Glowlight tetra... hlth., English    7/16/07
hi there hope you can help, I have a 75 gallon tropical freshwater setup with gravel substrate bog wood pieces and a nice dense selection of plants, I have 6 Neons, 6 Glowlight tetras, 6 Rummynose tetras and one bamboo shrimp, all water tests are fine and I cycled tank with no fish but with some mature gravel for 6 weeks, anyway one of my recent additions is the glowlites but one is very bloated since I bought him/her, seems to ok as swimming ok and interacting with other fish. do you think she maybe pregnant or is this some form of disease that needs treating? any help in this matter would be greatly appreciated, thanks Mickey
<Hello Mickey. A nice collection of fish and a good sized aquarium for them! Glowlight Tetras are egg-layers, so the female doesn't get "pregnant" as such, though female fishes of most kinds look swollen when they are full of eggs and ready to spawn. That said, this usually only lasts a couple of days, and it is usually obvious she is ready to spawn because the male fish will be following her about all the time. What is more likely is that she has some sort of sickness. Dropsy is the worst option. This is a symptom (accumulation of fluids in the body cavity) caused by a variety of generally untreatable diseases. A tell-tale sign of dropsy is that often the scales bristle out from the body, so when looked at from above the fish looks like a pine cone. Not much can be done about dropsy, particularly in small fish, and destroying the fish painlessly is generally the best thing to do. It isn't particularly contagious, but the things that caused the dropsy, such as poor water quality, can of course cause the problem to occur in another fish. That said, a dozen tetras in a 75 gallon tank are unlikely to be causing water quality problems. If your nitrite, pH, and hardness tests all look good, then I'd be tempted to write-off the Glowlight Tetra as simply a specimen that was probably sick when you bought it. Constipation can also cause swelling in fish, though typically in herbivorous species like Goldfish. Glowlight Tetras are largely carnivores feeding on insect larvae so don't need the same amount of fibre in their diet. A few meals per week of algae flake instead of regular flake is an excellent idea though just to be on the safe side. A long-shot is Neon Tetra Disease (NTD). This could potentially infect a Glowlight Tetra since they're quite closely related. NTD is basically untreatable though some commercial medications purport to offer a treatment when used early on. Regardless, NTD is highly contagious and sick fish should be removed (and probably destroyed) at the first sign of trouble. The classic symptoms of NTD are loss of colour, lethargy, and a tendency for the fish to leave the school and hide in shady corners of the tank. Just as some "meta-advice", because tetras are small and largely collected from the wild, they don't travel well or keep well in overcrowded tanks at the wholesaler and retailer. Often they have gone without proper food for many days, if not weeks, for certain parts of the trip. Being so small, their reserves are slight and mortality is quite high. When buying tetras, it is not uncommon to lose one or two within the first few weeks, and then everything settles down and the rest last for years. So even if you lose this one fish, do not be too alarmed, and focus instead on making sure the aquarium is clean and the water quality/chemistry correct for the species you are keeping. Cheers, Neale>

Re: Glowlight tetra – 07/18/07
Hi Neale thanks for your reply it was very interesting, as for my bloated Glowlight its still looking bloated but swimming and eating ok and joining in with community life, I understand the casualty thing but the scales aren't sticking out at all. I only bought the glowlights on Saturday would this be sufficient time to lay eggs if any were present if so I think maybe I should take your advice and write this one off sadly to a sick fish when supplied. I also recently bought a scribble plec and what I think is a bamboo shrimp which really freaked me out on the third day of it being in my tank, I awoke to find what I thought to be "chip's" dead body on the bottom of my tank Eeek!! so netted it out and done the old flush, only to discover two days later when I was sat watching TV who comes walking out of my plants but old "chip" turns out they shed there skin!!! anyway he's such a dude he looks great now real bright vibrant colours; cream stripe down whole of body and sort of red/brown horizontal wiggles on his sides and quite a red tail, do you think he is a bamboo shrimp??? I know without a picture it is very difficult to know. many thanks
<Greetings. Unlikely to be eggs. Breeding glowlights is difficult, and to get them "in condition" for spawning takes time and the right foods. Unlikely to happen in an aquarium shop. In the meantime watch and observe, and I'd recommend adding some anti-bacterial medication as well. Ask your retailer for what's on offer in your area. Early stages of dropsy can (sometimes) be cured by things like Furanol. Scribbled Plec is Hypancistrus sp. or L66. Like other Hypancistrus it's only "half hardy" so treat it gently. It won't do well in strongly alkaline conditions (ideally, you need pH 6-7 and low hardness). It also likes a fair amount of warmth, something slightly around 26-28C, in keeping with most other fishes from the Rio Xingu. On the other hand, it is very sensitive to poor water quality and low oxygen concentration. As for the shrimp, that sounds exactly like a Bamboo shrimp (Atyopsis sp.). Nice animals. Not hardy, but with good care easy enough to keep. Harmless filter feeders, despite their size. Since you can't filter feed these animals easily, be sure to offer it plenty of suitable food. Algae wafers, plec pellets, and other plant-based foods are ideal. Cheers, Neale>
 

