Betta problem, no useful data  - 02/21/07
I've had this particular Betta since November, and from what I've read on the FAQ, he was probably sick when I bought him-- he's always been kind of small and skinny, and at first he was unable to swim to the bottom of the tank and commonly floated on his side.
<?>
By about January, he was better and able to swim more freely; he seemed just as healthy as my other Bettas. Now however, I've noticed that in the past couple days he's started becoming listless again and he has what looks like a little sore just above his top fin. His color is kind of a dark purple where the sore is, and the sore is whitish pink. Is this a bacterial or fungal infection or something else?
<Maybe>
And how can I treat it?
<... depends on "what" it is... What re the environment? Water quality, tests? Nutrition, foods, feeding...>
I took some pictures, but the its hard to get a clear picture of the sore, and my connector cable seems to be missing... am trying to find it.
Thanks for your help.
Emily
<Not enough info. to do more than guess... Take a read here: http://www.wetwebmedia.com/FWSubWebIndex/bettadiseases.htm
and the linked files above. Bob Fenner>

My sick Betta   2/20/07
I found you online and hope it's OK to write. I have my very first  Betta fish and he has what looks like a necrotizing skin disease:  started like a big pimple, then seemed to explode into white, cottony  tufts. Now it's spreading toward his front gill and eye. It just  keeps spreading and sloughing off, and spreading again.
I have tried EVERYTHING I know (and that's not much) including  malachite, ick cure, broad spectrum anti-biotics, sea-salt, etc. to  stop it from spreading and am at a total loss now. He was responding  to food until a couple of days ago. He did eat a little today, but he  is listless and hanging out in his little castle.
He has a nice tank, good size (3 gal) and I change his water  regularly. I vary his food, keep him warm,
<How? And how warm?>
flirt with him.  He was a  funny, active fish and this is KILLING me. I cried myself to sleep  last night. I am devastated that I cannot cure him. I feel like such a  failure.
<Mmmm>
Do you have any ideas as to what he has and what I can do. I'd  appreciate ANY suggestions on potential cures and where to find the  appropriate medications. Thank you so much.
Lynda
<Not enough data to make a guess... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/bettasysart.htm
and the linked files above. Bob Fenner>

Betta Popeye with huge puss ball under eye  2/19/07
Hello,
My Betta has had Popeye for about 10 days.
<A long time>
I tried Epsom salts for a few days.
<Good>
Then marycyn2, with no results.
<Mmmm>
For the last 6 days I used KanaPlex, and his eye has gone down greatly, but still Popeye.
<Sometimes these cases can prove quite persistent... You did raise the water temp.? I would... to the mid 80's F.>
Last night he had a tiny white protrusion under the Popeye, which was never there before. This morning, it was a huge puss ball. It opened, and now he has a hole there. I did a half tank water change, and resumed carbon filtration, along with 3/4 t. of Epsom salt, hoping it will help heal the hole. His tank is 3 gal. Was the puss drawn out from an infection behind his eye?
<Mmm, maybe>
Should I retreat with KanaPlex, and how soon?  Thank you from us both, Ann B.
<I would raise the temperature as stated, and try adding Maracyn I (Erythromycin) here... is miscible with the other Mardel product. Bob Fenner>

Another Cold Betta  2/19/07
Hello,
My Betta has been with me for a year I don’t really know how old he is. He lives in a glass bowl, with a plant, glass stones, I change his water once a week, no heater but room is always 70 ,feed him 2 times a day contains 6 pebbles a day, for the last week, he has not been eating, I thought because it has been cold.
<<Betta’s are tropical fish. I do not know how many times I can reiterate that Betta’s must be kept in heater, filtered aquariums, NOT bowls.>>
Then had noticed he had some discoloring on his face and chest .Then the next morning he was on his side.
<<Likely environmental.>>
That day I followed your Clorox dip
<<?? Whose Clorox dip? Certainly, you did not dip your fish in Clorox??>>
because I thought he has fungus and went to my local pet store and bought fungus killer.
<<Treating fish in un-aerated, unfiltered tanks can be tricky.>>
It has been 3 days since. I had also tried to give him a pea, he didn't want it. Please help.                                                
<<Please get your poor fish into a proper environment.  I am exceedingly concerned about the dip you talked about.  Please explain and link me to the article you are talking about. Thanks, and good luck. Lisa.>>

