is a freshwater tank, ammonia and nitrite should both be zero. In brackish to marine conditions (SG 1.003 upwards) Mollies will tolerate a bit more nitrite for a short while, but certainly you shouldn't be allowing this level to go above 0.5 mg/l. Be under no illusions on this: Mollies cannot be used to cycle freshwater tanks. Their mortality record under such conditions is incredibly high.>
I was wondering if it had something to do with the reflection in the glass. The tank is roughly 60l or 15 US gallons.
<Too small for Mollies. Please do review the needs of fish before purchase; Mollies are difficult to keep at the best of times, and really aren't sensible choices for tanks under 30 gallons.>
Any advice regarding this behavior?
thanks Bruce
<Cheers, Neale.>

Molly question, sys. mostly     9/20/08
Hi -
I recently got 2 black mollies and 1 orange molly for my 8 gal. tank. The 2 blacks swim around together but the little orange one seems depressed - it comes out to eat, swims around by itself for awhile, and then goes down and sits on the bottom of the tank. It's fins move fine and there is no discoloration on its body. Someone told me it could be lonesome. Could this be true? I'm new to fish and would be happy to get it a friend.
Thanks
<Hello Sharon. Mollies don't get "lonesome" as such; they are gregarious to some degree, but not compulsively so. Since you have three mollies already, they should all be fine. Now, the thing with Mollies is this: they're delicate and one of the first signs of ill-health is something called Shimmying, essentially where they stay in one place, often resting on the bottom, sometimes rocking, but almost always flapping their fins. It looks like they're treading water. So, if you have a Molly that isn't swimming about all the time, ideally grazing algae from rocks and plants, you may well (most probably) have a problem. Mollies need a big tank for a start: 8 gallons is simply not viable. You will need at tank AT LEAST three times that size to even begin to provide them with the space and water quality they need. Next up, they don't do well in plain freshwater, at least not in aquaria. You need to monitor in particular hardness and pH. Because most folks like to keep things simple, the easiest way to provide the right water chemistry is to add marine salt mix (not "tonic salt" or "aquarium salt"). Go ask your retailer for a box of salt of the sort used in marine aquaria. That's what you NEED. Add 6 grammes per litre of water each time you do a water change. That will make the aquarium slightly brackish, and your Mollies will be MUCH easier to keep. Do see here:
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
Cheers, Neale.>

Mollies and Gourami's: headed for disaster? 6/19/08
Hey crew,
<Hello>
You're site is beautiful and as a fellow website/ forum administrator, I can appreciate and enjoy lengthy pre-email checklist.
<Sad that it is necessary.>
I'm hoping this isn't a repeat. I am a college student who recently moved into my own (very tiny) apartment. I have always been fascinated with aquariums and planned to get one as soon as I got my own place, but have nearly zero previous experience, besides the handful of goldfish I won and promptly killed as a child at the fair. So about 3 months ago I waltzed into Petco and on the recommendation of the 'fish expert' I purchased a 5 gallon Marineland hexagon tank with a cartridge and bio-wheel filter and light attached to the hood, gravel, 2 flat river rocks, 2 good sized plastic plants, a small castle that has two caves.
<Tiny>
I set up the tank with bottled spring water and waited a week for the water to cycle. It passed the water test and I purchased (as suggested) a paradise fish, an Opaline Gourami and two Black Mollies.
<Oh no>
It was at this point (big mistake) that I decided to do my research and read through Freshwater Fish for Dummies. I now know the tank is way too small and our tiny Black Mollies need a tank with some salinity and are being bullied by the now much larger Gourami's.
<Really it is too small for all of these fish, the paradise fish reaches about 4 inches, the Gourami about 6. The hex tank is probably not much more that about 8 inches wide I think.>
One molly died a day or two after we brought it home and just wasn't eating from day 1. Now, 3 months later the remaining Molly has large white patches and white flakes coming out of her gills, which my research tells me is Columnaris (a common petstore Molly disease). I have been treating it for about 3 days with Maracyn 2 (as recommended on a few websites) and the patches have disappeared for the most part and the Molly seems fine.
<Good, although the Maracyn most likely nuked your biofilter, so lots of water changes here.>
The two Gourami's seem to be thriving.
<For the moment, as they mature aggression will most likely follow.>
They have grown inches and have gone from nearly white to very dark and rich in color. They seem to get along great and are very active and fun to watch, but they continue to bully the Molly who retreats to the castle cave or plants.
<Expected.>
I do a 25 percent water change on Sundays and change out a cup of water twice during the week. The tank is kept super clean and I use only spring water. I feed them color promoting flakes, veggie tablets and freeze dried blood worms in small increments throughout the day and I fast them one day a week.
<Good>
I literally do not have space in this apartment for another, or a bigger aquarium, but I plan on moving and getting one next year. Am I just wasting time buying medicine and special veggie food for this very stressed out Molly.
<Probably, they are very sensitive in freshwater, best to find him a new home.>
Will it just continue to get sick in these conditions?
<Most likely.>
Is it suffering or can I make this work for another 8 months?
<Does not sound like he will last that long, can he be returned to the store?>
I just want to know if I am torturing this fish by keeping it in this tank or can I keep it this way as a temporary situation?
<It will most likely not survive much longer in this environment, and once it is gone the other 2 fish may turn on each other.>
Am I a horrible person for doing this to these fish?
<Not as long as you take steps to rectify the situations.>
Give it to me straight please.
<No holding back.>
Cheers - Jacqueline
<Chris>

Update on My Molly Tank & Marine Salt Use 05/25/08
Hi Neale,
<Kathy,>
The mouth/eye/body fungus problems seemed to be under control now. I have done seawater dip three times this week along with medication. It works very well. So, I want to thank you for your advice (although a few mollies acted miserably in seawater).
<Yes, they may well look unhappy. But they won't be harmed.>
Today I bought a bucket of marine salt (Brand: RED SEA). I am planning to switch Livebearer Salt to marine salt, but I have a question and hope you can help me.
<Yes?>
Our tap water PH is 8.2 (very hard water) because I live near Lime house and the water runs through lime. I am wondering if using marine salt will increase PH.
<Seawater is self-buffering both against pH drops and pH rises. Adding marine salt mix to hard water should cause no problems with pH or hardness levels. Quite the reverse in fact, as you'll see many marine fishkeepers actively adding sources of carbonate hardness to artificial salt water so that they can raise the hardness and stabilize the pH even further.>
I know mollies like hard water and high PH, but I am afraid higher than 8.2 can be a problem.
<They won't be at any risk at all.>
Thanks again!
Kathy
<Cheers, Neale.>