Sick Glowlight Tetra? 7/9/07 Hello. <Hi there> One of my glowlight tetras seems to have a swimming problem. He's been swimming in place at a 45 degree angle with the tail fin pointing downward. He'll still swim up to the surface when it's feeding time, but usually he stays about 6" from the water surface in one spot. He has just recently developed this problem and I have not been able to find any definite answers on the wet web media site. Could it be a swim bladder problem or some sort of disease? If it is a disease, could the other fish in my tank "catch" it? <Is very likely an internal bacterial complaint... the thinness, bent-spine..., and yes, can be very "catching"... I do hope I won't appear too brusque, cruel, but I would sacrifice this animal... Place it in a small amount of water in a plastic bag and freeze it...> Tank info: 55 gal freshwater community tank 10 platies 6 bleeding heart tetras 3 glowlight tetras 1 x-ray tetra 3 Cory cats 2 zebra danios Temp: 74 F pH: 7.8 NO2-: 0 ppm NO3-: 5 ppm NH3/NH4+: 0 ppm I do about a 15% water change every 7 - 10 days and treat with AmQuel+. Attached is a picture showing the fish in question. Note his relative vertical position with the horizontal platy also in the pic. Thanks, Aaron <Should this fish die, dissolve... this problem could spread. There are "key diagnostic tools and indications" that point elsewhere, but precious little time here, and no economic means of doing much else. Bob Fenner> Re: Sick Glowlight Tetra? 7/9/07 Thank you for the quick response. I'll be sure to euthanize the fish as humanely as possible. <This is what I would do> On another note, is this condition a result of something I'm doing wrong with either water conditions or feeding? <Mmm, no... not only are these situations idiopathic, the fact that the other fishes you list are symptom free indicates that there is not some common-impinging factor here> I feed the fish tetra flakes every morning, sometimes substituting with freeze-dried blood worms. Is there a way to prevent such problems? -Aaron <Mmm, no my friend... None that I'm aware of. Picking out apparently "good" livestock, providing adequate environment and nutrition, reducing the chances of introduction of pathogens, insults... is about all one can do. Bob Fenner>

