Non-cottony mouth fungus on blue tetra? Also, black neon with balance problem  - 5/5/2006
Hi crew!
<<Hi, Helen.>>
(Before I begin, the tank details: 15-gallons (12" * 12" * 24"), quite densely planted, no CO2, nearly a year old, 0 ammonia, 0 nitrites, nitrates usually under 5 ppm (and always under 10 ppm), temperature 27 C, pH 6.5 (tap water used for water changes has pH of 7.5), 20% water changes once per week. Stocked with 3 danios, 3 black neon tetras, 2 silvertip tetras, 2 blue tetras, 1 Otocinclus. Fed once per day, alternately with flake and tetra granules, with bloodworms or daphnia once per week.)
<<All sounds excellent, Helen. Great job on the care and feeding.>>
I have two new blue tetras who've been in my 15-gallon planted tank for about a month now (they went through two weeks of quarantine first, following your excellent advice!).
<<Our advice isn't worth much without folks like you who make the effort to follow it. :)>>
One of them has settled in beautifully (chases around the danios, who are three times his size!), but the other one is far more retiring - he seems to pick a spot away from the other fish and lurk in it, changing his hideaway every week or so. In the past two weeks, I've noticed that he's developed a light, dull patch just above his mouth, on his "nose". I immediately thought "mouth fungus!"... but the pictures I've found online show that the symptom of this is a fluffy, cottony growth. His patch is light-coloured, but flat and smooth. Could this be mouth fungus, or something else?
<<I would be thinking that this is more like a "scuff" or abrasion. Enough to change the coloration but not a physical trauma to be concerned about.>>
I'm a little concerned by his lethargy, but he doesn't gasp or hang at the surface, and comes out from his hiding place in a great hurry whenever food is introduced to the tank (he's eating very well). Apart from the white patch, his general colouration is vibrant and shiny. I can't pinpoint when the patch first appeared, but having been watching it for 2 weeks it doesn't seem to have become bigger or changed texture.
<<I've mentioned this in other responses and will again here. It's always a good sign when a fish feeds and particularly good when its appetite is strong like your fish is demonstrating. I would attribute the hiding and seeming lethargy to "shyness" more than anything else. Personally, I've got fish that all but jump into my hand when I feed them and others (same species) that sort of lay back waiting for the food to come to them. All are healthy but display different kinds of behavior.>>
Do you think it would be a good idea to put him back in the quarantine tank for a course of antibacterial treatment? Unfortunately, I don't have access to medicated food in the UK.
<<I don't see any need for this right now, Helen. In fact, I don't think it would be a good idea from the standpoint of handling and trying to re-settle the fish in a new environment so soon.>>
Also, my oldest black neon tetra (had him nearly as long as the tank, and he's now about 2" long) has always hung at a bit of an angle, but over the past few months it has become more pronounced - he now hangs at a 45-degree angle, nose-up, when stationary! When moving around, he can swim normally. He's active and eats well, but I'm worried that when stationary he does seem to have to work his fins quite hard to stay in one place (he looks as if he'd tail-slide backwards and downwards if he stopped beating his fins). No
list in the horizontal plane, though. I'm assuming that this is a swim-bladder problem, and what I've read suggests that these are very
difficult to treat. Would it be worth trying him with a quick course of antibacterial medication anyway?
<<No. Never a good idea to treat for something that can't be positively identified (or as close to it as humanly possible). I've got one lone survivor out of 12 from a disastrous bout of Neon Tetra Disease (had them all in quarantine, thank goodness, and he spent an additional four or five weeks in "solitary" afterward) who displays the same type of swimming behavior. Perfectly normal otherwise but always seems a little "nose-up" when stationary. I'm not concerned and I don't think you should be, at this point, either.>>
Thank you very much for your time, and your excellent site!
Helen
<<I hope I've helped lessen your concerns, Helen. You're doing a wonderful job. Tom>>

Non-cottony mouth fungus on blue tetra? Also, black neon with balance problem - 05/05/2006
Thanks for the advice and encouragement, Tom! Though... maybe it was a little _too_ much encouragement... a simple trip to LFS to get more water conditioner somehow ended up with us walking out with a new 8-gallon heated tank, an armful of plants, and a splendid little blue/green betta (we'd been talking about getting one for a couple of weeks - and doing the research - so it wasn't _completely_ an impulse purchase... but it wasn't what we went to the store for!). Multiple tank syndrome beckons...
<<Oh, stop! I've a 20-gallon tank lying fallow right now that's virtually "screaming" for inhabitants. (I can hear it calling me as we speak, in fact!) Seriously, I'm glad I could help. (Hmmmm... A couple of Bolivian Rams, perhaps.) :)>>
Helen
<<Tom>>

Neon Tetra help needed  - 03/28/06
Hi. <Hello>  I have 5 neon tetras, 3 Zebra Danios and now 3 Fancy Guppies (1 female and 2 male) with about 7 fry hiding (mom died)<Sorry to hear that>.  When I bought my Tetras they were all fine until the next morning.  1 had lost its color from midway on back and was swimming funny (like it was drunk).  It has now regained its coloring and swims better.  However, it goes in fits of twirling about (fast circular movement; head down) and other times I can't tell which one it is in the school.  What is wrong with it (maybe got injured on the way home)?  I grew up (25 years) with Tetras (as well as the other types) and have never seen anything like this.  Do I need to remove it from the tank or is it ok to leave it in there?  Thank you, Karen in Georgia. <First, remove the Neon to another tank. What you describe, to a large degree, mimics "Neon Tetra Disease"; loss of coloration, erratic swimming behavior. I've not come across any information that describes the return of color to a fish once it's been infected, though, which makes me wonder, to be honest with you. There is a "false" version of the disease which is bacterial rather that sporozoan in its cause but it would be virtually impossible, outside of a laboratory, for you (or I) to discern the difference. Since NTD is spread to other fish so quickly and with such fatal results, you should treat this as a "worst case" to protect your other pets. Unfortunately, there is no known treatment for NTD although some claims of success have been offered; none conclusively, I'm afraid. Maintain your water parameters in the main tank to protect against any spreading of whatever this may be. Best of luck to you, Karen. Tom>