Aggressive Gourami & Molly Tank Salinity 4/5/08
Hi Neale,
<Kathy,>
A few questions about Gourami and molly... Hope to get some advices from you.
<OK.>
1) I have 2 male Gouramis and 2 Cory catfish in a 15G tank... Though I have been thinking about adding a couple of fish, I almost have to give up this idea because one Gourami is very aggressive to all the other 3 fish. I am especially surprised he is aggressive to catfish. Is this normal?
<Can be. Gouramis, particularly male Trichogaster trichopterus (the Three-spot Gourami) can be territorial. I personally don't recommend male Trichogaster trichopterus as a community fish. Other Gouramis are less commonly causes of trouble, though it does sometimes happen.>
Knowing Gourami is sensitive to high nitrate, more regular water changes are applied to the tank. I try to do it quickly and make sure water temperature is the same; however, not matter how careful I am, one or both Gouramis would scratch against glass a few times during/after water change. I do not medicate them because this happens almost every time I do water change. So, I assume it's not really a parasite problem, just them being stressed a little bit. Is this very common? Is there anything I should try to do so they can be "HAPPIER"?
<Don't worry about it. It is normal for fish to scratch themselves once in a while just as it is for your dog or cat to scratch themselves. Doesn't necessary mean there's anything wrong. You might check you're using enough/the right dechlorinator, because traces of chlorine or chloramine might irritate the fish without actually causing serious harm.>
2) A year ago I started this new hobby with 3 mollies. Now I end up with 200 fish!!! Fish keeping was totally new to me at the time and I did not read or do any research before I entered this new hobby. Fish store suggested me to get mollies to start the tank and I just took their suggestions. I guess half of beginners must have experienced the same problem as I do now. I keep all mollies in 3 tanks (38G/40G/65G males and females are separated now).... could be overstocked, but fish stores do not want to take them until they grow to certain sizes so they can sell them.
With many fish in one tank, it's not easy to keep all of them healthy. My question is, if I see one scratch or seem to have mouth fungus, should I medicate the whole tank if QT is not available? I do not wish to use medicine if it's not absolutely necessary. These mollies are kept in brackish water (salinity: 1.003). Should I increase the salinity to 1.006? Will this help to get these problems under control?
<SG 1.003 should be fine in terms of ensuring good health. Raising the salinity won't dramatically alter things. Mouth Fungus for example is bacterial and not affected by salinity at all. So yes, treat the tank with medication. You might want to get a bit more "cruel" in terms of how many fry you allow to survive. Most people who seriously breed livebearers end up with too many fry. Often they keep some sort of predatory fish to "dispose" of some of the fry. Angelfish for example are brilliant at this! But since you're keeping brackish water fish, you might enjoy something like Knight Gobies or Waspfish (Neovespicula depressifrons). These latter fish are utterly adorable puppy-like fish, and when you don't have fry, they happily eat earthworms and, with a bit of coaxing, frozen foods.>
I cannot wait to see them grow bigger so I can give some away to the local fish store.
<I know the feeling! But it's great when you get a bunch of money or credit to buy more aquarium stuff!>
Thanks!
Kathy
<Cheers, Neale.>

Mollies, sys. period
I have neon tetra, black widow tetra, swordtails, guppies, mollies, clown loach, Corydoras and danios the female Sailfin molly has just recently started looking ill as if she has shimmy but she also has white on her fins
they look like they are sticky, I have had mollies years ago with no problems in ordinary tropical freshwater setup I do not know what to do. I have given her 2 salt baths up to now she seemed better only for a while.
Any help appreciated, apologies for being so long worried as I also have guppy fry I have purchased another tank for my pregnant fish.
Elizabeth
<Please see here for more on Mollies:
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
The bottom line is that Mollies aren't compatible with standard community fish. At the very least they need very hard, high pH conditions with near-zero nitrate. Nine times out of ten they need slightly saline water as well. So fine with salt-tolerant fish (e.g., Guppies, rainbowfish, glassfish) but otherwise not reliable community fish. Cheers, Neale.>

Molly tank 3/7/08
Hello,
First off I just wanted to say I just received Neale's book "Brackish Water Fishes" and what a great wealth of information it has! I found most if not all my questions answered or at the very least a fine place to start to research more.
<Thanks! Glad you enjoy!>
I wrote earlier about my slightly brackish molly tank and since then it has been cycled thoroughly and properly, had a few births and overall no issues. I had been interested in growing more plants so I did gradually lower the SG from 1.005 to about 1.003-1.002 and I have had great success with Val.s, Anubias, sags and even wisteria and Anacharis all in about a months time.
<Very good.>
I have 8 of the 2 inch variety of Mollies in a 20 long, 2 males and 6 females and they seem to have adjusted fine and have had no issues.
<Likely yes. Even a *little* salt seems to make a huge difference with Mollies, which is why I consider adding salt to Molly tanks a no-brainer.>
My question is on Filtration. I had been running a BioWheel 150 AND a BioWheel 100 together, but it seemed to create way too many micro bubbles (and current) because of the proximity I had to place them and even though I still have good circulation and no gasping fish I was wondering if this was enough filtration based on my stocking levels, my SG and length of my tank (30" long, 12" tall, 12" wide).
<Likely fine. The acid test is to use your nitrite test kit; if you get a zero result, then you have at least adequate filtration. In any case, add together the filtration you have, and make sure the turnover is not less than 4 times the volume of the aquarium in turnover per hour.>
I do run an air-stone at night when the lights are off since the tank is moderately planted. My fish actually seem to like this better and use more of the tank now to swim and congregate but I want to avoid problems in the future. Any help would be greatly appreciated.
<If it works, and the fish are healthy -- then that's all you need to know. Keep an eye on water quality as your fish multiply of course, and clean/replace filter media as required to keep things working properly.>
Oh sorry, one other question. In using sand as a substrate ( I have Aragonite sand mixed with a bit of gravel, maybe 2lbs to the 15 lbs of sand) what is the proper way to vacuum? Is there any need to go into the sand or just hover the siphon over it and stir it up a bit with my finger or a piece of tubing?
<Either; plants oxygenated the sand with their roots, so you don't get anaerobic decay in planted tanks. I'd recommend simply scooting over the sand with the siphon and not doing too much stirring, since that would damage the roots. Feel free to add some Malayan livebearing snails if you want; they do a great job of cleaning sand. Shrimps would work in this tank nicely too, certainly Amano shrimps, and likely Cherry shrimps too (the latter seem to do well in my very low end planted brackish water tank with Limia and gobies). 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 your site that the issue may be constipation, but she didn't touch it. I don't notice any growth on her gills, but she is much more lethargic than she used to be. I've only had her for about two weeks.
<Sounds doomed to me... Unless you're prepared to raise your game here the fish isn't going to live long.>
I put a pH-balancing tablet and an ammonia-eliminating tablet into the water.
<What on Earth are these items? OK, let's make this crystal clear: there is no such thing as an ammonia-removing tablet. If they sold you this in the store, they obviously see you as the perfect customer, i.e., you'll buy anything. What makes ammonia go away is the biological filter, which you (I hope) have in place by cycling the aquarium for 4-6 weeks before adding any fish. Or else you took live media from another tank. But please tell me what you didn't do is stick two Mollies into a brand new aquarium. If you did, you may as well have stuck your fish on the barbecue for all the chance they'll have of surviving. Now, the "pH tablet" is something you should stop playing with. At this stage in your fishkeeping career you should not even be thinking about changing the pH or hardness of the water. You first test the pH and hardness of your tap water, and then you buy fish that will thrive in it. If you have soft water, but want to keep livebearers, then buy some MARINE salt mix, and add a certain amount (I'd recommend 6-9 grammes per litre) into each bucket of water added to the tank. Mollies MUST have hard water, and if you water is soft, adding marine salt mix will raise that hardness as well as the salinity in a safe, convenient, and inexpensive way.>
I now have a heater and ensure that the temperature stays around 80 degrees Fahrenheit.
<Thank the Gods!>
I am trying to grow live plants in the tank. She hovers over the bottom of the tank and her gills are opening fairly rapidly.
<Dying. This is called "the Shimmies" and indicates when Mollies are being kept chronically badly.>
Also, I noticed that after a while the rocks in the water start to emit a blue dye.
<No idea what this is. But GET THOSE DAMN ROCKS OUT NOW! Nothing you put in a fish tank should do this. ONLY buy aquarium-safe rocks.>
I have cleaned out the rocks thinking that was the problem, but she is still showing the same symptoms.
<Doubt the rocks are the key thing here, to be honest.>
Could the problem be an internal parasite?
<Nope; bad fishkeeping.>
I was also wondering if she might be pregnant, but I don't know the signs of pregnancy.
<May well be, but this isn't what's causing the problems.>
Any advice you could give would be helpful!
<Read a book. Please. The only way you could be keeping this fish worse is by forgetting to put water in the tank. You are doing everything wrong. I really, REALLY want you to enjoy this hobby, and even more want that poor little fish to survive. But you MUST raise your game. Short term: stop feeding the fish until you buy a NITRITE test kit and learn how to use it. Do 50% water changes daily for as long as you detect nitrite in the water. Add marine salt, not less than 3 g/l. Don't use "tonic salt" or "aquarium salt" or anything like that. You want the stuff marine fishkeepers use because ONLY that will raise the carbonate hardness along with the salinity. These perform together to make Mollies happy. Once you've done that, start saving your pennies for a bigger tank; not less than 20 gallons.>
Thanks,
Cara
<Good luck, Neale.>