Poorly Glowlight Tetra  7/5/07
Hi,
<Ave,>
I've got a 30 Gallon tank and I'm a total novice. You'll have to bear with me because I don't know much about the real names of fish so I'll just tell you as best I can.
<OK. But a recommendation: go buy or borrow an aquarium book. Very useful.>
I have 7 Neon Tetras, 7 Glowlight Tetras, 5 Black Neon Tetras, 1 Male Siamese Fighting Fish, 1 Tiger Barb and 2 other fish that I can't remember the name of but I know it's got the word bubble in it!
<ONE TIGER BARB!!!! Tiger barbs are intensely sociable fish. They need to be 6 or more to be happy. An unhappy tiger barb is something you don't want -- they are terrible fin-nippers, and as sure as God made little green apples will soon shred your Siamese fighting fish's fins down to nothing. If you want a solitary barb, choose something like the cherry barb, which is territorial and does best either alone or in groups in a big tank. They're actually good fun in groups, chasing one another about. But one is fun, too.>
The reason I'm e-mailing you is that I've just introduced the Siamese Fighting Fish yesterday, and today I've noticed that 1 of my Glowlight Tetra's (which have been fine for ages) is swimming on its side but is swimming happily it seems, it isn't listless or on the bottom or top of the tank. It's swimming with the others.
<Possibly constipation, if the fish is otherwise healthy. Check the diet. Standard flake is fine for a while, but it lacks fibre. Crushed tinned peas and bits of cooked spinach or Sushi Nori are good green foods for small fish. Also try live daphnia and brine shrimp. Anything to get the digestive system working.>
It also seems to have scales missing on 1 side from what I can see. Apart from swimming on it's side and the scales missing, it's not gasping or swimming erratically or anything. I don't seem to see any symptoms of disease other than the swimming on the side and the scales missing.
<Missing scales are worrying. I wonder if it has been harassed by something. Siamese fighters are sometimes aggressive though not usually to tetras. Tiger barbs can be nippy, as mentioned. One other thought is physical damage, for example swimming into a filter or clumsy netting by you or the retailer when catching the fish. Either way, it's a good idea to treat with anti-fungus/anti-finrot just to nip any potential problems in the bud.>
I really can't tell what's wrong with him but I'm panicking in case it's a disease and all my fish will die!
<Doesn't sound "catchy". Treat as recommended, and observe for other symptoms.>
I don't know if the Siamese Fighting Fish has got anything to do with it, but the pet store I got him from assures me that he is perfectly healthy and he isn't attacking the fish at all he seems to be having fun on his own....?
<Entirely possible he'll be fine in your tank. Siamese fighters are usually at the receiving end of trouble in community tanks though. They find it very difficult to swim because of their abnormal fins. This makes it difficult to feed and to swim away from trouble. Many fans of Siamese fighters simply recommend keeping them "in solitary" all the time. I'm not quite that extreme, but do watch things carefully.>
I really don't know what to do. I haven't had my water tested as I don't have a kit as yet but I will get one straight away. I've been doing water changes weekly (about 25%) and I've been adding a weekly cleaner that I bought from a pet store. I doesn't actually have a name, it just says weekly cleaner on the bottle and I've also been adding a chlorine control when I do a water change. I add these chemicals on the advice of the pet store but I'm starting to doubt their advice as last time I visited the store 2 of their tanks had dead fish in which I had to tell them about!
<Firstly, get a water test kit. If you're on a budget I recommend the dip strips. They aren't especially accurate perhaps, but they are cheap and easy to use. Each strip comes with nitrite, nitrate, ammonia, pH, and hardness indicators, which covers all the basic things you need. I cut the strips longitudinally, so get 2-for-1. Since a pack costs about £10 and contains 20 strips, that's 40 tests altogether at 25p a throw. Doing bigger water changes will do no harm; 50% a week costs nothing more in time and effort and doubles the positive impact of each water change on your fish! I have no idea what "weekly cleaner" is but it sounds like rubbish. The only thing you normally need to add to the tank weekly is dechlorinator, and that is added to the water before its put into the tank. Plant fertiliser is another thing, but it's optional. Otherwise, everything else is either more or less useless (tonic salt for example) or only to be used in certain situations (such as pH buffer). Pet shops want you to buy stuff you add weekly because its profitable for them. As well as providing a service, they are in business, so you can't blame them. But you can be a bit more discerning in what you buy. Some things, like bigger fish tanks and better quality filter media *do* make a difference and are worth spending the money on. But other things are often just nonsense.>
HELP!
Sam
<Hope this helps, Neale>
 

Parasitized Metynnis - 06/27/07 Hello, Wet Ones! <In England, "Wet Ones" are moist towel things used to wipe babies' bottoms when changing their nappies (diapers). So, not normally something you call someone.> I have a silver dollar, Metynnis argenteus, that I think is parasitized. He was in quarantine (30 gal w/ air stones and Whisper III OTB filter) for 2 months, along with several rainbows, some hatchet fish, and some neon tetras. All appeared well in quarantine. We moved these fish to our 150 gal show tank about 4 weeks ago. After about 3 days we lost one of the hatchet fish to causes unknown. Four days ago we noticed a whitish spot on the side of the silver dollar and a similar one on one of the hatchets. The hatchet passed the next day. The silver dollar is still feeding well and swimming just fine! The white spot is diminished, but this dark spot just showed up. I've included three pictures. What is it!!! <Well, I can't see anything particularly worrying in the photo. Treating the tank with anti-whitespot would probably be wise though, just in case. Hatchetfish are uncommonly sensitive fish, especially when recently imported. Once settled, they become a bit more robust, but the smaller species (Carnegiella spp.) never really become "hardy". Do bear in mind hatchets seem to need a lot of food to stay healthy, while silver dollars require at least some greens in their diet. Observing these two guidelines should help in the long term.> Branon <Cheers, Neale>