Re: Another Betta Question  2/18/07
To the wise WetWebMedia Crew:
<Howdy>
I emailed you a while ago about my Betta, Sushi. Well, he's getting worse but I've managed to take a couple pictures of him. I'm really hoping you can help me out.
<Mmm, unfortunately, these pix won't open up for me...>
Sushi lives in a 2 gallon aquarium with silk plants. The water is filtered (not a carbon filter) and heated to 82 degrees. All tests have turned up normal and I'm keeping an eye on the nitrates because of the Epsom salt I'm adding.
<Good, along with ammonia, nitrite>
I know that he's constipated because he hasn't used the bathroom is SO long. But nothing works. I've starved him, fed him peas, fed him daphnia, I give him Epsom salts.
<Time...>
Here are a couple pictures for your consideration. I shrank them to what I hope is a manageable size for you. I know they are not the best quality and for some reason they look a bit yellow (his tank water is a little tinted from the Maracyn 2 I started him on yesterday)
<Okay>
I would appreciate any help you could offer me.
  Sincerely,
  Ashley
<Nothing more to say Ashley... hang in there. Bob Fenner>
 

Betta Problem    02/17/07 Hi, <Maureen> I (desperately!) hope someone can help before I lose my little blue buddy.  I just can't seem to find anything that matches this, and my husband, who grew up with fish, says he never saw anything like it.  My Betta has some sort of fuzzy, dark stuff growing between and on top of his scales.  Could it be velvet? <Mmm, doesn't look like this... though the common name may indicate otherwise...> I thought velvet was supposed to be gold-ish under a flashlight. <Yes... a very fine dusting appearance>   Or could it be 'fur coat syndrome' a dermal bacterial that anabantids can get (supposed to be deadly within a couple days). <May be> I've been treating with Quick Cure (5 days now), in case it's a parasite, because he was breathing rapidly and flashing, but to look at it, it really just looks like fuzzy bathroom mold.  I started him on M1/M2 yesterday, today his breathing seems better and he is a little more active, but the brown stuff just won't go away.  I didn't see anything anywhere about brown fungus, so I haven't tried any anti-fungals yet. I've attached a picture, if it helps at all.  You can see where some of his scales are totally covered (not shiny) in this junk. Thanks so much for any help you can give, Mo <I would avail yourself of aquarium salt here as well... and monitor ammonia, nitrite... as you may well have killed off all nitrifying bacteria with the Formalin... See WWM re... Bob Fenner>

Re: Betta Problem  2/18/07 Hi Bob, <Maureen> Thanks so much for your quick reply.  I've been reading many of your posts over the past weeks, trying to do some research, and really do appreciate your expertise.  For some more background info, he's currently in an uncycled hospital tank, 2 1/2 gals in a 5-gal tank, temp is 78-80, water is from the tap, aged and conditioned (AmQuel+/NovAqua) and 1 tsp salt/gal added, temp and pH checked, using an airstone for aeration/circulation. <Good... do seek out some source of "cycling"... best is some sort of sponge or box type filter (air or mechanically driven)... with the media cultured elsewhere...> I left the water lower so he could get to the top since he looked weak, and he hates the flow, it makes him stay on the bottom more, which led to more rapid gilling (painful for him, and for me to watch as well, hence the airstone solution).  I've even seen him cough up a little clear mucous twice.  I've been monitoring all the levels daily, since M2 can cause cloudiness, and have been doing 50 to 100% daily water changes accordingly. Numbers-wise, I'm not sure if the local water company had raised the pH on us recently, <Good point... the tap/source water is not "consistent"> it's now 7.5 or 7.6, I don't think it was ever that high before (I used to use those crappy test strips, but now use the liquids). The only other odd thing I noticed recently was the total alkalinity has been lower than usual, about 40 ppm (scary with the pH issue).  I've picked up some sodium biphosphate to try to drop the pH, slowly, since I was concerned about adding acids. <Good... is safe, effective> Anyway, I'm trying to keep the ammo/nitrites at 0, but the water seems to be clouding up as fast as I can clear it.   I'm really hoping that it's just from the meds. <Mmm, this and the lack of biofiltration... keep monitoring, doing the water changes... looking for that filter> If it's bacterial, coming from whatever this junk is on him, <Is not> I'm afraid he won't make it.  It's now covering his mouth as well as his belly.  It starts as really tiny dark specks (have to see it with a mag glass) and then grows from there.  Someone trying to help me on the boards did suggest it might be slime coating gone awry from the formalin, but I don't know. <Is very likely so> I really don't want to give up on my little buddy, he's been such a trouper through all of this.  Would a high temp/higher salt dose hurt or help at this point? <The mid-80's F> Thanks again so much for your wonderful help, Bob. Mo <Welcome. BobF>