Mollienesia: health, environment    2/19/08
Hi there,
I just found your website and it's amazing. Have bookmarked it for future reference :)
Just have a small question. I got a new Dalmatian molly today as a present for my newly cycled tank. I first found you whilst looking up his odd behaviour. He's been swimming rather strangely -tilted to one side when swimming straight, when stationary his head will drift slowly upwards and he'll stay like that for a while before swimming backwards (still with head vertical) and rubbing himself against other fish. At first I thought it might just be a quirk, but I checked out nitrite etc just to be sure. They're all fine. I wanted to be sure it wasn't a swim bladder infection or anything, so I started watching him a bit more closely. I noticed he's got a small injury just above his mouth on one side, and it's this side that he rubs against other fish. I'm quite worried he might have an infection but am not sure how to tell, and if he does whether I should quarantine him or not. The injury also looks very clean, so there is a chance that it's slightly older and healing and it's this that's caused his behavioural change.
Please help!
A very worried Su xx
<The first thing to ask is whether this Molly is being kept in freshwater or brackish. While these fish *can* be kept in hard, alkaline freshwater conditions, under aquarium conditions they are much easier to maintain in brackish water conditions. Around 10% to 25% seawater salinity (around SG 1.002-1.005) is ample. You need to be using marine salt mix, not tonic salt, when keeping Mollies because it is the extra carbonate hardness as well as the salinity that helps. De see here:
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
Mollies aren't community fish and shouldn't be sold/bought as such. They need very specific conditions to work well. I have no idea what is precisely wrong with your Molly, but these "mystery diseases" are all too common when Mollies are kept in freshwater tanks and in environments with nitrate above 20 mg/l. At least one problem, known as the "Shimmies", manifests itself as water-treading behaviour, when the fish seems to rock from side to side. This could very easily be mistaken for a swim bladder infection. The Shimmies is almost entirely observed when Mollies are kept too cold, in water without sufficient carbonate hardness, and/or there's a high concentration of nitrate. The addition of sea salt to the aquarium is one treatment that helps, provided the fish isn't too far gone. Cheers, Neale.>

Black molly/general help for new fish keeper! – 02/07/08
Hi.
<Hail.>
I got my first tank for Christmas from my girlfriend as I have wanted to keep tropical fish for some time. On the advice of the store my girlfriend bought a small tank as the man in shop said it would be easier to start with a small tank, it is a Aqua One UFO 350 I think it is between 30/35 Litres.
<Garbage advice... a tank this small is very difficult to look after. As a broad bit of advice, beginners should be looking at tanks around 75-90 litres (20-25 gallons). It's just so much easier to keep good water quality and choose a nice variety of fish.>
Again after taking advice from aquatic centre we were told Molly's would be a good fish as My first fish so I now have two black mollies and one orange Molly.
<A bad, bad choice I'm afraid. Mollies are terrible fish for beginners, and too big for this aquarium anyway. Please do understand: your first purchase should always be a book, not a fish. Store advice is sometimes good, but sometimes terrible.>
However eager to be responsible and make sure my fish are happy I have done as much reading on keeping fish as possible...however this has posed more questions than answers as everybody has different advice. I am still feeding my fish every other day as advised when I bought them about four weeks ago...yet other resources recommend feeding more than once a day.
<It's contextual. With most small fish, several small meals per day is the ideal, and closest to what they'd do in the wild. Fish have (usually) short intestines, and can't slowly digest a big meal in the way we can. On the other hand, in a new aquarium, you don't have the filter bacteria to cope with the ammonia the fish produce as a waste product of metabolism. To deal with this, you scale back feeding so that the fish are producing the minimum of waste and moreover you aren't overfeeding them, any excess food simply rotting and making ammonia that way. Hence good advice is feed sparingly when the tank is "new" (which can be anything up to 6 weeks in the case of a tropical tank). Once the tank is mature, you alter the feeding to best suit whatever fish you have.>
I am also starting to think that recommending such a small tank will prove more difficult rather than easier as I am worried my fish do not have sufficient space and worried about over stocking.
<Correct.>
My water quality is fine and I am changing 25% of water every 2 weeks...yet some resources recommend weekly water changes others say once a month!
<Back in the pre-history of the hobby (i.e., prior to the 1980s) aquarists avoided doing water changes as much as possible. The idea was that "old" water was in some way biologically active and better for the fish. "New" water undid this good, so you tried your best to avoid adding any. Hence, 25% water changes per month were considered a good thing. To stop the water going yellow and smelly, you'd put carbon in the filter to remove dissolved organic materials that accumulated in it over time. Nowadays the value of new water is appreciated, especially now we have reliable dechlorinators and other treatments that make new water perfect for aquarium fish. As a result, aquarists are now advised to change at least 25% per week, and ideally more than that. You really can't do too many water changes, *providing* the water chemistry and temperature are kept consistent. Since you're changing lots of water, carbon is now redundant (in freshwater systems, anyway).>
I have also read that Molly's prefer brackish water and that I should add salt to my freshwater aquarium is this correct?
<This is a hot topic among aquarists, but the basics are these: in aquaria with excellent water quality and a hard, alkaline water chemistry, Mollies can sometimes do well without salt. But they always do better with salt, and in brackish water you have much less change of Mollies getting sick than otherwise. For inexperienced fishkeepers at least, the addition of salt is definitely a good idea.>
...Anyway to my biggest concern one of my black Molly's has recently taken to spending most of its time right at the bottom of the tank hiding amongst plants. It does not appear to have anything physically wrong with it and every now and again it will swim and does come up to feed but this is very rarely. I have noticed the other black molly acting aggressive towards it and "nipping" at it and chasing it around the tank. The other two Molly's appear fine and happy.
<Try adding salt and see what happens. Mollies sometimes develop a problem called "the Shimmies" which is named after the dance of that name, and refers to the fact the fish seem to be treading water, sometimes rocking from side to side. It's a neurological disorder of some sort. In any case, common salt acts by detoxifying nitrite and nitrate, two chemicals that make Mollies sick. You need about 6 grammes per litre for best results (I believe one teaspoon is 6 grammes, but you can check that easily enough with some kitchen scales). Stir the salt into the new water before adding it to the aquarium; don't add the salt directly to the tank! Raise the salinity in stages, e.g., do a series of 25% water changes across a few days, taking out old water and replacing it with water that has salt added. This will keep the filter bacteria happy.>
I really want to get things right so any help on any/all of the above issues would be greatly appreciated.
<Do have a read of this article:
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
Hope it helps!
Neale.>