Neon Tetra with mouth stuck open.   6/21/07
Hi All,
> I'm Fran and this question really does what it says on the tin. We have a neon tetra who appears to have his mouth wedged open. He sort of inhales smaller food particles so he's not starving, but it looks painful. My other half reckons it's just because he's old, and he does not seem the type of fish to leap about and injure himself, but I do not know what else could have done this and what I can do to help him. Many thanks on behalf of myself and Tetra, F.
<Hello Fran. This does sometimes happen, and usually when I've seen this on tetras it is because of a congenital deformity. Sometimes larger fish, like cichlids, dislocate their jaws when fighting. But that's unlikely to be the problem here. I'm not sure how a neon might damage its jaw to this degree, at least, not without something obvious, like mouth fungus, setting in first. Since the fish is feeding and otherwise healthy, I wouldn't worry about it too much. FYI, neons should live for around 3-4 years in aquaria, if that helps you decide whether he's "old" or not. Cheers, Neale.>

Mouth disease on tetras  6/4/07
> Hi Guys,
<Hello.>
> I have a 80lt f/w tank with a few tetras, a bristle nose sucker fish, two clown loaches, some dwarf gourami’s and a couple of mollies.
<All sounds fine except the mollies probably want brackish water, not freshwater, and the clown loaches grow very big (admittedly slowly) and even a tank twice the size of yours will be too small for them in the long run.>
> Recently the tank started smelling like dirt and one of the tetras died with a white growth that looked like it had grown over its mouth.
<The white growth was almost certainly "mouth fungus", which is a bacterial infection almost always brought on by poor water quality.>
> We cleaned out the canister filter as it had started to become noisy due to a build up of gunk.
<OK. But cleaning a filter should not mean wiping out the bacteria in the filter media -- so only ever clean the media in buckets of aquarium water.>
> A week later another tetra was found with this growth.
<So, the problem wasn't fixed.>
> I removed the fish, did a 40% water change and started using a Aquarium Pharmaceuticals ‘Melafix’ of 10ml per day with a 30% water change every 7
> days as directed.
<Melafix will have no effect at all on mouth fungus. Melafix is the aquarium equivalent of antiseptic cream -- it helps keep cuts and wounds from being infected, but don't expect too much from it. Your need anti-mouth fungus (a.k.a. anti-Columnaris) medication.>
> This was about 2 weeks ago.
<Mollies are nitrate intolerant when kept in freshwater aquaria. If I had a penny for every molly that died from being kept in a freshwater rather than brackish water tank I'd be richer than Bill Gates. Needless to say, none of your other fish are salt-tolerant. Yet again, an example of choosing fish before researching them.>
> Since then two mollies have died, with no signs of disease and last week I noticed one of the gourami’s turned from a red color to black. We did a water change and soon after this it returned to its normal red color.
<Fish sometimes change colour when stressed, including by deteriorating conditions. It sounds as if you have water quality/chemistry issues.>
> Ph is about 7, at the start of the issues it was around 6.
<Mollies need a pH of AT LEAST 7.5. All your other fish want a pH around 6.5 to 7.0. Any time the pH of an aquarium drops from 7 to 6 quickly, it means you have major problems with the aquarium. We need more data here: what is the hardness? What is the pH/hardness of the water straight from the tap (faucet)? What are the nitrite or ammonia levels?>
> Do you have any ideas??
<Sounds to me as if your tank is inherently unstable. Likely a combination of acidification through decaying organic matter in the tank (overfeeding, under cleaning) and not enough buffering capacity in the water. Various solutions depending on the specific problems. But we need more data to pin down precisely the causes. In the meantime, reflect on the stocking density, your maintenance regime, what (if any) buffering exists in the aquarium.>
> Cheers and hello from Oz,
<Cheers, Neale>