What are these things! FW Neons, Ich...    3/27/06
Dear WWM Crew,
I have recently had all my neon tetras die. The first one to go (thing 1) had dropsy and was really sad because he had been a part of my aquarium for over a year. I went to the local aquarium to get two replacements to keep my second neon company. Within 2 days both of the new guys died. I tested my water and everything was fine.
<Can't tell from here>
The following day I bought another neon tetra and named in speckles (It had white dots sprinkled over its body and fins).
<Perhaps if you named them after prophets...>
This one soon died too, followed by my second neon tetra (thing 2). I noticed my other fish began having white dots as well.
<Oops... likely not related... but ich>
(I have a flame tetra, two Gouramis, a serpae tetra) Doing my research, I assumed ich and began treating the tank with Coppersafe, as recommended by the aquarium store.
<... I would NOT treat small characins/Tetras with Copper products... but half doses of Malachite Green, elevated temperature... posted on WWM>
Paying closer attention to the tank, I can see many tiny white bugs moving on the glass and floating in the water that were not there before.
<These also are very likely unrelated...>
Can these white bugs be what is on my fish? Are they parasites hurting my fish?
Thank you for your time,
Jackie
<The initial losses were probably due to simple differences in your store/sources water quality, acclimation and your system... the ich was likely imported on some of the new fish... the bugs are likely living on the nutrients, food... You need to "step up" your maintenance, treat the ich with something less toxic (likely clean the tank a bit first, or better, treat the fish elsewhere...), and not worry re the apparent "bugs". Please read here: http://wetwebmedia.com/FWSubWebIndex/fwich.htm
and the linked files above. Bob Fenner>

Fading Serpae Tetra  - 2/15/2006
I recently bought 2 Serpae Tetras about a week ago.  They are in a 10  gallon tank with 2 fancy tail guppies.
<Like different water...>
All are doing fine, but noticed this  morning one of the Tetras looks like it's fading.  He's not the bright  orange and
black he was before.  What do you think could be the  problem?  Thanking you in advance.....
Jenny~
<The Tetras "like" soft, acidic, warm water (80's F.), the guppies, hard, alkaline, cooler water... Bob Fenner>

Dying neon tetras  02-05-06
Help! two weeks ago I did a complete change out of my 10 gallon tank, saving off half the water and rinsing the new gravel and furnishings well and added a bubbler.
<Better to limit such changes to one quarter if at all possible>
The tank is inhabited by 5 neon tetras, 5 harlequins and 1 pleco.
<Too small a tank for the last>
the water I added was conditioned by Aquafresh (or something like that)
<At least they'll have minty breath>
and the original water was replaced as well. for two weeks everything was fine,
<Only apparently>
but yesterday one of the neons became bloated and started swimming sideways. I removed it from the tank and put it in another container and it was dead
by morning. Today, I've noticed another neon started to exhibit the same symptoms. The harlequins seem to be just fine. I noticed a rust colored
deposit building up on the new furnishings. what is this deposit and what is happening to my neons? any advice you can give would be splendid!
thanks,
Chris
<The Neons don't "like" your water... or this much change this fast... Perhaps your system is "re-cycling"... also much harder on small characins than minnows... See WWM, fishbase.org re their water preferences. Bob Fenner>

My poor tetra... dropsy   1/17/06
Hello  
     I have a question regarding my tetra.  For the last 5 days or so my fish has been in the bottom corner of our 10 gal tank.  It can swim for a second
then falls right back to the bottom of the tank.  I have two other tetras in the same tank and they are fine.  I don't know what a pregnant tetra looks like
but this one is very fat and the scales are sticking out,
<... Ascites... in pet-fishing called dropsy, or a dropsical condition... aptly called "pinecone disease" in Japanese>
the side looks red.   I have read about the different diseases and it seems like the fish might
have a disease but the others ones don't.  I had my water tested when I took it into the pet shop and it is OK so I am stumped.  Would a fish not be able to
swim if it had a disease and Say the fish is pregnant how long does it take to lay the eggs?
<Depends on species... days to a few weeks>
Should I take the fish out of the tank?  IF so what is the best way?  I am not to sure on fish stuff but I don't like to see fish suffer.
<If you sense this fish should be sacrificed, placing it in a plastic bag with a little water and putting this in the freezer will painlessly euthanize it. Likely the "cause" of the dropsy here is not "catching"... Bob Fenner>

Tetra Not His Old Self  - 1/6/06
Hello again. Thanks for the information you sent me! I have one other question for you. I
got a small fish from a friend last year and It looks a lot like a Tetra. The fish was wobbling while trying to swim so I place him in a hospital tank
for about 5 days or so and treated him with Erythromycin 200mg and he is swimming a lot better and his breathing is good.
My problem is when I placed him back in my regular tank he stays about 4 or 5 inches from the top of my 60 gal!  Should I treat him with something else
or any ideas you can come up with? Thanks again Ian
< I am not a big fan of blindly treating fish. The sounds more like an accumulation problem and not really an illness. Reduce the lighting and see if he starts to mingle with the other fish after awhile. Give him a little time to get back in the pecking order.-Chuck>

Black Phantom Tetra, Webmail Issues - II - 12/25/2005
Hi Sabrina,
<Camille, my apologies for the delay in this reply.>
Thanks so much for responding to my email!  
<Of course.>
I really appreciate the service you and your colleagues provide.  
<Thank you for these kind words - we are glad to be of service.>
Unfortunately, my little Black Phantom did not pull through.  He died on Sunday night.  
<I am so sorry to hear this!>
I sent a follow-up email after this initial message that you responded to
<I fear I/we did not see this follow-up - blast this webmail!>
which mentioned he had started to excrete what looked like a thick whitish string of fecal material.  
<A possible indication of internal parasites....  other possibilities.>
This was trailing from him for several hours and his anal vent area looked a bit red and irritated to me.  Eventually, the string apparently had exited his body and he actually appeared to be breathing easier.  I was hoping against hope that maybe he still had a fighting chance, but when I checked on him an hour later he had died.  
<So sorry....>
I really hope he didn't have anything going on that has put my other fish at risk, but I suppose only time will tell.  
<Agreed.  Be keeping a close eye on your livestock.>
Thanks again for the response.  I am new to fish keeping and the information on your website has been very helpful to me.  
<I really am glad to hear this....  It's comments like these that really keep us going.  Thank you.>
Best regards and holiday wishes,
<And happy holidays to you!>
Camille Merrell
<All the best,  -Sabrina>

Rummy Nose Tetra with worm?  12/20/2005
I could sure use some help!  I have a rummy nose tetra that has a worm in
his front right fin and I have treated him with Fluke Tabs and Aquari Sol
(my tank had ick) and the worm is still in the fin (must be internal).
<Might be>
I have taken the fish out and put him in a hospital tank and  under a
microscope to make sure the worm is in the fin and sure enough it is!  I
have taken him to a fish store and chatted with a woman that has worked a
lot of science when it comes to sick fish but even she was unsure what to do
She told me she would look further for more information but could find
nothing.  The fish is breathing heavy and flapping his fins.  I am very good
with a scalpel and was thinking on cutting part of the fin off to remove the
worm (clove oil to anesthetize??)
<Mmm, possibly, but hard to do on such a small specimen...>
and then treat with an antibiotic.  Under
the scope I also found a very very light dusting of black dots that can only
be seen under a scope.  I am thinking on doing the removal of the fin as a
last resort.  I would appreciate any information you could give me as time
is running out.
Sincerely,
I. Garrett
<I would use an anthelminthic here. Please use this term in the Google search tool on WWM... Bob Fenner>