Molly Tank 1/27/08
Hi all,
<Ave,>
I do have a question or two about my brackish molly Tank. I was having a lot of problems trying to keep my mollies in FW so I decided to go low salinity (SG 1.005-1.008) brackish tank and keep mollies that I had (3) and eventually a few Bumblebee Gobies.
<Very good.>
The tank is 14 gallons with aragonite sand, ph 8.0- 8.1, Temp 82F. The tank is not cycled. It started with 3 mollies. I did acclimate them, but I think I might have taken some bad advice and did it a bit faster than would be desired, like over several hours instead of days. Both females had fry in the new brackish water, about 18 total.
<Mollies can be acclimated between marine and fresh in less than an hour, so unlikely a problem here.>
The problem is this: first off, there was flashing, even the new-borns, occasionally shimmies, which I had in the freshwater environment which is what eventually led me to going brackish. Later in the week twitchy behavior for my male (like a nervous twitch and then get all tense) and sometimes 1 or 2 of them would skip across the top flapping tails.
<Do check water quality. Essentially, the problem with Mollies seems to be a hypersensitivity to dissolved metabolites. Not just ammonia and nitrite, but also nitrate. If you suddenly raise the salinity in a freshwater aquarium, you are placing a stress on the filter bacteria. As a rule, you can go up to about SG 1.005 without any problems, but once you go above that, the filter bacteria seem to die back or at least stop working properly. So the usual process when creating a brackish water tank from a freshwater one is to raise the salinity in stages. I'd recommend adding SG 1.005 water to the aquarium each week, replacing about 20-25% of the water in the tank. After about a month the specific gravity will be 1.005 or thereabouts. Leave things be for a couple of months. For Mollies and Bumblebee Gobies, this salinity is more than adequate for long term health. But if you did need to raise the salinity further, do it in small increments over the succeeding months, checking the ammonia and/or nitrite all the time. It's much better to choose a lower salinity without ammonia than to go the whole hog to a high salinity but have ammonia in the water because the bacteria are unhappy.>
And then one fish in particular would stay at the top and gulp for a very long time. I originally had a BIO-wheel 100, which I swapped out for a BIO-wheel 150 and a Whisper 10 air-pump and air-stone. Ammonia was reading at about .25 so I did a 10% water change, lowered the temp a tad to about 80F and the water line to get more surface agitation.
<Ah, almost certainly this was the issue. The filter is stressed from you taking the salinity too high, too quickly. Give it four to six weeks to re-mature, putting the minimum food into the tank and performing regular water changes. Lower the salinity to SG 1.005 to economise on salt usage, but step up the water changes in the short term at least to keep the ammonia/nitrite levels low.>
This morning I decided to go out and get the babies their own tank thinking perhaps the bioload was not too good and maybe the oxygen not so good either, especially with the temp and SG. I am very new to brackish so a lot of this is new to me.
<Please do read the articles on the topic here at WWM. Or my book!>
Anyway, Ammonia is 0 again or at least at the lowest color on the test, but my Male molly still has the twitches and tenses up and occasionally flashes off the filter inlet tube...this is like once today though, not like once every 5 minutes like before.
<Getting better, I guess...>
One of the females still is piping occasionally, but not for prolonged visits, like just up, gulp gulp, down.
<Mollies are distinct among the livebearers in being able to use atmospheric oxygen when the situation is bad. They gulp water from the air/water interface across the gills, extracting the dissolved oxygen. In the wild this allows them to survive in swampy environments better than other livebearers. It's a "normal" behaviour, albeit one that implies less than perfect water quality.>
Shimmies at least visibly gone. SO I guess what I am asking is do you think this is a gill infestation/infection or do you think the water quality just got really bad really quick?
<The latter.>
Also will the fish recover if water quality, maintenance and stocking are done properly in the future?
<Yes; in brackish water Mollies tend to be rather robust and durable.>
Any help would be greatly appreciated.
Keith
<Good luck, Neale.>

Re: Molly Tank  1/26/08
Thank you for the quick reply.
<Happy to help.>
I have started daily water changes and am monitoring the ammonia and salinity to keep them under control.
<OK.>
One more question for maintenance, what test kits and water conditioners can I use...meaning, what freshwater stuff is ok to use and what must be marine?
<Water conditioner is fine for freshwater/brackish/marine uses. Water chemistry test kits are normally fine in FW/BW/M though some are not; check the package. Water quality test kits are usually fine too. Medications are often fine in both, though some are not; again, check the package you have.>
Currently I have freshwater Nitrite and Ph tests and an ammonia test kit that is for both SW and FW. What about FW phosphate removers, dechlor, etc or is that not an issue because the water is treated before going into the aquarium?
<The nitrite test kit should be fine in brackish, and likely so too will the pH test. The issue with pH test kits is that marine aquarists want ones that are accurate across the high range (between 8 and 9) whereas freshwater aquarists want ones to use between 6 and 8. So the two types of test kits are tweaked to work best depending on what sort of tank you have. So long as your test kit measures 7.5-8.5, you're OK using it in brackish.>
I am guessing low salinity like .005 is probably closer to FW than Marine, but how much of a variance does the salt add in accuracy of FW tests and possible conditioners being toxic in a Brackish tank?
<As you say, not a huge impact. For the time being stick with what you have. As and when they run out or expire, switch to ones suitable for both FW and Marine, and these'll have you covered. Cheers, Neale.>