Betta constipation, dropsy, or tumor?    2/16/07
Hi,
<Hello - Jorie here!>
I have grown very attached to my Betta fish called Gil.
<I understand - Bettas are wonderful pets, aren't they?>
Within this last week I have noticed his stomach has swollen quite large. You can see two even sized lumps sticking out from both sides on the upper half of his body when looking at him face on. His scales which are usually dark plum are very pale around these swollen lumps. The fish himself is still very active - swims backwards and forwards and acts chirpy as usual. He has not lost his appetite and still rapidly consumes his fish pellets. It is only the swollen lumps on his body that are concerning.
<Three possibilities come to mind: constipation, dropsy, or a tumor.  Are Gil's scales sticking out when you look at him from above, sort of "pine cone" like? If so, this would likely indicate dropsy. Take a look at this link to see if Gil looks this way - http://www.fishjunkies.com/Diseases/dropsy.php >
I think that maybe he has a blockage. A man at our local aquarium took a look at Gil but was unsure about what was wrong with him. The man said that it doesn't look good - yet Gil's behaviour still seems to be perfect.
<I agree.>
The man said that he may have some sort of blockage. He said to try feeding him worms and gave me some sort of antibiotic tablet (I can find out the name if nec.). I put 1/4 of this tablet in his water. He also said that worms are good for there digestion. I have tried feeding Gil worms before but he took no interest in them. I tried to feed him some worms again today and he ate them. The difference is that I fed them to him one at a time.
<If this is plain ol' constipation, you could try feeding Gil a cut up frozen, then thawed pea - if he'll take it. Seems to be a bit "hit or miss" with regards to Bettas accepting this as food.  You could, also, soak the pea with in a drop or two of garlic - I like to use Kent's Garlic Xtreme to help stimulate appetite.  I don't agree with the shopkeeper that worms will help relieve constipation - in fact, it is my understanding that feeding a diet too high in protein (incl. black and bloodworms) can cause all sorts of health problems.  What do you generally feed Gil? I like to alternate between Betta pellets (only 3 once per day), frozen, thawed bloodworms (4-6 worms per day) and Mysis shrimp (1-2 shrimp once per day).  If you can't get Gil to accept the pea, you could also try Epsom salt - this is magnesium sulfate and does a good job relieving fish constipation.  The proper dosage is 1 tsp./5 gal. of water.  That's my first suggestion.  If his size doesn't shrink after a days of pea feeding (even possibly a day or two of fasting) and/or Epsom salt, then likely we aren't dealing with constipation.
Again, if the fish looks like a pinecone, then we are likely dealing with dropsy, a term that's used for a wide array of issues that the link provided above does a very nice job summarizing.  Generally speaking, though, improving the fish's water conditions, coupled with an Epsom salt treatment will relieve this condition.
The other alternative is that the fish has one or more tumors, which, to the best of my knowledge, aren't treatable.  I've found that Bettas are quite susceptible to developing tumors in their older age (which, for a captive Betta, is somewhere around 2-3 yrs.). How long have you had Gil?  More than 50% of my Bettas have developed a tumor in his aged years, and sadly, there's nothing you can do to help.  So long as the fish is swimming and eating, and otherwise behaving normally, all should be well and he can live a good deal longer with the tumor.>
Do you have any other advise or information about his illness? I really love this fish. I would be most grateful!
<Hope I've helped.>
Some information about his environment:
Gill is a sole fish in a tall 'flat sided' - round bowl. In his tank there are large rocks (no gravel) some crystals and two bamboo shoots. I found an internet site that said it is safe to put bamboo shoots with Betta fish. The shoots have been in his tank for the past 6 months - since we bought him. He lives in the bathroom next to a window. His tank gets dirty very quickly - probably because there is no gravel. I change his water at least once a week sometimes twice. I use Chorine Neutral, Seachem Stability (aerobic, anaerobic and facultative bacteria), Ph down and salt. I feed him 3 pellets morning and evening- but not by the clock.
<Well, the one thing I would suggest you can improve upon is this fish's environment. Bowls are not a good way to keep any fish, and I recommend keeping a single male Betta in a minimum 2-3 gal. tank, with a filter and a heater.  The Marineland 3 gal. Eclipse is perfect - it's big enough to house a 25 watt submersible heater, and has mechanical and biological filtration.  Doesn't run more than $45 or so.  When a Betta is cold (ideal Betta temp. is a stable 80-82 degrees F), or otherwise stressed due to poor environmental conditions, this can, and likely will, compromise its immune system, rendering it more susceptible to disease.  Best thing you can do for Gil is move him into nicer digs - his health will likely improve with the stable temperature and improved water quality.
Also, I'd suggest cutting down to one feeding per day...if it is constipation, that will help. Do mix up the pellet regime with worms and shrimp, though - Gil will be thrilled!>
Thank you,
Jade & Gil
<You're most welcome.  Best of luck! Jorie>