Black Phantom Tetra, Webmail Issues - 12/19/2005
Hello crew,
<Hello, Camille!>
I sent an email to you on December 1st regarding my Black Phantom tetra that had not eaten much at all for a few weeks (since being moved into a new tank).  There was apparently an issue with replying to my mail, but Don was kind enough to track me down in the 911 forum where I had also posted a message.  
<Our apologies - our Webmail system does occasionally lose (don't know how) the "tray" for responding to a message.  I'm not sure what the combination of settings is, but my laptop seems to be the only system that doesn't lose this "tray"....  So, fortunately, I have the ability to reply to you.>
At that time, the fish was showing no outward signs of illness; his color was good, no clamped fins or weird scale discolorations, etc….  All water parameters were fine, and all other fish in the tank were doing very well. He has continued to ignore food.  I did get him to take a few nibbles at some live brine shrimp last week, but he certainly wasn’t showing the same interest as the rest of the fish.  
<Disturbing.>
I generally feed a combination of flake and frozen foods and I never see him show interest in any of that (although he used to eat well in the old 20 gallon tank…).  I added 2 additional Black Phantoms to the tank yesterday hoping that more of his own kind would help him feel more secure (bringing the number of Black Phantoms from 2 to 4 in the tank).  This morning, the fish in question is hanging out at the top of the tank and seems to be breathing more rapidly than normal.  He may also have a light patch of scales under his chin (in the gill area), but its been hard to get a real good look at him; whenever I closely approach the tank he turns and swims away from me, but I’ve caught several glimpses of what may be a light skin patch….  All other fish in the tank continue to do well; everyone eats and displays a normal activity level.  The Black Phantom is the only one at the top of the tank with an increased respiration rate.  
<So frustrating!!  There really are quite a number of possibilities at this point; I would be more likely to think he may have an internal bacterial infection than anything....>
Tank specs are as follows:
55 gallon
Live plants (Anubias, crypts, java fern, Ludwigia)
Eco-complete substrate
No Co2 or fertilizers used
Inhabitants:
6 Neons
4 Black Phantoms
3 Pristellas
6 Panda Corys
miscellaneous snails that hitched in on the plants
Water parameters as of this morning:
Temp 79 F
Ammonia 0
Nitrite 0
Nitrate 5 ppm
Hardness 5 deg KH, 10 deg GH
pH 7.4
A small water change (~10%) was performed last night.
<All sounds great....  nothing at all that catches my eye here.>
Is there anything I can do for this fish?  I do have a quarantine tank I can move him to if needed.  
<I would, most certainly - if not to help the sick fish, then to protect your other livestock from contracting what he's got (if anything).  I would consider feeding him an antibacterial flake food, but if he's not eating, this is obviously going to be difficult at best.  Food medicated with Oxytetracycline would be my choice, if you can get him to eat anything.>
Any suggestions are greatly appreciated!!  If this email can’t be replied to (which was the issue with my original query), can someone post a reply in the 911 forum??  My post there is entitled ‘Black Phantom tetra won’t eat (a little long…)’ and was originally posted on December 2nd under the name CMERRELL.  Thanks for reading and I hope someone can help.  
<I'll take a look there, as well, and see if there's anything else that catches my eye.>
I really hate to see the little guy in distress!  
<I do very much understand....  My sympathies to you, and to him - I hope he can pull through for you.>
Best regards,  -Camille Merrell
<Wishing you well,  -Sabrina>

Upside down catfish and skinny tetras  09/13/2005
Hi everyone at WWM,
<Hi, Cobina!>
I am enjoying your site and I have found some information that I found interesting and will hopefully put to good use.
<Ahh, glad to hear it.>
I have a couple of questions, but first I wanted to give you a quick rundown on the occupants of my ten gallon tank.
<Okay.>
This is my first tank and I have had it for less than a year. The tank came with one painted tetra (pixie) and one upside-down catfish (Dixie, I know creative huh?). So I got a couple more painted tetras and one more ud catfish for company and tried to give them lots of hiding places (as the person before had just a bare tank).
<Some words of caution, here....  "Painted" tetras are typically tetras that have been artificially dyed; this process is quite stressful to fish and can be quite harmful.  I believe that fish that go through the dyeing process usually are very susceptible to disease.  Please don't support this by purchasing any more of these "damaged" fish; rather, give yours the best care that you can to help them recover.  With luck, they will survive and eventually regain their natural state and color.  I would also like to caution you to the size of upside-down catfish; please read here:  http://www.wetwebmedia.com/FWSubWebIndex/mochokids.htm >
Recently (almost three months ago) I found a beautiful polka-dotted loach, and a female betta and added them to the tank.
<Getting a bit full, there....  Any plans for a larger tank?  Might start thinking about it if space and money allow.>
For a long time they seemed to get along very well. The betta seemed to almost become another member of the tetra family, as she swam around with them often, and although the loach was kind of pushy under the wood with the catfish, he didn't seem to nip at the others (other than the first day when I assume it was him that ripped the back fin of one of my tetras).
<Actually, I would guess that another tetra was responsible....  but it may have been the loach.  Many loaches (not all!) can get quite aggressive.>
Then a few weeks ago the water got cloudy shortly after a regular water change and I couldn't get it unclouded.
<Possibly a sign that your tank just has too much fish/bioload for its capacity.>
Then when I realized that my daughter had inadvertently switched the washing pail with the fish pail, I was absolutely mortified.
<Yikes!>
But before I realized that my betta had committed suicide and jumped out of the tank while we were asleep and we didn't find her until the next day (poor thing). Also during this time my loach was getting quite aggressive and nipping at the other fish, and two of my tetras are getting really skinny.
<Possibly long-term results of being dyed....  Also, I begin to suspect poor environmental conditions.>
I finally got the water in order and started giving my bottom feeders sinking pellets so that the loach would hopefully stay at the bottom and not bother the tetras. The catfish didn't seem to be particularly interested in the pellets, as they would go right past (or over) them while scouring the bottom of the tank.  I thought maybe the tetras were stressed and that's why they got thin. But after reading your site, I am thinking that maybe they have internal parasites.
<A possibility, but in all honesty, I would look to environmental causes first.  Please be testing for ammonia, nitrite and nitrate....  Maintain ammonia and nitrite at ZERO, and nitrate below 20ppm.>
I am just beside myself with guilt and worry. They don't seem to be getting any fatter after having good water. If it is parasites, is there any kind of treatment? I don't want to see them just wither away to nothing.
<First, test the water, and go from there.>
Another thing I was wondering is that Dixie (my first ud catfish) sometimes gets a big belly when he/she eats a lot. But my goodness, his belly is at least twice as large as I have ever seen it. It is even sticking out on the sides. He seems to be quite happy though, as far as I can tell. Then I thought maybe he's pregnant. Is this possible? I would love to have baby catfish, but I don't know if they even breed in captivity, and I am certain that I would have to maybe set them up in another tank so the loach wouldn't get at the fry.
<I rather doubt that it's a pregnancy issue - but if it is, there will be a lot of research you'll need to do prior to being capable of raising the fry....  Figure out what species they are, and start searching.>
Or maybe he's just super fat because maybe he pigged out on the pellets after I went to bed.
<Entirely possible.>
So my questions are really:
1) Do you think that my tetras have internal parasites, and if not what do you think it might be, and if you think they are parasites how do I treat them. I don't have another tank to put them in to make a sick tank. I have a one gallon tank that I have a male betta in, but it doesn't have any filter system of any kind. What are your thoughts?
<Currently, there are too many possibilities to narrow down what might ail the tetras.  It may be completely outside of any ability to treat, if it is a health issue related to the dyeing process.>
and 2) Do you think my ud catfish is pregnant, or just really fat from pigging out on pellets, or worse I hope he isn't sick.
<Hopefully not sick.  Just observe closely for a while, and by all means test your water!>
Anyway, I know it was a long explanation, but I wanted to make sure you got all the pertinent information that you may need to assess my poor fishes.
<The more information, the better.  Thank you for being so thorough.>
I really enjoyed your website, and was very encouraged by the amount of information there.
<I'm very glad to hear this!>
I really appreciate the fact that you accept questions and that you take the time and effort to share your expertise with other fish lovers like me who are sort of new to the game.
<Thank you very much for the kind words - and chin up, whatever the outcome for the tetras, I am confidant that they are in good hands with your compassionate outlook.>
Thanks again.  Sincerely,  -Cobina.
<Wishing you well,  -Sabrina>