Re: Molly Tank 1/29/08
Neale,
<Keith,>
Thank you! Everything is settling in and the fish seem very happy/normal and less irritated.
<Very good.>
One last thing please: At what level does ammonia "start" to initiate the cycle and at what level should a water change be done?
<Difficult to say, but in practise you never need to allow the ammonia concentration in the aquarium to reach measurable levels if there are fish in the tank. When people are cycling tanks *without* fish they can let the ammonia level go as high has 0.5-1 mg/l safely enough, but there's no real advantage given that the growth rate of the filter bacteria is limited by oxygen as much as ammonia concentration. Hence in practise when you are cycling tanks with fishes in them, you do your level best to keep the ammonia (and nitrite) as low as possible. The bacteria will get enough of both even so. Water changes during the cycling phase should be as often as possible, but as a baseline I'd suggest 25% daily for the first week or two, and after than about the same amount every 2-3 days. After week 3 or 4 you should find ammonia stays close to (or at) zero, and nitrite under 0.5 mg/l, and you can get away with two 25% water changes per week. After week 4 and certainly by week 6, the cycle should be finished and you can switch to 25-50% water changes weekly. But these are estimates: your own "mileage may vary" and you need to follow your nitrite test kit results rather than the theory.>
I just saw that your book ( Brackish-Water Fishes: An Aquarist's Guide to Identification, Care & Husbandry) is available on Amazon, ordering on payday. Again, Thank you for the invaluable help.
<Hope you enjoy the book!>
Keith
<Cheers, Neale.>

Possible over crowding of mollies  1/19/08
Hi crew!
I have a couple of issues that I need help with. First off, I have to mollies and I am not sure what species of molly they are. The female one is a light golden color with a white underside and white fins and tail. The male is orange with little white spots on his top side and dorsal fin. He also has a white underside, fins, and tail. Can you tell me what breed they are?
<Mmm, not from this description, no. There are meristics differences twixt species of Mollienesia... see Fishbase.org re>
Laila, the female, has been showing signs of pregnancy for over a month. As soon as I noticed she was pregnant, I put her in a pregnancy net.
<Mmm... best not to move mollies much...>
Weeks have past and she is still plump with fry. I took her out of the net today after cleaning my 10 gallon tank. I decided to take her out because it had algal growth all over it. Also, I noticed the male fish was losing his appetite and hanging out around her net, which I thought was due to loneliness.
<Interesting observation/conclusion>
Last time she was pregnant, I didn't put her in a net or quarantine her in any way. I was caught off guard when I saw the fry swimming around on the bottom of the tank. The thought of them reproducing never crossed my mind. After a couple of days in the tank, I noticed that the fry had disappeared. I am new to raising fish and can use all the help I can get. Should I put Laila back in the pregnancy net?
<Possibly>
I was reading a few FAQs on your site about mollies needing a 1 to 4 ratio 1 male: 4 females. Like I said above, I have a ten gallon tank. I'm not sure it will be able to support 5 mollies with their reproduction rate.
<I agree... This is not much room>
Should I get a better tank and add 3 other females?
<A bigger tank is a very good idea... and another female or two as well>
If so, where should I get the tank and fish? What type of tank should I get? Do I have to get the same breed of fish?
--Alia Abul-Haj
<Please read here: http://wetwebmedia.com/FWSubWebIndex/mollies.htm
and the linked files above. Bob Fenner>

Mollies... sys.   12/30/07
Hello I have a couple questions for you. How big of a tank should I get to store 7 mollies?
All of the mollies had the same mother and father, can they produce fry? I have done a lot of research on Dalmatian mollies and when they say something about the anal fin and how you tell if it's a male or female. Well could you send me a picture of a male, female and a pregnant female so I know how they look so I can look out for things like that? I would appreciate any advice you can give me.
<Greetings. Some Mollies are bigger than others. The smallest varieties, like Black Mollies, typically reach no more than 7 cm/3" in size. At the other extreme, Mexican Giant Sailfins get to over 15 cm/6" in length. Dalmatian Mollies are somewhere between the two, around 10 cm/4". As well as their size, Mollies have two other issues to consider: they are [a] very active and [b] the males are very aggressive towards one another and sometimes towards the females as well. So you want to be generous when allotting space, so they can swim about happily. Finally, Mollies are highly sensitive to poor water quality, especially nitrate. A bigger tank makes it easier to maintain good water quality. Without a doubt, the bigger the better for Mollies! I'd highly recommend a tank not less than 90 cm/3' in length. Sexing Mollies is easy: the males have long, narrow anal fins that look a bit like bent sticks. Females have regular, triangle-shaped anal fins. You cannot tell if a female is pregnant by looking at it. Some people do breed from brother and sister fish, but it isn't a good idea for all the obvious reasons. Inbreeding will cause problems such as deformed fry and low fertility. So bring in new genes if you want to breed healthy Mollies by buying males and females from different batches of fish. For more, be sure and read this:
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
Cheers, Neale.>

Molly - need your expert opinion, sys., hlth.    12/5/07
Hi, I love your site. I am new to all this -
I have read and read and read on google and all kinds of sites about my specific questions but I am getting mixed information and partial answers, so I thought I would get your opinion on it.
<Hmm... Google is efficient at finding stuff, but remember that the Internet is a mix of 50% gold and 50% garbage. If you're new to fishkeeping, you will be MUCH better off buying or borrowing a decent aquarium book, of which there are many. These will be edited and written to a higher standard than most of the stuff on the Internet.>
I have a 40 gallon hex tank with a side filter / carbon filter that goes inside etc/ I have 6 small red eye tetra, 4 mollies and a female (very sweet beta)
<OK, start by chucking out the carbon. Waste of money and space. Replace with some filter wool or ceramic noodles. Carbon serves no useful purpose in most freshwater aquaria. Biological filter media is always useful. Tetras and Mollies are not good tankmates; Mollies almost always do better in salty water than freshwater, whereas Tetras (for the most part) don't tolerate salt at all.>
First of all I know I have totally stressed out my black molly because of moving her too much.
<Oh?>
Two of my females have wound up pregnant, I don't want the other fish to eat the fry. I bought one of those breeders where the mothers are up top and the babies end up going thru a slot on the bottom so they are protected.
<Never, ever put a Molly in a breeding trap. She will hate you with the heat of nova. Breeding traps are really something that sounds a better idea than it actually is. Mollies are too big for them, and really so are most other livebearers. Instead, stock the tank with floating plants. Hornwort is idea. Check the plants once or twice a day, and then remove fry to a breeding trap or better still another tank for growing on.>
First of all, one of them has been huge for about 4 weeks and for 4 weeks I have been saying, any day now! No fry yet and I have no clue when she is going to have them. Any signs I can watch for so I can get them out quickly with a net ? Do you have any pictures so I can see how big they are supposed to get. Maybe there are not really any signs?
<One problem with Mollies is that in freshwater they often get sick, and oedema (dropsy) can look for all the world like pregnancy. Another issue is some varieties have been deliberately bred to be rounded, so it isn't obvious if they are pregnant or not. Finally, many fish will eat the fry at once. Sometimes even the mothers! So the babies can literally have a lifespan of minutes, too short a time for you to observe them.>
I put her in the breeder for a about a day and noticed she seemed stressed and I felt bad because it was so small. I know mollies require lots of space to be happy. I have found very different opinions on this subject matter.
<I can't think who in their right mind would be opining that Mollies are happy in breeding traps or don't need space. As I said, 50% of the Internet is garbage.>
I took her out of the breeder and put her back in the tank with the others for about a week. Much better!. Then I decided to put her in my daughters tank which is bigger than the breeder but still small (it's like 2 gallon). (I don't have the extra $100 or so to set-up a new tank right now being so close to Christmas)
<Floating plants... floating plants... cheap, effective...>
After her being in the 2 gallon for a couple of weeks, and still no fry, I moved her back into main tank again since she seemed stressed in there.
I put some plastic floating plants at the top and there are lots of holes in the ornament that all the fish can get into.
<A two-gallon tank is really not going to work. For one thing the Molly will be incredibly stressed. Miscarriages under such conditions are common. Even if any babies were born, she might eat them because there's really no space for the baby fish to swim away.>
Those tetras seem kind of aggressive and chase the other fish and I am worried that they will eat the fry - will they ?
<As sure as God made little green apples...>
Should I get rid of those ? I can find someone on craigslist to take them probably.
<Yep. If you want to keep Mollies -- seriously -- and get babies, then your life will be 100 times easier if the Mollies have a spacious tank with some salt (~3-6 grammes per litre) added to the water and lots of floating plants. The Tetras are merely adding a complication.>
Thanks for the information.
Wendy
<We do have a nice detailed article on Mollies, here:
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
Have a read, follow the links to related articles, and good luck! Neale.>