Re: Mouth disease on tetras  6/4/07
> Thanks for the quick reply Neale.
<No problems.>
> I did have my students feeding the fish, and I did suspect they were over feeding. They backed off the feeding about a week ago. I've ordered an
> anti-mouth fungus too. I vacuum the gravel every 2 - 3 months should I increase this to monthly? I also do a water change of about 30% monthly.
<Cleaning the gravel is a function of how dirty it gets. In a regular community tank with small fishes, what you're doing is fine. In the tank with messy fishes and a lot of detritus in the gravel, step the cleaning up. When you siphon the water out during water changes, it's always a good idea to "hoover" the gravel as well, and suck up faeces, decaying plant material, uneaten food, etc.>
> Can you please explain buffering capacity?
<Very simply, buffering is the ability water has to resist chemical change thanks to the water containing certain dissolved chemicals. Not all chemicals are buffers though. Table salt NaCl (sold to aquarists as "tonic salt") has no buffering capacity at all. It is essentially things like calcium carbonate (lime) that buffers water to an alkaline pH, or organic acids (commonly from peat) that buffer water to an acidic pH. Typically, aquarists buffer to a slightly alkaline pH because this works well for the widest variety of fishes while remaining chemically quite stable. Acidic pH systems tend to be unstable, becoming increasingly acidic over time unless carefully monitored. Anyway, provided you have a "medium hardness" on whatever hardness scale your test kits measure (say, 10-15 degrees General Hardness) you don't need to worry about buffering. It'll all happen in the background, and regular water changes will top up the buffering capacity of the aquarium without any further work from you. If the hardness is lower than this, i.e., you have soft water, then you may need to do some work. There are multiple solutions. You could keep brackish or hard water fish, for example. By adding marine salt to a brackish water system, or Malawi/Tanganyikan salts to a livebearer or African cichlid system, the buffering would again happen in the background all by itself. If you have soft water and want to stick with the soft water fish, such as neons, barbs, Corydoras, etc., you need to monitor the pH on a weekly basis until you get a feel for the trend in pH changes that happen in your tank. Large water changes weekly should prevent drastic pH swings. There are pH 6.5 buffering solutions available. You simply add them to the water with each water change. Alternatively, you could do what I do with my soft water tanks, and that is mix 1 to 3 parts soft water to 1 part hard water. Most good freshwater aquarium books should go into the water chemistry issues in depth.>
> Cheers and thank you for your advice.
> Mike
<Hope this helps. Neale>

I am obsessed with keeping freshwater cardinals! I just can't keep them alive!   5/13/07
Hi!
<Hello!>
Hope all is well with you.  I have a question I hope you can help me with. I have had reef and saltwater tanks for a couple of decades, and I do pretty well. I even have a 600 gallon one in my kitchen wall!
<Sounds nice. Though if you prepare sushi in the kitchen, I imagine the fish get rather nervous wondering if they're next...>
But I am obsessed with keeping freshwater cardinals! I just can't keep them alive!
<I we talking those neon tetra look-alikes, Cheirodon axelrodi, or the freshwater examples of the marine cardinals such as Glossamia aprion, the "mouth almighty"? I assume the tetras.>
I have a 45 gallon tank with a sump. (an old reef tank). I had it setup with a BioWheel, and gravel on the bottom. I suctioned the gravel monthly, did a 33% water change monthly, and no luck with the cardinals.
<Cardinal tetras can be tricky for a variety of reasons, but once settled in they're basically tough little fish. The main problem in my experience is Neon Tetra Disease (NTD), which works its way through cardinal tetras at about 50% mortality, i.e., if you buy 20 cardinals, and you get the dreaded NTD, you can lose up to half of them. Better than neons, where you lose all of them, but still annoying. Another issue with cardinals is they are all wild-caught. In fact, they're the most numerous exported tropical fish from South America. Anyway, by the time they reach the market countries around the world, they might not have eaten for weeks. My guess is that healthy, well-fed cardinals are more or less NTD resistant, but when weakened and cooped up in a retailer's aquarium, they are far more susceptible to this disease. So as with any wild-caught fish, buying when a new batch arrives can make sense, and then quarantining and feeding on a variety of live/frozen foods makes all the difference.>
I then added an undergravel filter (I know....dumb idea, but I was desperate!)
<There's nothing intrinsically wrong with UG filters. They do a good job of maintaining water quality. The problem with UG filters is their incompatibility with aquascaping and rooted species of plants more than anything else.>
No luck. Nitrates off the chart. Dead cardinals.
<Odd, given how small cardinals are. They don't eat much (and don't need to eat much, either). They're classic "pinch of flake a day" fish in my book. When you say "off the scale" you mean above 100 mg/l? What is the nitrate level of the water out the tap/faucet? I have to confess to keeping mine in rainwater with a bit of tapwater added. Seems to work well.>
Someone suggested bioballs.  Would not that make the nitrates even higher?
<Worth trying I suppose but I don't find nitrate removal systems in freshwater tanks to be of much value. Freshwater fish don't care that much provided the rise in nitrates is slow, and even between 50-100 mg/l you shouldn't get mass die-offs of fish except with certain species (Tanganyikans for example). Simple water changes are, IMO, a better approach to nitrate management, and the filter is best devoted to biological filtration, i.e., ammonia/nitrite management rather than nitrate.>
I have used Amazon rain additive (is that stuff any good?)
<Not really. Looks nice, but doesn't really do anything if you have hard, alkaline water. In softer water, may help acidify the water a little, but approach the concept of acidifying water with caution, as it's easy to mess up.>
No luck. PLEASE do you have an ideas?  Thanks!
<Have a read of this: http://www.wetwebmedia.com/ca/volume_2/cav2i3/cardinal_tetras/Cardinal_Tetras.htm for some more ideas.>
Ron
<Cheers, Neale>