Upside down catfish and skinny tetras - II - 09/15/2005
Hi Sabrina,
<Hello!>
Thanks for all of your advise, but I am sad to say that the two tetras died the same night that I wrote the email. I found them in the morning.
<I'm so sorry to hear this, Cobina....>
I had the ammonia, nitrate, nitrite tested a few days before they died and they were fine.
<It doesn't take long for water quality to go from fine to lousy....  It would be a good idea to get your own test kits (preferably liquid reagent kits instead of dipstick-type) so you can test whenever necessary.>
And I even had the water tested for phosphate because of the possible soap poisoning but that was fine too. A week and a half and two water changes earlier the ammonia was high.  Now after taking out the fish yesterday, the water was really stinky (not normal),
<Likely water quality had declined from the decaying fish.>
so I did a partial water change and scrubbed down the rocks from inside the tank. It smells better now, but I need to get it tested just in case things are funny.
<Agreed.>
The catfish have been hiding so I'm not entirely sure if Dixie's belly has gone down, but I suspect that it has. Thanks for the link about the ud catfish. You startled me there, I thought that you meant that they would get really big like the Plecos do, but they say they only get to about four inches.
<A four inch fish, with so many tankmates, is a little large for a 10 gallon tank, though....  As these guys grow (and they will, though perhaps slowly), you will want to consider something larger.>
I don't know why mine aren't growing. Dixie, my first one is at least two years old (and is maybe two inches long if that)
<Uncommon....  Nutritional deficiency or poor water quality can inhibit a fish's growth and "stunt" it; do you know what conditions she had with her previous owner?>
and the other newer one, I got last October or November, and who knows how old she was when I got her, she is slightly (but not much) bigger than Dixie.
<It's all just a matter of time.>
Dixie came to me with stumps instead of fins, I guess being in a bare tank with only red rocks and one tetra, the tetra probably chewed them off. But now they have grown back. They aren't as full as the other catfish, but at least now he has fins.
<A major improvement, to be sure!  And a sign that your care is a big step up from what he'd had, perhaps.>
As far as overcrowding, I thought I was doing good. I had up to seven at one time but usually it has been five or six.
<Seven?  Five?  Six?  What?  Fish?>
The tetras are probably an inch long each, the two catfish together are four, that makes 7 and the new loach is probably three inches so that makes 10.
<Aim for their adult sizes, and add those instead....  Furthermore, the cats may get territorial as they grow (though not really "aggressive", I don't think), so a bigger space again might be good.>
I guess I didn't think the catfish were that big. They just seem so small. It was only the five (the three tetras and the two catfish) for the longest time until a couple of months ago. Maybe I should cut it back to that again.
<Or just get addicted to fishkeeping and get more or larger tanks (grin)!>
I am trying to think about what I can replace my tetras with (I still have one left that I want to be able to integrate with the new fish). and I think I may have to find a new home for the loach, he is beautiful to watch but he is possibly too pushy with the catfish, especially if I want to try making catfish babies in the future (if that is even possible).
<Agreed, wholeheartedly.  The loach's behaviour will not improve.  I would try to find him a new home if possible.>
I would Love to get a bigger tank, or maybe run this one and then a larger one with other fish. I have plans to do that when the funds allow for it.
<Sounds excellent.>
Anyway, I wanted to thank you again for your advice and getting back to me so soon.
<Sure thing.>
If you have any suggestions on what you think might be a good tankmate for the catfish and my lone tetra, I would be delighted to hear your suggestions.
<Other tetras might be a good plan, since they are schooling fish - but please do try to stay away from dyed fish.>
Thanks again.
<No problem>
Take care, and know that your advice goes far with us new fish lovers.
<Thank you for this - you are very kind!>
Sincerely,  -Cobina
<Wishing you well,  -Sabrina>

Sick Von Rio tetras?  9/13/05
Howdy WWM Crew,
    I stumbled (serendipitously) onto your site when I was looking for
aquarium plant advice.
    My 16 gallon bow front tank houses 8 Von Rio Tetras,
a few live plants, and a small number of snails that slipped in with the
plants.  Together with weekly 20% water changes, filtration is performed
by a Whisper 30 filter (I'm also thinking of adding some peat
filtration.) The temperature is 80 F.
    The tetras eat well, aren't breathing hard, appear
to swim normally, and have become much redder & more iridescent since I
got them 2 months ago.  However, the edge of the dorsal fin on all of my
fishes is milky looking (not fuzzy or spotty and the fin is not
jagged. The fishes came this way.)  The milkiness doesn't appear to be
spreading over the rest of their bodies, but I am very worried.  Does this
sound like a bacterial/fungal disease?
<Mmm, no>
  Also, pictures of these fish on
the web show 2 dark stripes on the body- mine don't :| .
Thank you from a new fishkeeper,
Anne
<A geographical variation in this species... I would not be concerned re the lack of barring, the white on their dorsals. Bob Fenner>