Re: Molly - need your expert opinion 12/5/07
Thank you, thank you. I appreciate your time and your very valued opinions. I let the Molly out of the breeding trap and I am going to find another home for the tetras ASAP. The word "trap" should be an indicator huh ? :-)
Your awesome.
Wendy
<Cool. Glad we can help. Mollies are among my favourite fish, and when cared for properly EASILY fill a tank with colour and entertainment-value all by themselves. That's why I recommend people keep them alone so they don't have to make compromises to allow for their tankmates. Give the Mollies 100% of what they want, and they'll repay you handsomely! Colour, activity, sex, and babies. What more could you ask for! Cheers, Neale.>
 

Water Flow and Mollies
I have read THOUSANDS of pages and researched everything I possibly can
and have yet to find answers to the following questions. I am sure it's
out there somewhere, but it is probably the last page on the internet. I have a 72 gallon freshwater aquarium with mollies, a few guppies and
Gouramis.
<A bit of a strange mix because of the aggressive tendencies of the Gouramis.>
I have a Fluval 404, a Fluval 204 and a Magnum Pro with the 2 BioWheels going. I have 5 albino mollies that don't seem all that happy. They don't seem sick necessarily either. I think it has something to do with the water flow. I try to adjust the outflows so that the water hits the front corners of the tank and arcs down towards the center. This seemed to make them happy but I am not so sure any more. How should I direct the water flow for my tank?
<I would do as you have described above.>
Above the water line with lots of agitation? Below the water line with a bit of a current? Should the two Fluval outputs face each other from opposite back corners? Aaaaaaaaaaaaaghh! I am also wondering if the size of air bubbles would have any significance.
<Really Mollies are going to be much more "concerned" with their water quality; pH, ammonia, nitrite, nitrate, salt content, and temperature.>
One more, are their special needs for albino mollies that I need to know
about? All of my other mollies seem totally happy.
<Your albino forms maybe a weaker variety, but still I think if there is something wrong it is not circulation. Your Fluvals are rated for 340 and 180 gph respectively and the H.O.T. Magnum Pro no more than 250 gph. That is a total of 770 gph for a 72 gallon tank, just about right.>
Oh well, I hope you can help me or send me in the right direction. Any
information you can give me that I could really study and learn more
about fish behavior would be great too.
<There is much to peruse on www.WetWebMedia.com>
Thanks so much, Amanda Best
<Have a nice night! -Steven Pro>

Molly sensitivity and cycling
I'm cycling an additional 15 Gal. aquarium (have established 55 gal.,3 10 gal., and a 5 gal already) and put in a couple platys, 2 adult Mollies (white Lyretails) and a couple half grown white mollies to aid in starting the cycling.
<There is an alternative to subjecting the fish to harmful ammonia and nitrite spikes - do a google search on 'fishless cycling' - also, since you have pre-existing tanks, you've got a major help - just take some gunky filter media from an established tank and put it in with the filter on the new tank.  A bit of gravel from an established tank would help, as well.>
After 21 days now, the mollies appear suddenly stressed. The adult female was found dead last night, The adult male was in obvious trouble, and the two young mollies appear humped back, with swimming & breathing problems.
<Very likely all a result of the cycle, I would think.  Ammonia, nitrite, nitrate, and pH test results at the time would have given more insight, perhaps>
I give them a dip in an antibiotic solution, then put them in a quarantine tank. The adult male seems to be recovering, the small ones are still questionable. The platys seem to be doing fine, although I treated the 15 gal. tank with the antibiotic (contains Nitrofurazone) before I checked the ammonia and nitrite levels.
<A good med choice.  Especially if it is ammonia/nitrite poisoning.>
The treated water shows a trace of ammonia, and barely registers nitrite & nitrate (probably skewed by the medication).
<Any ammonia whatsoever is bad.  Any nitrite whatsoever is bad, as well.  Both are quite toxic to fish, and will cause gill damage.>
Are mollies more sensitive to nitrite, etc. than the platys? Any other suggestions?
<Some fish are more sensitive than others, to be sure.  Some of the molly strains are particularly inbred and weaker than other strains.  Another point about mollies - they do much better in brackish or full saltwater conditions than in fresh.  In freshwater, they prefer hard, alkaline water to remain in the best of health.  In any case, water changes will be your best ally right now.  Do plenty of water changes, get those ammonia/nitrite readings to zero  -Sabrina>
Thank you. Jess