Sick Betta, env.   2/13/07
Hi there,
I am writing about my Betta fish.  I have had him for about 4 weeks and he is acting very lethargic. Until now he was in a 2 gallon hexagonal tank.
<Heated?>
Yesterday I moved him to a smaller 1 gallon filtered tank.
<Cycled?>
In both tanks he seemed  rather lethargic but with the smaller tank he is moving even less than normal. Redfin (the fish's name) has two small silk plants, two small plastic plants and a bridge for hiding.   There is an inch long ghost shrimp in the tank too, to clean up the tank.
<Good choice>
Would a Cory (or anything else) be an appropriate tankmate?
<Mmm, no... not enough room to be stable>
I am only 11 and when I have $15 I am going to buy him a heater because I am worried that he is cold and that is what is making him lethargic.
<Ah, yes... you are correct/right here... Needed to have the heater ahead of the Betta>
  He also seems to be losing a little color around his head.  What do you think?  Mike H
<Please read here: http://www.wetwebmedia.com/FWSubWebIndex/bettasysart.htm
and the linked files above. Bob Fenner>

I need help, PLEASE! Betta loss, worms - 02/11/2007
I'm needing some advice. I read through your whole site about parasites, diseases and other sites as well. I haven't found anything resembling my little aliens that popped up in my fish tank. I have had a male (Vinny) 1 and 1/2 years and female (beautiful) I've had for 3 months, both Bettas. They are in separate tanks. As for my caring for them, I think I'm doing all the right stuff. I have each of them in 3 gallon tanks. I have heaters set at 78 in both. I have live plant and natural pebbles, store bought. I take out 30% of their water and replace it with fresh and condition it, two times a week. I feed them Betta bites, about 3 a day.
<A good idea to mix in a bit of frozen/defrosted meaty food/s once in a while here>
Today, I woke up to find my male dead, with the water really clouded and little worm like creatures all over the tank.
<Mmm, highly likely the worms came afterward... introduced via the plants... not a/the cause of loss here>
If I had to guess I would say there were about 1000 at least. They were about 1/8 to 1/4 of an inch and had little legs or hairs on their body. Their heads are almost snake shaped, angular. There were also some even smaller ones I could only see under 10x. They were oval in shape, but didn't move like the others. They moved kind of like a centipede would but all around the body. I did have some snails in the males tank that came on the plants. The snails in the females tank seamed to all disappear, I think they all died, not sure why.
<Putrefaction... the cloudiness... the dead Betta dissolving...>
I did have them together for about three hours when I brought the female home about three months ago. I thought I would try to bread
<Breed>
them but decided not to and separated them. I'm scared the female will suffer the same fate. She has a little white dot on what I think is her anus,
<Is natural... an indication of readiness to spawn if you will>
maybe a worm? She also has had a big belly that gets small and then big again. 
<Ditto>
She is like a piranha and always hungry. My male hardly ever ate, like twice a week.   Anyway, I hope I have the right person and I gave you enough information. Any help would be awesome!!!! Thanks in advance for any help,  -Laurie
<These systems are filtered? Likely not... Please see WWM re Betta Systems. Bob Fenner>

Re: I need help, PLEASE! Betta loss, worms  2/12/07
Thanks for your response Bob, much appreciated! Still curious as to why they popped up post mortem if they were from the plants, part of the decomposition process?
<Mmm, yes... a bit gross... but largely as a result of the abundant (dead Betta) food source. BobF>