Pregnant neon  9/5/05
Hi,
Please help-I think I've done something awful.
I set up my new tank yesterday, but because the above neon seemed to be harassed by other fish I put the fish in the new tank.  She seems very stressed, swimming in jerky movements, in circles.
I have turned the light off .  My predicament is:
Should I put the fish back with the others or put another neon in for company? Please advise.
<I would add another neon to this ones tank>
Regards and thanks for your assistance
Jacqui
<Bob Fenner>

Silver Dollars with Fin Damage 8/21/05
I asked for help a while ago with my Silver Dollars looking extremely poorly. Ich causing large sores on their sides, and fin rot, you suggested a Furan based medicine and the continued use of Rid-Ich+. I'm now using Furazone-green (contains: Methylene Blue: 2.5mg, Nitrofurazone (Monofuracin): 122mg, and Furazolidone: 24.4 mg.) and I've doubled the dosage to one capsule twice a day as directed on the package as well as the Rid-Ich+. I've been treating one silver dollar in a ten gallon tank setup with no substrate under my 90 gallon for 10 days now. Figured this was a good location as this is a large, stressful fish and its inside a cabinet. I've noticed the major loss of ich, and the slowly shrinking sores, but the fins, though no longer discolored, have not seemed to have grown whatsoever. I was wondering what other practices I could take to speed this process, perhaps lowering the ph and adding softer water (distilled percentage)?
<After the sores are gone then the disease is practically cured. Now the fish needs to heal. Sometimes the fins get fungused too. These fungused fins to not regenerate. You will need to remove the fish from the water and clip the fins back to past the damaged area. they will then regrow but not as nice as if they were never damaged. Fins diseased back into the caudal peduncle usually do not regenerate.>
The ten gallon does have a large filter, in fact its an old, fully cultured penguin 330 Bio-wheel, I shut this down for about 45 minutes every time I add medicine. I'm only changing water when the fish seems to be breathing harder than normal, should I be changing it more often? Any specific help is greatly appreciated. Thanks again!!!
< Check the nitrates. The disease causing bacteria continue to thrive when nitrogenous wastes are present.-Chuck>

Silver Dollar Question 8/23/05
One more question please: after the sores are cleared, and their fins are clipped back, do I still have to quarantine them? Or can they go back in the 80 gal?
< Put them back into the quarantine tank until the fins start to grow back.-Chuck>

Silver Dollar Problems 8/21/05
Ok, this makes sense, the silver dollars never had good fins from the day I got them with my used tank purchase, from what I understand they are quite old fish, around 5 years old. But no matter, I'm not too much worried about the way the fins look, as long as the sores close up. How do you suggest restraining the fish out of water? Under a towel, and I imagine this should be done in intervals of just a few seconds. Thanks for replying!!!
< If you want to take them out to clip the fins then you take a large soft net and catch them. In a shallow dish you place a clean bath towel that has been soaked in the aquarium water. Catch the fish and place him on the towel and cover him up with only the section you want to work on exposed. Use fingernail clippers to trim the fins back past the damage. Silver dollars have very fine delicate scales that are easily damaged. If the areas get damaged then you might be back to square one.-Chuck>

Paralyzed Tetra 8/11/05
Dear Crew,
<Stacy>
The other day, I noticed that a tetra I've had with 3 others in a tank for over 2 years was lying on its side at the bottom of the tank.  I have no idea what caused this, and figured old age was kicking in, and he would likely die soon.
<Likely so>
The other fish are doing fine.  Today, it is still on its side on the bottom of the tank.  It is breathing, it's eyes are functioning and one side of its body is moving.  But that is all.  It's as if it is paralyzed on one side.
<Happens>
I have no idea what to do, and can't bear to let it suffer this way.  He's been this way for three days now.  What do I do?
<It is likely not suffering, but if the prospect of this bothers you, you might euthanize this fish... in a bit of water, in a plastic bag... in the freezer>
  And what is the most merciful way to put him out of his misery?  Or is there some way I can help him recover?
<Probably will not recover... but there is always a chance>
Any help you can offer is most appreciated...
Stacy
<Small tetras often only live a few years... Bob Fenner>

Re: Paralyzed Tetra 8/11/05
Dear Crew,
Stacy>
Thanks so much for your quick reply.  The poor little guy is still on his side breathing rapidly, with one fin trying desperately to swim, but no luck.  He's still at the bottom of the tank, gulping food when it comes his way.  The others are leaving him alone. I've had 4 tanks for 10 yrs and have never had this problem...It really baffles me.
I'm going to go ahead and euthanize him if there's no improvement tonight, as I just feel like he is suffering, and he has been this way for far too long.  (I found your euthanization page online after a lot of exploration yesterday.)  Thanks for a wonderful, and very informative, site for all of us "novice fish enthusiasts".  I will be doing a lot of referrals to your site in the future!  
Stacy
<Life to you my friend. Bob Fenner>

Fat Fish (tetras)
Bob,
The last several weeks I have had several of my various tetra fish look like they were going to explode... There stomachs more than double in size, they definately are breathing hard and look like they are in agony. I have no idea what would be causing this, or what should I do to protect the rest of my tank. I have a 55 gal tank and so far have had 4 fish go through this. None are the same species but all have been Tetra's.
Deb
<There are some protozoan and worm diseases of Tetras that might account for this "bloated" appearance/difficulty, as well as diets of foods that are hard to digest (some dried, some fresh/frozen)... and a few chemical possibilities. Do you modify your water quality? Utilize live plants? Please specify which types of Tetras are affected and what other animals you have in your system (good clues). Bob Fenner>

Tetras with sores
Hi there,
I have several black high skirt tetras of different ages.  The problem is as they get older and larger, 2 of them developed a sore around their mouths.
<Sores around the mouth are often times due to mouth fungus.  Which is a treatable disease, I have found that medicines from the Mardel company have worked exceptionally well.>
The largest one died and I am worried this will continue until I find the problem.  They share the tank with red serapes and a 5-6 inch pleco.
<There doesn't seem to be any sort of tank mates that would be nipping or bothering the Black Skirts.>
Any suggestions would be great.
<Make sure that the filtration is good on your tank, keep up on the water changes.  This will help keep the fish's immune system working well, and it will also offer a better environment so that fungus and bacteria won't be able to thrive.  It's best for you to set up a quarantine tank, so in the case that your fish do come down with more sores around their mouth then you will be able to remove them from the tank and medicate them.  Look at medicines like Maracyn, and even a broader based medicine like Maracide from Mardel for a good treatment for the problem.>
Thanks, Belinda
<Good Luck. -Magnus>