Molly and Neon Tetra Health Questions, env.  3/16/2007
Dear WWM crew,
<Ching>
I love your website and learn a lot from here. Thank you.
<Welcome>
I have a 15 gallon tank with 2 Cory catfish, 3 black mollies and 7 neon tetras.
<Mmm... the Cats and Neons like very different water conditions than the mollies... soft, acidic, much warmer... no salt...>
Environment:
Water PH: 8.0 (Our tap water is pretty hard.)
<I'll say! About the same here in San Diego>
Temperature: 25~26 C
Nitrate: 20~40 ppm
<Way too high... a source of stress...>
Nitrite: 0 ppm
Ammonia: 0 ppm
One male molly has "obvious" mouth fungus and noticeable grey spots on his body. As I heard Cory catfish and neon tetra do not like salt, I did not add aquarium salt to the tank.
<Good>
I used Melafix and Pimafix together to treat the black molly. The second day and third day I could see the improvements and thought the medicine worked great.
<Mmmm>
As the medicine indicated we can use it when intruding new fish to the tank, so while during the course of Molly's medication (on the fourth day, I think) I added 4 neon tetras to the tank. The 7 neon tetra were doing fine and schooling around together. The black molly seemed to be getting better too. However, yesterday (the 8th day of the medication) black molly's mouth started to show the fungus again and I saw a couple of grey spots on his body. Should I use other medicine, stronger one? Or I should continue the ones I am using?
<I would separate the molly/mollies, treat it/them with salt... Keep it in another setting>
Today (the 9th day) I saw a red spot on one neon tetra's body, which is near the tail. I am not sure what it is an have no idea what I should do. It looks like human's bruise just the color is red not purple. Anything you could suggest?
<Yes... to modify their water chemistry (w/o the Mollies present)... to be softer/more acidic (pH below 7.0)...>
I have had this tank just for two months and enjoyed it a lot. But, there's still so much to learn to keep my fish healthy.
<Lots of valuable lessons about life...>
Thank you again for all the information you provide on the site. It is really helpful!
Yours truly,
Ching
<A pleasure to help you, Bob Fenner>

Death of our white-tipped tetra - overfed?   3/14/07
Hi,
<Hello there>
Thanks for such an informative and interesting site.
<Welcome>
Me and my boyfriend are reasonably new to the fish keeping game and sadly we've just experienced our first fish death. I'm really writing for some advice so that hopefully we can avoid any too many more in the future.
<Sounds good>
We have a 112 litre tank (just under 30 US gallons according to the online converter). We've had the tank since January and we cycled it for 3 weeks before adding fish (we have a very good LFS who wouldn't let us buy fish until we provided them with a water sample from our cycled tank!!!).
<Good for them, you, the planet>
Water parameters were fine when we tested on Saturday (nitrite and ammonia 0, nitrate 12mg/L, ph  8).
<Yikes... this last is quite high... particularly for small S. American Tetras...>
Sorry - not sure how parts per gallon work but 12mg/L is reasonably low.
<Parts per million and milligrams per liter are equivalents... the same... Think about this... there are a million milligrams or water...>
The tank is filtered, heated (around 76 F) and planted (grasses, a couple of broad leaf plants and some floating plants).
We have:
3 bamboo shrimp
5 white-tipped tetras (was six)
4 Corys
1 whip-tail catfish
2 thick-lipped gouramis (male/female pair)
<Sounds very nice... but do watch those Gouramis>
Yesterday I did a 20% water change (tap water with dechlorinator added - roughly same temperature as tank water). Everyone seemed fine. A few hours later we feed them frozen bloodworm. We tend to do this once a  week - usually at the weekend when we can watch them going nuts over them! Again, everyone seemed fine. We first noticed things weren't right a few hours later when the male gourami charged at one of the tetras (I know gouramis can be territorial but this was a major shock as we have the most chilled out and friendly gourami).
<At times...>
On closer inspection I think it was because the tetra was behaving oddly - floating at the top of the tank and spasming. The gourami didn't do him any damage, I think he was just curious. The tetra couldn't swim against the flow of the water and when he did try to swim he was spasming quite violently. He was looking swollen but other than that not a mark on him. He found a quiet place behind the filter and stayed there for an hour or so. Then he seemed to perk up a bit and went for a little swim. He was gasping for air though. He then went and sat at the bottom of the tank and after a few hours he died.  
We scooped him out and my boyfriend gave him a close inspection - not a mark on him.
The tetra looked very swollen so perhaps we overfed him. He was absolutely fine in the morning and acting as normal so it was a very sudden deterioration. We didn't feed any more bloodworm than normal but he was our smallest tetra by quite a margin and so perhaps he ate more than his share??
Does this sound possible?
<Is, yes>
I've read that bloodworm can be hard to digest - is this a big problem?
<Can be for small fishes, yes>
The other tetras didn't look swollen at all and were swimming around fine.
We've had the tetras since the end of January and the last addition to the tank, the Corys, we have had for 3 weeks now. Could it be an infection and would you advise any action?
<Not likely an infection... I would not "treat" here... more likely to cause harm than help>
I can't help thinking we've overfed him, which makes me really sad. He looked swollen and uncomfortable and it all happened so quickly that I'm sure it must  have been something that day - the food or the water change.
<These could both contribute...>
Much appreciate any guidance you can give. Sorry for the mix of volume units - I'm British but thought you'd appreciate US measures where I could do them.
Thanks
Naomi
<No worries... A third possibility is that this one fish had a sort of genetic/developmental disorder... Fishes aren't "quite developed" even at good size... Bob Fenner>