Black Molly
HI guys,
<Hi! Ananda and Sabrina tag-teaming on this one... >
I have a few questions regarding black molly care. Since the tank is going to be based around them, can you give me their basic water requirements, including salt levels in the aquarium? I have read anywhere from 1 tsp. per gallon to 1 tsp. per 5 gallons... there doesn't really seem to be any consistency about the information I have read.
<A: That's partly because mollies can tolerate anything from freshwater to saltwater. You want plants, so you are probably going to want to use the really low end of brackish -- no more than 1.002. That's the specific gravity reading,  and a much better way of measuring salt levels than "teaspoons per gallon". To measure specific gravity at low levels, you need a SeaTest hydrometer -- and yes, it needs to be that specific brand. Other plastic hydrometers are designed for marine use and don't measure the low levels. The glass thermometer-hydrometers are usually calibrated to 60 degrees, so you'd need a chart to convert that to the correct value based on your tank temperature. The SeaTest hydrometer is
already calibrated to 76 degrees, so you shouldn't need a chart.>
Also, if I were to add other fish to the tank in the future, what would make appropriate tankmates for them, from their natural habitat that is?
<A: It depends, somewhat, on precisely which species of molly you get. Most commonly-available molly species show up in black morphs. And it's just about impossible to tell Poecilia velifera from P. latipinna, though you can usually tell them from P. sphenops. You may want to track down a book on freshwater fishes of the southeastern U.S. Finding some
of the other fish native to that area is going to be difficult unless you can go on a collecting trip. Only a few are available -- and sporadically at that -- in pet stores. I believe the least killifish is one you might find. <<S: comment: the 'least killifish' is a tiny livebearer, not really a killifish - Heterandria formosa is their Latin name.>> The Florida Flagfish is another. Those are difficult to find, and you want to make sure you get at least one female for every male. Otherwise, the male will go after the females and get quite grouchy. He may even antagonize the males, nipping their fins, until he shows that he's the tank boss.>
<<S: Others you might think about could be: variegated Platies (Xiphophorus variegatus), swordtails, (Xiphophorus sp.), Mosquitofish (Gambusia sp.), (even guppies ('feeder' type, if you're going for the whole 'natural' look).  Of them, the swordtails will do best with the mollies, by far.  All of these fish can tolerate light brackish conditions.  Beware mixing Platies and swordtails, as they will interbreed.  If you go high brackish, one fish to consider would be possibly the three-spined stickleback (Gasterosteus aculeatus aculeatus).  They'll take a wide range of salinity, too.>>
Lastly, could you also tell me plants that are from their natural habitat as well?
<A: There are a few plants that will tolerate brackish water, and fewer of them that are available are from the same area that the molly is native to. The Florida mangrove is one such species, and can tolerate a much higher specific gravity than most other plants. Bacopa is found where mollies are found, but I'm not certain how much salinity it can tolerate.  <<S: B. caroliniana, native to central America, may possibly tolerate low salinity, say, 1.002-ishSG, and is a pretty tough plant.  B. rotundifolia is native to the southern US, but is not hardy at all, compared to B. caroliniana.>> The last time I did some research on this, I looked into estuarine biotopes and plants in Florida and Louisiana.>
<<S:  And mollies can be found all the way on down the coast and inland into central America, and even in southern California/northern Mexico and places along that coast and inland.  Mollies are pretty widespread.  Some specific plants to play with: Vallisneria spiralis and V. americana (north American natives) will both tolerate lo brackish conditions well; Egeria densa, a US (now worldwide) native, might even tolerate low brackish; hornwort (Ceratophyllum sp.) is distributed pretty much worldwide, so that's in; Echinodorus tenellus 'pygmy' or 'chain' sword (N. and S. America).  Just some starter ideas.  Any good plant book that tells plant species origins will definitely help you here, as well.  A lot is going to depend on how strict you want your biotope to be -- if that's what you're aiming for.  There are definitely some ideas for brackish plants if you choose to break away from the biotope idea.>>
Thank you very much.
<<Always a pleasure.  Wow, we got long winded.  -Ananda and Sabrina>>

- Acclimating Mollies to Saltwater -
Hi. <Hello to you...> I sent an email before but didn't get an answer. <Many apologies.> I was wondering if you could help me with acclimating a mono to saltwater. <Ok.> My boyfriend has a 37 gal freshwater setup that includes 3 convicts, an ugly red parrot cichlid and a Monodactylus argenteus.  They look very crowded, especially as it is a higher tank as opposed to wider.  I would like to move the mono to my 55 gal reef tank.  Right now I have about 40 lbs of live rock, some mushrooms, a coral beauty angel, a purple Firefish, a scooter blenny, a yellow clown goby and a white banded cleaner shrimp.  The mono is rather large (at least compared to my fish).  We bought him about 3 years ago.  He was freshwater when we bought him and I wouldn't even consider the water he's in now brackish.  Would it be possible to put him in my tank eventually? <Sure.> Would this be too stressful? <Not if you take things slowly, although mollies can move from fresh to salt quicker than they can go from salt to fresh.> I have a 10 gallon that I could use to acclimate him in.  Is this too small? <It's a little on the small side but will likely work fine for the amount of time the acclimation will take.> If it can be done. how slowly do I have to increase salinity? <A couple of thousandths a day - say from 1.000 to 1.002, and perhaps even slower if you want to be extra careful.>
Any help you can provide is greatly appreciated.  Thank you.
Nicole
<Cheers, J -- >

- Acclimating Mollies to Saltwater, Doh! -
J-
Thanks so much for responding. <My pleasure.> I just wanted to make sure though -- I'm talking about a mono (Monodactylus argenteus) - not mollies. <Oh, I am so silly... my apologies.> Does what you wrote still apply? <Sure, in fact you can go a little faster if you want. These fish are actually saltwater fish.> Again, thanks for your time.
Nicole
<Cheers, J -- >

- Sailfin Mollie to Saltwater -
Anthony et al while Bob is away,
First off mates, this site, as I have told Bob before, is truly amazing and a help to both the animals in our care and those of us lucky enough to enjoy a small slice of the underwater world in our homes. My question is what would the crew recommend the process to take Sailfin mollies from lightly brackish (1.010 or thereabouts) to full NSW, I've got some 1 months olds from a breeding tank that I would like to move to a nano reef that has been set up for a year or so (refugia=pods =coral growth, thanks to WWM for that).  I am going to place about three of the gold x silver Sailfin crosses in my small QT tank, how much salinity move per day and over what period might make this move successful. <A couple of thousandths a day - say from 1.000 to 1.002, and perhaps even slower if you want to be extra careful.> I figure that 2-3 weeks might be a good transition time and a good QT (figure it would lower chance of stress-induced ich from the change). <Well... freshwater ich and saltwater ich are two different protozoans so you wouldn't have to worry about introducing one to the other. The change to saltwater will kill the freshwater ich.>  Once again thanks to all that WWM does,
An appreciative friend,
Joe
<Cheers, J -- >

Makin' 'em Go Salty
>hi,
>>Hello.
>I have read in books that you can change the molly from freshwater to salt water and I would like to try that but none of the books said how big the container you drip the water in should be so how big of a container would I need to drop the water at one drop per second and if you have any other ways to convert them pleas tell me.   thank you, Joey                                         
>>Wowee!  Can you really say all that in one breath?  The size of the container is only important if you plan on keeping them there, Joey.  If we're only talking a couple of mollies, then a large bowl (a gallon or two) is fine.  They'll appreciate it if you go ahead and add a small air stone for aeration, too.. just don't make it too vigorous or they'll be bashed around (or, you'll get the toilet bowl effect on 'em).  Do be sure to do this over a few hours, and WATCH  their scales!  This is really important, because that's your best sign that you're going too fast - if their scales begin to stick out like a pinecone, you know you're going too fast for them and need to add fresh water again and slow down the saltwater additions.   Marina

Mollies, To Salt or Not To Salt
I am in the process of setting up my new aquarium, a 25 gallon Eclipse and I was to have Mollies.
After reading many, many articles on-line, I still have one major question- Brackish or Freshwater????  Most of the articles recommend adding salt, however I ran across this article by Kevin Yates, "The Great Molly Myth" which totally shattered my previous beliefs about mollies.
So salt or no salt??? Thanks for reading.
Marion Allen
Brevard, NC
>>Hello Marion. I believe mollies should be kept in water with a high pH, around 7.8, and medium to high alkalinity. Salt can be added, a tablespoon per 3 gallons of water, give or take. The exact amount doesn't matter, what DOES matter is pH, and water quality. Especially with black mollies, who should also be kept in warmer temps, around 80-82F. Make sure you test your water regularly for ammonia, nitrite, and nitrate readings. Keep the nitrate level low, say around 40ppm. Feed them a varied diet, including both vegetable and protein based foods. Keep a ratio of one male per three-four females. Give the females plenty of hiding spaces, like plants, for example, so they get a chance to rest and not be harassed by the male. They can be aggressive, so make sure not to overcrowd them. A 25g can safely handle around 10 mollies, with once-a-week partial water changes. Sailfin mollies will grow to around 4 inches, so understock those.-Gwen