Tetras lost to a new tank
Gwen,
  Thanks for your fast reply - I appreciate your advice.  Unfortunately,  I think I will stay away from tetras because (maybe the water is too alkaline for them) I lost 3 different kinds of tetras when I started the tank 6 months ago. Another option might be some colorful guppies but I am concerned that they would need more salt in the water than I think some of the other fish would tolerate.    Thanks again.  Beth   
>>Hey Beth :D Don't be so hard on the tetras :) You may have lost them simply because it was a new tank set-up. Tetras are normally more resilient than most other species of fish, and are quite easy to keep. By the way, guppies do not need salt in the water. Most people think that salt prevents ich, or fungus, or does some other magic thing, but the fact is that most freshwater fish do not need salt added on a regular basis. It CAN be used medicinally, to cure such diseases, but salt should only be added when you are treating something specific. My advice to you would be to re-think the tetras, like pristellas, etc, and guppies :) Have fun!
-Gwen

Sick tetra?
I have a red eye tetra that's ballooned up on the under side; is this a pregnancy or a bladder or swim bladder disease?
<Hello...Jorie here.  I really can't say what's going on without some more information. First off, how big is your tank, how many other fish are in it (and what type), and how long has it been setup and running for? Have you tested the water recently for ammonia, nitrite and nitrate? If so, what are the readings? (Ideally, all should be at zero.) Also, what is your fish's behavior like to make you think it could be a swim bladder disorder?>
It had no swim difficulties...
<This likely rules out swim bladder disorder>
and gills quickly
<Do you mean rapid breathing? I'm not quite sure what you mean.  If it is rapid breathing, do test your water for ammonia, nitrite and nitrates, as mentioned above, and do a water change to get those readings to zero if necessary.>
What should I treat it with?
<For now, I'd say nothing. Do a water change and please try to give me some more specific information about the tank, other fish, and the affected fish's behavior so that I can better help you.>
Many thanks,
<You are welcome. Good luck.>

Characid Parasitology help sought
Dear Sir,
I feel most enthused in your marvelous efforts in elucidating parasites of Fish to the students all over the world.
I have in my attachment an appeal onto where my research work lies.
School of postgraduate Studies 
Faculty of Biological Sciences
Department of Zoology 
University of Nigeria, Nsukka.
14- 05- 04. 
Dear Sir,
I praise your academic prowess, especially, in the area of fisheries parasitology. May your efforts and strength never waver in your imbued march towards bettering nature.
I am a postgraduate research student in the above department and University, working on the parasites of Characidae in the Anambra River Basin, Nigeria. 
The following are the objectives of this research work: 
Ø There is scanty relevant parasitological information on fisheries development and management in Nigeria. An informed reason to fill the gap.
Ø Fish are the most readily available animal protein both in the hinterland areas and cosmopolitan areas of Nigeria. Our over 120 Million population is the largest consumer of fish in Africa. So, there is burning desire to ensure availability of fish in our meals thereby ridding them of these parasites. 
Sir, I am in great need of your assistance, which is inevitable to the accomplishment of this Research work. Such assistance is needed in the following areas: 
ü The latest scientific methods, materials on the parasitic investigations on Characidae. 
ü The parasites of the Characidae. 
The aforementioned are fulcrums that will pilot the research to a logical success. 
I would be grateful if my request is delivered. 
Thank you. 
Your sincerely, 
ECHI, PAUL CHINEDU 
paul_echi@yahoo.com
Thank you.
<Paul, will post your request for others response. We don't "do" research per se (but relate others experiences), but am hopeful your message will be found. Have you contacted the Smithsonian asking for reference help? I would. Bob Fenner>

Dull Neons...
Hi there, I was wondering if you could give me some advice on my neon
tetras. Today I noticed that they are looking very dull in colour and not
swimming about as much as they usually do, also one of them is bloated. I
thought this could be neon tetra disease, do you think this is the case? If
so, should I carry out euthanasia?
< If the disease is only affecting one fish then I would get rid of it. If it looks like it is going to spread to the other fish then I would treat with Nitrofuranace of Myacin. Make sure you follow the directions on the package.-Chuck>
Thanks
Fran

Black Skirt Tetra Issue
Hi. I'm new to having fish and need help. I set up my tank at the beginning of October (30 gallon). I have 3 Black Skirt Tetra, 3 Zebra Danios, and 1 algae eater (sorry I don't know his real name - it starts with a P). <Pleco works>
Earlier today one of the tetra died. I had noticed some erratic behavior and sluggish swimming over the last day or so.  He also looked as though he had bubbles on him. When I removed him from the water the bubbles were white spots, particularly on his tail. The other two tetras are now acting oddly, they are not schooling, both are staying near the top, which is odd for them, they normally swim near the bottom. What do I do? I did a water change about 2 weeks ago - the fish had been overfed while we were out of town on vacation and the tank was covered with algae. This is when I added my algae eater. All has been well until the last 24 hours or so. HELP!  
Thank you,
Allison
<The white spots are a pretty sure sign of Ich. Treat with salt. Read here for it's proper use. http://www.aquariumadvice.com/showquestion.php?faq=2&fldAuto=32 You should also be doing more water changes. Use a gravel vac to remove the old food and fish waste. This is very important when treating for Ich. Don>

Re: Black Skirt Tetra Issue
Thank you for your response!  Today the white spots look more like fluffy stuff - on the tail and fins.  It almost appears to be fungal.   
Thanks for any help you can offer.
Allison
<Please read here: http://www.wetwebmedia.com/FWSubWebIndex/fwinfectdisfaqs.htm
Bob Fenner>

Neon tetras that change colour...
Hi. I have found your information about neon tetra very useful, but I
am confused about "neon tetra disease".  I first got a fish tank two
years ago and have kept neon tetras in this time.  It didn't take me
long to notice that when they changed colour that this is bad, but the fish did not always die but change back and remain healthy.
<Mmm, Neons do change color sometimes due to "mood", time of day, interactions with each other... not always indicative of disease>
(I have had one particular neon tetra for 2 years now).  Is this colour
changing due to "neon tetra disease" or is it just stress or bad
water?
<This sporozoan infection is almost always fatal, and quite distinctive (loss of blue coloring distally): http://freshaquarium.about.com/cs/disease/p/neondisease.htm
I don't think your fish have this ailment>
I really like my neon tetras and hope that there is something
I can do about this phenomenon.
Thanks Dani.
<Read on. Bob Fenner>