Multiple maladies with our Betta - 02/11/2007
Dear WWM Crew,
<Sarah>  
  Ok, I've read many things on your site in the last several weeks and have diagnosed and rediagnosed my Betta, Falstaff, several times and now am just confused.  I hope you guys can help!
   <Will try>
  A little history: about a month ago, our Betta started developing a cottony growth on his head, which we treated with some sort of tea-tree oil liquid in the water (PimaFix anti-fungal I think.)
<Am not a fan... but others here are...>
  Our aquarium store recommended it.
<Is safe... just not effective... but can/does mal-affect the environment... mal-affecting livestock in turn...>
  The directions said to remove the carbon in the filter and to treat for 7 days, changing the water by 25% after 7 days, then continuing treatment for another week if needed.  We did treat for another week and the cottony tuft went away but left a hole in its place - a white spot on his head that seemed to get smaller but hasn't gone away.     
  Unfortunately, despite the water changes, given the lack of good filtration in his tank, Falstaff's water started to get cloudy looking, and he developed Pop-eye.
<...>
At this point we stopped the tea-tree treatment, put the filter back in, did about a 90% water change, and started treating with sea salt and Maracyn-II for five days.
<Ahh, much better>
He stopped eating the first few days on the treatment and started swimming sideways which made me think he developed swim bladder disease; however, his pop-eye seemed to get a little better and he started making bubble nests again.
<A good sign>
I picked up some baby brine shrimp to entice him to eat and while he didn't swim around to get them, if I dangled them in front of his mouth, he sucked them right in.     
  Now for the last two days he's gotten progressively worse.  
<Mmm... do you have test kits for ammonia, nitrite?>
Yesterday and today he just lies on the bottom of his tank on his side, breathing heavily and doesn't move.  His color still seems good and he ate several brine shrimp two days ago but he hasn't eaten anything in the last two days.  I continue to change his water about 50% every other day and removed all the gravel from his tank
<Mmm... needs something for useful bacteria to colonize...>
so he's just got two big rocks and a live ivy plant which has been with him for the last nine months.  I cranked his heater to about 85 degrees and added a little more sea salt to his tank.  I'm worried that he might have nitrate and nitrite problems,
<Me too>
but we purchase specially made "Betta water" from the fish store that's supposed to be the right pH and everything (and we've spot checked it on our own several times) and it's always ok.  
   <... won't stay "okay" w/o nitrification...>
  Any ideas what could be going on with our little guy?  We're completely mystified.  Could he have picked up something from the plant or the gravel?   
  Thanks so much,
  Sarah
<I do think you have induced troubles with the environment here... that you should slow down on the water changes, return the gravel... and read re the ill-effects of this, the salt, the Minocycline... on WWM... Please (re-)read here: http://wetwebmedia.com/FWSubWebIndex/fwestcycling.htm
and the linked files above. BobF>

Salt For Popeye Question, Betta sys., dis. - 02/11/2007
Sorry.  Forgot to say he also has some fin rot.  Not sure when this started but I noticed upon my return.
<Please read here: http://wetwebmedia.com/FWSubWebIndex/bettasysart.htm
and the linked files above. BobF>

Re: Salt For Popeye Question... we're not communicating Roger...   2/13/07
I appreciate your taking the time to reply.
I conveyed my issues as best I could.
I am sorry if the information I provided was not sufficient.
I'll do more reading and medicating (and praying).
Thank you
<... all I ask is that you re-state your concerns in complete sentences... As if you were addressing someone unfamiliar with your situation. Can you imagine this? Write out your questions, and address them to someone who knows nothing... Send this to me/us. BobF>