Mollies Brackish?  4/13/-4
Hi :)
<Hi, Pufferpunk here>
I read your information about Mollies liking (needing?) brackish water -1T to each 5 gallons.   We've a 75 gallon with 2 female adult mollies and their 35+ fry, two Corys, two shrimp (rock and bamboo), and four C.A.E.  Our question is will the addition of salt bother the inhabitants that AREN'T mollies?
<Mollies do best in salty water.  They even thrive in marine.  Your other fish won't like any salt at all.  So, either keep your mollies in FW, expecting some illness & shorter lifespans, get a 2nd tank, or return the FW fish & have a BW tank.>
Thank you for your time :)
Mrs.. D. Pontrelli
<You're welcome ~PP>

More Molly Questions
Good morning, A few weeks ago I wrote in about our black Molly having fry.  The fry are really big now and fun to watch.  I've put 12 of them in the 29 gallon and 15 are in the 10 gallon and doing very well.
The 10 gallon has excellent readings for the ammonia, nitrate and PH and we do a 10% water change every other day.  
<<What about nitrIte?>>
The problem is the water reeks even after the water change.  I rinse the filter twice a week and change it after 2 weeks.  Why the smell?
<<Are you overfeeding? And again, test the nitrites...and do NOT clean your filter media under tapwater that has chlorine. You are effectively killing your good bacteria every time you "clean" your filter. Bad idea. What kind of filter are you using? Rinse filter foam in old tank water, and make sure you have a BioWheel or some other form of biological filtration in the filter that you do NOT clean, in order to keep your good bacteria.>>
Now the 29 gallon. Momma Molly wasn't doing so good.
Checked the water and nitrate was sky high.  Did an immediate 50% water change and added some "get rid of nitrate" and it's now down to 0.25 but won't go lower.
<<Do more water changes. Are you testing for nitrate, or nitrite??>>
Momma still not doing too good, eyes were bulging and staying at the bottom not eating... Treated entire 29 gallon with antibacterial.. antibacterial treatment of tank stopped 2 days ago and nitrate still at 0.25..
<<Keep testing for ammonia, nitrites, AND nitrates. Antibacterial meds will kill off your nitrifying (good) bacteria and you will have even more problems.>>
Then Momma got some white spots so again 30% water change and added a quick "cure ick".  First treatment yesterday.  Should I do another "cure ick" treatment today?
<<What do the directions say on the package?>>
Changed to the food to your suggestions of Spirulina and BTW all fish love it.
This morning Momma is swimming a little bit more and back to eating although she seems a little disorientated.  I would like to transfer the 15 babies from the small tank to the large tank and put Momma and another orange female Molly that I suspect is pregnant in the small tank.  Is this a good idea?
<<No>>
as I think Momma is stressed enough as it is and I don't like the smell of the small tank.
<<You really need to do a lot more water changes in order to get your tanks into better condition. Make sure when you do your water changes that you are adding water that is the exact same temperature as what is in the tank, and use a good dechlorinator. -Gwen>>
Thanks so much for your wonderful site and all the helpful information. Monique

More Molly Questions
Good morning, Thanks for the quick reply and all the help.  You guys and gals are a Godsend.
Here's an update...Saturday morning I got up and one of the baby Mollies in the 29 Gallon was swimming around with a dead newborn in his mouth.  Looked around and there were about 12 dead ones.  Hubby cleaned that out and I called the pet store and they said they would take all my babies black Mollies...I kept 4 of them.  I suspect Momma had other babies but these ones didn't make it.
Now Momma is ick free, no more white spots) eyes are back to normal no bulging or white film), swimming around like there is no tomorrow and eating everything in sight again from the top of the tank when I feed MODERATELY and picking at the bottom (Colorbits 2 times  a week as recommended)...She's back to following my finger around the tank and seems very happy.  She's still in the 29 gallon.  I'm running a Tetratec PF300
http://www.littlefishtank.com/Reference/reviews/display.asp?idkey=221
The nitrITRES, ammonia are excellent now. the PH is a little high 7.8 and I'm doing that test every other day.  The rest of the tank - total of 3 adult mollies, 2 neon, 4 baby black mollies and 3 tetra neon are now very happy. No live plants in there just plastic.
The 10 gallon...all the babies are gone to the pet store. did a 50% water change. ran the above 3 tests and all 3 results are perfect.  In this one I'm running a TopFin for a 20 gallon.  The only fish is there is an orange Molly that I suspect is pregnant and introduced (after reading your site info on how to properly introduce) after the babies were gone.
I was guilty of overfeeding and have now learned a valuable lesson.  If someone wants to keep their fish healthy and happy don't overfeed, don't introduce too many fish in the tank all at once and as this site and all the crew here recommends. buy the test kits and sample the water REGULARLY.
I'll check into this BioWheel or some other form of biological filtration in the filter that you have mentioned.
Learning quickly but correctly and VERY thankful for all your help. Monique  
<<Dear Monique; Good to hear the momma molly is doing okay :) Your pH of 7.8 is FINE, mollies require high pH, alkaline water, the opposite of what Neons like...keeping both species generally means one is not being kept in conditions they require for long-term good health. I am so happy to hear things are on the right track for you and your fishies. Keep up the good work! :) -Gwen>>

Black Mollies in Saltwater?  6/27/04
Hi, Hope all is going well there.  
<Hi James, Pufferpunk here & all is great!>
I have a 75 gallon F/O saltwater tank.  I have heard that black mollies could be acclimated to live in a saltwater aquarium.  Have you know of success stories about this?  
<Yes, they can live & thrive in SW.  When acclimating from FW, I would use a drip system.  Put the fish in a bucket with the water from it's bag (ask for a larger bag) & slowly drip water through air tubing from your SW tank into it (you will have to tie a knot in the tubing).  Only raising the SG .001-.002/hour.  You may need to bale water out of the bucket, so it doesn't overflow.>
Also, I have a pair of false perculas, a flame Hawkfish, a royal Gramma and a coral beauty angel.  Would the mollies fit in with these guys?  
<Just make sure the mollies have smaller crevices to escape to, in case any of your fish go after them.  I have found that a heavily decorated tank can make all the difference to "smaller" fish.>
Thanks for your help, James
<You're welcome, enjoy the mollies!  ~PP>

Re: Black Mollies in saltwater
<Hi, MikeD here>
Thank you for your help.  I have one more question please....I have read that it is best to keep mollies in groups of 1 male and at least 2 females.  (I used to keep them when I had freshwater tank).  If I just added a male, would it do OK without any more of it's kind in there?<Sure. The reason they don't suggest pairs is that males are considered "drivers", ALWAYS trying to breed with females, and if kept with just one she will often break down and become ill from the exhaustion of trying to get away from him constantly...the best mix is actually 1 male to at least 4 females>
Thanks again, James<You're welcome>
James Hall