Dying neon tetras
Hi there,
<Hi there...this is Jorie, and I'll try to help...>
Have just come across your site and trawled it for any similar problems to mine, but couldn't spot anything, so I hope I'm not going to waste your time, but here goes!
<You certainly are not wasting anyone's time - we are here to help you!>
My fiancée and I purchased a 13 gallon tank about 3 weeks ago and set it up as follows: washed gravel in water till it ran clear, washed resin tank ornaments in the same way. A couple of plastic plants, but mostly real plants (some sword grass and sword plants, at least that's what they said they were in the shop).  We added the tap water and treated it with AquaSafe to dechlorinate, etc. following the instructions on the bottle. We added some AquaPlus water conditioner and we also added a little plant food that said it was safe for other tank inhabitants and followed the instructions in both cases carefully. 
We have a mechanical, biological and chemical filter that we checked was the right size for the tank, and a heater that keeps the water at a constant 78 degrees Fahrenheit.  The filter also has an attachment that can further oxygenate the water (little pipe attachment to pump out more bubbles).  Also have a hood and light for the tank.
We cycled the tank for these weeks, and before we put any fish in we checked the ammonia, nitrite, nitrate and pH levels: ammonia, nitrate, nitrate were 0 and pH at 7.5. We live in Glasgow in Scotland and our water is quite soft. We also added some AquaPlus water conditioner the morning before the fish went in, because it recommended doing so for new fish. We bought six jumbo neon tetras yesterday afternoon - floated the bag for half an hour to get the temperature even for them, added some tank water gradually over another half an hour and then released them. They looked pretty happy, we left the light off to let them settle down and didn't feed them straight away for the same reason, feeding them a tiny amount about 2 hours later.
Just before we went to bed we checked on them, and two seemed listless and gasping a little, but still able to swim, not just floating. This morning 2 were dead upside down on the tank bottom, and this afternoon two more. We did another water check and the levels were still fine. The poor guys looked physically ok when they died, apart from being a little pale - you could still make out the bright colours on their bodies. They didn't appear bloated with no cuts or gashes and seemingly normal gills. No signs of fungus or spotting either. When I was keeping an eye on the second two that died later, they seemed to get listless and were floating about the main body of the tank rather than swimming in the plants like the others. They also looked to be gasping a little.  
I really don't want to be doing something wrong and be unknowingly hurting the wee fellas. The last two seem ok at the moment, although one swims about more than the other.  Do you think it could be something they had already from the shop, or am I doing something terribly wrong? Do you think I need to get them some medication, only I am reluctant to do so when they don't look hurt or diseased and I might do more harm than good?
Any advise greatly appreciated, Charlotte
<Charlotte, I'll be honest, I'm a bit mystified myself as to what's going on! I read your thorough narrative above, and very honestly, you did absolutely everything I typically suggest to newcomers, from rinsing the gravel, cycling the water, keeping the temp. constant, etc. The one thing that I'd suggest you measure is the water's oxygen level; you mention that you do have an air filter in the tank, but the gasping behavior you've noticed makes me think perhaps they fish aren't getting enough O2. Most major test kit brands have a conversion chart to measure oxygen levels - I personally use the Tetra brand kit, but I don't think it matters too much. Just stay away from the "dip stick" type test kits, as they are pretty unreliable. Aside from that, I'm thinking perhaps a toxin other than ammonia, nitrite or nitrite has found its way into the water - I say this because of the suddenness of the fishes' death. Can you think of *anything* (from cleaning supplies to air fresheners, for example), that could possibly be contaminating the water? I don't know if it will help, but you could try additional water changes and perhaps looking into a PolyFilter - filter media that removes lots of unwanted toxins, from phosphates to ammonia. (That's a shot in the dark, though - it's all I can think of!)
You may be correct in thinking your fish weren't altogether healthy when you purchased them. Any idea how long they were living at the fish store? That's good question to ask - the longer the better, but you won't always get that lucky. I have never personally kept neon tetras, but from what I understand, they can be fragile. You did well to slowly acclimate them when you brought 'em home, and as I said above, did everything else according to the "rules". 
With regards to medicating, I don't think I'd go there, especially since you don't see any observable signs of illness or lacerations. You may indeed do more harm than good - I never recommend using meds just for the sake of it, and it's always best to narrow down what's going on before taking a "shot in the dark" approach to medicating fish.
Do check on the oxygen levels, and think about possible water contaminants. In the meantime, keep those water levels pristine, and hopefully the two survivors will be OK. I'll cross my fingers for you!  Good luck, Jorie> 

Re: Dying neon tetras
Hiya Jorie,
<Good morning, Charlotte.>
Thanks so much for your reply, I don't think they had been in the shop long now I think about it, because we had been in a couple of times in the days before to get fish food and other things, and hadn't noticed them when we had a look around.  I can't think of anything I might have accidentally exposed them to (even been careful not to wear perfume on my wrists in case I need to dive in!) but maybe I'm forgetting something. I'll definitely look into a PolyFilter, that sounds a good idea - want to do my best for them, felt awful for the first ones. Have named the other two Crusoe and Friday as they are so far survivors!
Thanks for all your advise, you've been really helpful, I'll keep you posted, but so far so good.  Charlotte 
<Glad to hear Crusoe and Friday are doing well! I know neon tetras are an extremely popular choice with hobbyists, but my understanding is that they are remarkably fragile. Additionally, I believe they are strictly wild-caught (as opposed to tank raised), which always increases the chances of a fish not acclimating well into captivity. It sounds as though you are doing absolutely everything you can to keep these little guys happy and healthy, so I wouldn't beat yourself up over it too much. Some things just aren't within our control! Best of luck, Jorie> 

Deformed Black Tetra
I have a black tetra who has black growths on it. It is several years old.  Its stripes have faded some, but these growths have shown up around its body, some around one gill and around its mouth. The upper part of its mouth has receded somewhat (looks a little like cancer there.) It is still hanging with the school and does not seemed to have slowed down. Do you have any idea what this might be? Thanks for any help.  Jeanne O'Keefe
<Mmm, most likely simply the effects of "old age"... cumulative developmental genetic defects... Perhaps Lymphocystis... Nothing to do. Bob Fenner> 

Rummy Nosed Tetra
Hi Crew - you've always been so helpful in the past - hoping you can do it again. I have a small school of Rummy Noses (7). I've just noticed that one of them looks like he/she has white masses under the skin of the abdomen. The others are all silver in the body - even transparent looking. This one looks like there's something white and opaque in the body. Could it be Neon Tetra Disease? Doesn't look lumpy or bloated. 
<Not likely NTD... perhaps another ailment>
I'm going to move it to another tank that has some Cory Cats, Flying Foxes, Platies and Guppy. If it's Neon Tetra Disease, will it infect these other fish?
Thanks so much!
<NTD can be very "spreading", but I strongly doubt that this problem is at play here. I agree with your speedy isolation of the one individual. Let us hope the "white masses" are passing. Bob Fenner> 