Seemingly Incurable Mouth Fungus   3/11/07
Hello,
  <Hi there Theresa>
  I was hoping to find some advice to treat an apparent case of mouth fungus on one of my neon tetras.  My tank is 30 gals with a 7" pleco, 2 serpae tetras, 2 emerald eye tetras, 3 high fin black tetras and 5 neons.
<Mmm, with such a nice mix, I do hope your water quality sides on the warmer, more soft and acidic side>
About three weeks ago, one of my neons developed what I think is mouth fungus on one side of his mouth.
<Mmm, actually funguses are rare... more likely bacterial in nature, and resultant (if only one specimen afflicted) from a physical trauma...>
I treated it with MelaFix
<Worthless>
as per the instructions removed carbon and daily treatment for 7 days (I can tell from your site MelaFix is not one of your favourites!)
<For me, you are correct>
  No results,  so I treated once again after a 7 gal water change.  I still had no improvement in this fish but no other fish seemed to get sick.  I know (also from your site) that I should have a quarantine tank but unfortunately space does not allow for me to have 2 tanks!  I spoke with my LFS and they recommended the Maracyn.
<I do as well.... Erythromycin otherwise known as>
I have treated twice with this medicine over the period of about 2 weeks and still no improvement.  I have now noticed that one other neon has a small white spot near his
mouth.  Is there another medicine or technique that you could suggest?
<Mmm... the next most likely effective, and safe... Maracyn II, Minocycline>
Along with the Maracyn, the LFS recommended that i raise the temp in the tank (it is now about 80)
<I also agree here>
and I also added some salt
<Mmm, no... Definitely not. None of the fish species you list has much tolerance for this>
which I was unaware was needed in a freshwater tank.  I am not sure what to do next so I was hoping for some insight from your website.   
  Thanks in advance for your help in this matter.  I know these are only neons and I would really like to see them get better but I don't want to lose my tank population either.   
  Theresa
<Do raise the temperature, to the mid eighties F., and try the Maracyn II... Bob Fenner>

Re: Seemingly Incurable Mouth Fungus II   3/11/07
Thank you for the info and most of all the quick response!
<<Bob answered your original query…a "you're welcome" on his behalf. Lisa Brown here.>>
It is greatly appreciated by me and the tank.  I have started to raise the temperature to the mid80s and I am now on my way to try and find the Maracyn II.  I really hope this will save the affected fish.  
<<Likely will.  Be sure to keep pristine water conditions as well.>>   
Just a few more questions - should I do a water change before I begin the next treatment and if I cannot find the Maracyn II should I try another treatment with the regular Maracyn?
<<Yes to the water change (~25%).  You should have no trouble finding Maracyn II. Either at your LFS, or online from a number of vendors.>>
Thanks again,
Theresa
<<Glad to help Theresa. Lisa Brown.>>