Sick Bettas And Gourami - 02/09/2007
Hi. I have been looking around for some answers about my sick fish and came across your site. You seem to give much better answers than other sites I have visited and thought you may be able to help.
<Thanks for the kind words! You've got Jorie this afternoon, and I'll try to assist...>
I have a 75 gallon tank with several different types of Gourami (flame, blue, Opaline, pearl) a couple of paradise fish, 1 male Betta and a few female Bettas. All of these fish have been in my tank for several months without any problems until the last couple of weeks. All of my water tests are ok (ammonia, nitrites, nitrates, and pH is steady) and I do a 20% - 30% water change every week.
<By "OK", I hope you mean ammonia and nitrite readings are at zero, and nitrates is no higher than 20 ppm.>
Now the problems. First on of my female Bettas got what first looked like pop eye but eventually turned into dropsy.
<Separate issues, but both conditions are often caused by poor water quality.>
I treated the fish with Maracyn 2 but it did eventually die.
<Hopefully you isolated the sick Betta and treated her in a quarantine tank? If not, the medication likely destroyed your nitrogen cycle in the main tank, and you need to be especially vigilant about ammonia, nitrite and nitrate readings until the tank has "re-established" itself.>
A few days later another female Betta started to swell up like it had dropsy. I isolated that fish and treated with Maracyn 2. The swelling has gone down on this fish but it still won't eat and lost a lot of scales on one side of its body.
<Assuming that the water conditions have been good all along (again, I stress that the issues you are describing are usually caused by poor water quality, so that's the first thing you should look at), I'm curious what temperature you keep the tank at.  Bettas like warm water (between 80-82 degrees F is ideal), and if they are kept in water that's too cool, that can compromise their immune systems and make them more susceptible to disease.  Of course, since you have gouramis in the tank also, you'll have to compromise - I'd suggest keeping the water temp. steady at around 78-79 degrees F.>
Now I have a Gourami that will not eat and has some white fluffy spots on its fins and clear and white poop.
<Classic signs of fungus and internal parasites, respectively.>
I already have the sick Betta in my hospital tank and don't know what to do with the Gourami. I'm guessing it wouldn't be a good idea to put the Gourami into the tank with a Betta that possibly has dropsy.
<No, not a great idea, but you do want to isolate the Gourami from the main tank.  In a perfect world, two hospital tanks are in order, but I realize not everyone has that luxury.  Otherwise, it's a bit of a catch-22, but if it were me (and assuming the QT is large enough to accommodate both sick fish), I'd put the Gourami into the Betta's hospital tank.  The Gourami has already been exposed to whatever the Betta has, so in all likelihood, all these conditions are related.  As for treatment, I'd suggest a course of Maracyn plus Maracyn-II (you've already begun treating with Maracyn-II, so I wouldn't suggest trying a new medication altogether, but you also have to deal with the fungus.  You could also add Epsom salts to the water, approx. 1 tsp. per 5 gal. of H20.>  
Should I treat my entire tank or just remove this sick Gourami and hope that none of the other fish get sick?
<I'd suggest the later.  If you have a spare 5 gal. bucket and a submersible heater, that can even suffice as a second QT tank - it doesn't have to be anything fancy. However, if you have a choice between leaving the sick Gourami in the main tank and putting it with the sick Betta, I think the latter is the better option.  Do keep a close eye on your water parameters, though, in both the main and hospital tank, as much of what you describe is often caused by a build-up of toxins or other pollutants.
Good luck, Jorie>
Any help would be appreciated.
Thank you very much
<You're welcome.>

Re: Sick Bettas and Gourami PART 2   2/13/07
Thanks for the fast answer. Unfortunately the Gourami was dead the next morning.
<Oh, I'm sorry to hear that.>
I should have been more specific about the chemicals in my water. The ammonia and nitrites are 0 and the nitrates were around 10 ppm when I checked yesterday. PH is between 6.8 and 7.0 and the water temperature is 79.
<All good.>
I haven't added Epsom salt to the aquarium but did add aquarium salt when the tank was set up and do add salt to the new water when doing a water change. The direction say to add 1 tspn for every 5 gallons of new water.
<Aquarium salt and Epsom salt are two different compounds, the latter being magnesium sulfate which aids in digestion and reducing swelling.  This is the recommended treatment for both dropsy and pop-eye, in case you have one or more of these issues in the future.>
My male Betta also died last night. It seemed fine last night swimming and eating normally but was dead this morning. I did not see any wounds or spots on the dead Betta. There is also another female Betta and Gourami that weren't moving around very much today but I can't see any external problems on them either. If this keeps up all of my fish will either be dead of in the hospital tank soon. Is there anything else I can try?
<It seems as though you've got something very virulent in the main tank. I'd suggest putting the remaining fish into a clean, newly-cycled QT/hospital tank, and allowing the main tank to run fallow (without fish) for a month or two, in the hopes that whatever is so very quickly killing your fish will not have anything to "host" on, and thus die.  If you have/want to invest in a UV sterilizer, that's something you could try running as well.  I wish I could more specifically diagnose what is going on for you - are there any new physical and/or external symptoms?
Best of luck, Jorie>