Diamond Tetra
Hey! Brody here again (a.k.a Frank Fish). I have two diamond tetras in my 50 gal. tank. I noticed a bulge in the abdomen of one of them about a week ago and I cannot figure out if it is constipated, gravid, or really sick.
<I hope the middle one>
I just checked my water parameters and they are fine (Ammonia 0; Nitrite 0; Nitrate 25ppm, pH 7.8, Hardness 160ppm). I have no idea how to sex tetras so I cannot tell if it is gravid, or even if it is a female and its partner is a male. I read on your site that brine shrimp helps with constipation and I bought some O.S.I. Brine Shrimp flake food and all my fish seem to love it. Think this could help?
<Yes>
Could it be Malawi Bloat?
<Doubtful... not common in S. American Characoids>
The tetra is eating well, swimming normally, behaving normally, etc...Any suggestions? Thank you very much for your time.
-Brody
<I'd keep mixing in (daily) some of the brine shrimp... maybe try adding a bit more greenery to their food as well... and if the swelling persists for more than a couple weeks, a teaspoon per ten gallons of Epsom Salt added to their water. Bob Fenner> 

Re: Diamond Tetra
Hello. I just e-mailed you about my Diamond Tetra about an hour ago. I went back and observed it for a while and I saw it occasionally kind of "wobble" from side to side. It would swim straight, then slow down, then its belly floated the fish up until it was vertical for a brief second and then the fish stabilized. I must stress that this behavior does not appear to be constant. Could this be swim bladder disease?
<Mmm, this is not really a "disease" per se, yet per accidens... that is to say, not the cause but a resultant symptom... The question is: what is at play here... or is there anything really at play at all?>
It does not seem to be having any trouble swimming at different levels in the tank as it is usually all over the place. And, as I mentioned earlier, it does appear to be eating well. Thank you very much for your time. -Brody
<I wouldn't worry, panic here... give all some time. Bob Fenner>

Cardinal problem
Date: Sun, 13 Mar 2005
Hey there, I was wondering if you'd be able to help me with something. I have had FW tanks for a long time but have not had any real luck with setting up a school of either neons or cardinals. My current "failure" is a discus planted tank. It is a 46 gallon bowfront tank with 6 discus and 3 clown loaches.
<Too crowded... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/discusfish.htm >
The water conditions are NO3 is 20ppm, NO2 is 0, hardness is 120, alkalinity is close to 0 and pH of 6.4ish. Temp is 85F. The discus are doing fine and I do daily water changes of 5-10 gallons using RO water mixed with 1/2 gallon of regular non-RO water (for the plants). 
<Good practice!>
Discus show no signs of stress and live normally. I brought home 11 cardinals about a week ago which I bought at a LFS. They all seemed fairly ok even though a lot of them had skinny stomachs (due to lack of food I'd guess).
<Yes, common>
I first placed them in a quarantine tank, losing about 4 in a few days. After 5 days, and the rest of the cardinals looking ok, I moved them to my discus tank hoping for some survival. few days later, I am looking at 3 fish left (which do eat) but are covered in ich.
<Yikes... should keep quarantined... for a few weeks>
none of the other fish show any kind of ich or other
diseases. The temp is high (for discus) and I was thinking ICH wouldn't live, but these cardinals are covered.
<Likely will die there>
I am at a loss here. Please help if you can see what I am doing wrong.
Thanks,
DK
(P.S. I'd even go to neons if that meant they would live better, but I read somewhere that cardinals take the high temp better.)
<This is correct... I would try again, with a new batch of Cardinals.... but quarantine them longer... slowly raise the water temperature (am sure the store did not have them in the 80's F) to the Discus water conditions, fatten them up first. Bob Fenner> 

Sick Tetras
I have a question regarding my neon tetras. I have a 25 gallon tank with a bio wheel and Eclipse filter. The ph is constant at 7, the temperature is constant at 80 and I do regular water changes (every 3-4 weeks as advised by our Aquarium store) and I treat the water with a Sera product called Aquatan before I add new water. I do not know the ammonia and nitrite amounts as I do not have a test kit for these yet. 
Our tank has been set up for 18 months and we have had no problems. We have 5 neon tetras, 5 lemon tetras, 2 Corydoras, 3 otos, and 3 blue German rams that replaced 3 swordfish (the children were upset about the whole eating of the young aspect). Today I notices a problem with our neons. They all seem to have ragged fins from a mild to severe degree, most have some sort of dark greenish/blackish patches on their sides, and one in particular is emaciated and a very dull colour. This one also seems to have pop eye (one other looks like he is developing it ) and at certain angles I can see a few white things attached to his eyes and head (only this one seems to have the white effect). 
Is this neon tetra disease? What else could it be? Will it affect the other fish? How should I treat it? The other fish seem fine although one or two of the lemon tetras seem to have a couple of slight ragged/split spots on their fins that I had put down to age or nipping by the male swordfish we had. 
Thank you for your time in answering this question as my daughter is very upset and I want to make sure I treat the tank expediently and appropriately. Lisa
< Forget testing for ammonia and nitrites and get a nitrate test kit. Changing the water every three to four weeks may not be enough and may need to changed more often. I would recommend a 30% water change while vacuuming the gravel and then clean the filter. Now that the tank is clean you should see some improvement. The tail/fin rot may need to be treated if it gets worse with Nitrofurazone. The Popeye is an internal bacterial infection that needs to be treated with Metronidazole. After treating your bacteria that breaks down the fish waste may be gone so I would add some Bio-Spira to recycle the tank.-Chuck>

Sick Tetras II
Thanks for your quick reply. I wanted to follow up and let you know some more information that I got today. I took the neon tetras on a little trip back to the Aquarium shop (Aquariums West in Vancouver) and the staff were baffled by the greeny black patches. They agreed they looked sick but had seen nothing like it and said it was not tail rot. 
They are going to keep them in isolation for a few days and have a couple of other fish experts take a look. It likely will not help the fish but I want to know if it will spread to the other fish and they are very curious. I had our water tested and the nitrates and ammonia were both zero so I don't think the water is a problem (I do change the filter every time I do a water change). I will let you know if they come up with a interesting diagnoses.
Thanks again for your answer and your informative website, Lisa
< Diagnoses is always difficult when you cannot see the animal. Hope they are able to help. -Chuck>