Re: Seemingly Incurable Mouth Fungus II  – 03/15/07
So, I am on the 4th of the 5th day of treatment with the Maracyn II and there is no improvement in the fish.  My water has become quite cloudy (I did remove the carbon prior to the treatment) and it seems to have a yellowish tinge for some reason.
<Medication effects>
One of the other neons has a small spot on its mouth also.  I did a few tests on the water quality and the ph is about 7.2 and it tested as being on the hard side.   
  Do you have any more advice for me as I am not sure where to go from here?
<A microscope, reference works...>
Do a water change and start another treatment with something else or should I keep with the Maracyn II as the fish has been sick for awhile and maybe it will take 2 treatments?  As you can tell I am grasping at straws!   
  Thanks again.
  Theresa
<I would continue to monitor water quality... finish the Antibiotic treatments... and read. Bob Fenner>

My Tetra's mouth has moved   3/11/07
I have a 10 gal tank with 3 black skirt tetras 1 white skirt and an Otocinclus. The white skirt is the oldest member and her mouth seems to have moved from the point of her face up her face toward the top of her head. The bottom Jaw flesh seems to have gotten bigger and the top lip receded so that it looks like she cannot really close her mouth totally. I suspected maybe mouth rot, but there is no white fuzz on her.
<Mmm... much more likely "something" developmental (like acromegaly in humans) or resultant from an injury (jumping...)>
I had one other white skirt go this way until he started swimming on his side in vertical circles and doing stupid stuff so I euthanized him. Any ideas what I am dealing with? Could it just be an old age issue?
<Yes>
Her right eye seems to have eye pop also, but her left one is okay.
I have been changing the water weekly, but the water temp is a little high due to treatment for suspected ich.
<Mmm, not likely too high... can tolerate temperatures into the low nineties F.>
Any suggestions would be appreciated.
Thanks
<What is your water quality overall? Hardness, pH... do you have appreciable nitrate? Bob Fenner>

Re: My Tetra's mouth has moved (follow-up)  - 3/12/07
<<Hello. Tom covering for Bob this time.>>
Water quality:  Nitrites 0, ammonia 0. Don't have hardness or nitrate tester. But this may be an issue, my pH reads 7.6 but this is the max the tester will register so it may be higher. Could this be the issue?
<<Not “the” issue, as such, but could definitely be “an” issue, as you suggest. A high pH level isn’t the problem it was once seen to be as long as it remains stable. Fish acclimate to pH ranges outside of the “ideal” quite readily, for the most part, and the consensus is that it’s better to keep our fish in water that’s readily available from the tap rather than “toying” with it where pH is concerned. Bob’s reference to water hardness was meant to get a sense of the buffering capability of your water, i.e. the ability of the water to resist changes in pH. The higher the buffering capacity, the less likely you will experience a dangerous, potentially catastrophic, drop in pH. To address your question more specifically, White Skirt Tetras have a pretty wide pH-tolerance range with the high end being around 8.5. There aren’t many fish in the freshwater arena that “prefer” pH levels this high even among the Cichlids, which are known for thriving in alkaline water.>>
How do I lower it on a permanent basis?  
<<Rather than saying you can’t, I’d prefer to tell you not to try. First, it may be totally unnecessary and, second, you may be setting yourself up for problems. The saltwater folks have a leg up on most of us FW hobbyists as there are substrate materials, aragonite in particular, that constantly provide calcium carbonate (among other trace elements) to the water, raising pH to levels their aquariums require on what might be deemed a “permanent” basis. Lowering pH is more problematic and, unfortunately, temporary over the long haul. Just not a good idea with play with it.>>
I will try to get the other testers but we live in a small community and may not be able to quickly.
<<As you’ve probably surmised, I don’t think this is necessarily an urgent matter but I agree that it’s one that should be looked into soon. You need to have a feel for the buffering capacity of your water to ensure there are no sudden plunges in your pH levels. If there’s an issue here, this is it in my opinion. My best to you. Tom>>

Fish can't swim, FW mysterious paralysis in Tetras  – 03/09/07
Hello, I am having an issue with the fish in one of my tanks everything water wise is fine (ammonia 0, nitrite 0, and nitrate 10) and it is a heavily planted tank. but a couple of the fish have died and a couple that are alive seem to have rigor mortis in their tails and can barely swim( they are couple of Rio von tetras and green flame tetra).
CJ
<Yikes... very strange... and no way to diagnose w/o much more information... I would do the S.O.P. in such anomalous cases, a good-sized water change (perhaps half) and addition of a chemical filtrant (likely activated carbon, or a product with a preponderance of such). Now! Bob Fenner>