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FAQs on Callichthyid Catfish Disease/Health 4

Related Articles: Callichthyid Catfishes, Summer loving: cats in the garden, kittens in the kitchen by Neale Monks,

Related Catfish FAQs: Callichthyid Cat Disease 1, Callichthyid Cat Disease 2, Callichthyid Cat Disease 3, Callichthyid Cat Disease 5, & Callichthyids 1, Callichthyids 2, Callichthyid Identification, Callichthyid Behavior, Callichthyid Compatibility, Callichthyid Selection, Callichthyid Systems, Callichthyid Feeding, Callichthyid Reproduction, Catfish: Identification, Behavior, Compatibility, Selection, Systems, Feeding, Disease, Reproduction,

Sick Corydoras sterbai; Costia treatment     1/21/19
Dear Crew,
<Hello Matt.>
Thank you for everything you do for the hobby!
<Kind words, indeed.>
I'm writing today about a sick Corydoras sterbai. Disease progression has been as follows:
(1) Some light gray spots visible against the brown coloration on the head, while that brown color became more of a muddy gray and the light spots/reticulations became indistinguishable from the background.
(2) Overall fish color gradually became lighter, with white along the flanks becoming more prominent than brown. This may be an extension of (1) but is also consistent with what seems to be stress coloration for the species.
(3) Although initially there was no apparent reduction in activity, the fish gradually became more lethargic. When my bossy Bristlenose Pleco nudged the sick Cory today, the Cory's usual swim-away response was considerably delayed, and it took more than one nudge. The Cory is not competing effectively for food with the Bristlenose or the other two Corydoras sterbai.
<Understood. Any evidence of Red Blotch Disease, such as the diagnostic red sores on the belly? This is quite common in catfish, especially if the bottom current along the floor of the tank isn't particularly strong and/or the substrate isn't too clean.>
I've seen the same progression with two other Corydoras sterbai in the same tank over the last year; neither survived. I've also lost two others to unknown causes during vacations. After reading about Costia on WWM, that's my best guess as to what's happening.
<Or Columnaris, which is another of these diseases that creates off-white or grey slime patches on the flanks. Columnaris is sometimes called Mouth Fungus but is by no means restricted to the mouth.>
This is a 20 gallon "tall" tank, with two hang-on-back filters (240 gph and 100 gph) and two air-driven sponge filters. Tank inhabitants are one common Bristlenose, three Corydoras sterbai, and 8-10 assassin snails, with one piece of Mopani wood, a couple of Anubias, and a large mass of Java moss.
Water is neutral, moderately soft, with one-eighth to one-quarter teaspoon baking soda added per 5 gallons. Temperature is 79 F/26 C. NH4 and NO2 test at 0, NO3 at 5 ppm (all per API liquid tests).
<All sounds fine, though Corydoras don't appreciate having to swim upwards 30 cm/12 inches, so a "tall" tank isn't usually optimal.>
I've moved the sick Cory to a 10 gallon hospital tank, with the 100 gph filter, one sponge filter, and a supplemental airstone. It's at 79 F/26 C now. Neale has mentioned that Costia has trouble surviving above 86 F/30 C, so I'm slowly raising it to that temperature, which C. sterbai can handle.
<Corydoras sterbai will be fine at this high temperature, but will gulp air more often.>
My question is: is there anything else I can do or should be doing?
<Do review the symptoms of Columnaris as well as Costia. Hard to tell them apart without a microscope. Costia is usually treated as per Whitespot, though it is more stubborn. Columnaris is treated as per Finrot, though again, can be stubborn.>
Of the other things I've seen suggested for Costia on WWM (saltwater dips, formalin, copper), none seems particularly "safe" for a Corydoras, but is one safer than the others? I'm in the U.S., so eSHa 2000 is not an option. I have Kordon Rid Ich Plus (formalin/malachite green) at hand.
<Avoid formalin and copper-based medications when treating catfish, but antibiotics should all be safe, and the usual organic dyes (such as malachite green and Methylene blue) should be okay, too.>
Again, thank you for your help.
<Good luck. Cheers, Neale.>
Re: Sick Corydoras sterbai; Costia treatment      1/22/19

Dear WWM,
I have a further question on my sick Corydoras sterbai with a suspected case of Costia. The fish has developed Popeye in both eyes. As suggested in Neale's article on salt and Epsom salt, I've added 4 teaspoons of Epsom salt to the 10 gallon hospital tank, which is now at 86 F/30 C.
<Should help. A rule of thumb is this: if one eye swollen, likely physical trauma, such as fighting or bumping into something; if both eyes, then more likely environmental and/or bacterial. Choose medication as indicated, though antibiotics, if used carefully, should cover both possibilities without causing harm.>
My further question (in addition to how to deal with the Costia) is whether to treat the Popeye with antibiotics, and if so with what.
<See above; almost impossible to say for sure the optimal antibiotic without identifying the bacteria (and/or having a biomedical degree) but the old Maracyn 1 and Maracyn 2 combo is widely used.>
The catch is that the fish is not eating. Nitrofurazone is often recommended for Popeye, and I have Hikari BiFuran. However, my impression is that nitrofurazone is not well absorbed through the skin, so for internal complaints, the only effective means of administration is via medicated food. Is this correct?
<Does tend to be true, yes.>
I also have Seachem KanaPlex (kanamycin), which is absorbed through the skin relatively well and which the manufacturer suggests for Popeye.
<Kanamycin is a good choice in such situations, yes.>
I haven't seen it recommended much for Popeye on WWM, and I'm wondering whether it's the best treatment under these circumstances (fish not eating) or whether another treatment/approach would be better.
<Kanamycin has a more limited range of applications than some of the other antibiotics, but it is well absorbed through the skin, so worth a shot.
Popeye often fixes itself under optimal conditions, so it may well be that just helping the fish's own immune system is all that's needed, rather than a complete cure.>
Again, thanks for everything you do for the hobby, and any suggestions would be much appreciated.
<Good luck, Neale.>
Re: Sick Corydoras sterbai; Costia treatment      1/22/19

Thank you for your helpful response.
<Most welcome.>
Sadly, the little fellow had given up the ghost by the time I got back from the aquarium store with the Maracyn One and Two. If nothing else, I'm better prepared for the next time.
<Sad outcome, but as you say, it's a learning experience you may be better prepared for in the future.>
Your comment about Corydoras doing better in shorter tanks is consistent with my experience.
<Ah, yes. In the wild they're among those fish found in streams where the water may be just a couple inches deep. Whether or not Corydoras need to gulp air is unclear to me, but in relatively warm home aquaria, it seems likely.>
Mine had far fewer problems when I had them in a 33 gallon "long." (That aquarium sprang a leak, and the 20 gallon "tall" was gathering dust in the garage, so I pressed it into service.)
I appreciate all the sound information and advice and have made a contribution to WWM via PayPal for beer, bandwidth or some combination of the two.
<Thank you for this.>
<Cheers, Neale.>
Re: Sick Corydoras sterbai; prob. Columnaris       1/23/19

About being prepared for next time... it's happening sooner than I expected. One of my remaining Corydoras is showing early signs of the same disease (fading of body color and a few light gray spots around the head).
<Oh dear.>
Thank you for your previous responses. On further reflection, I think my diagnosis of Costia was wrong, and your suggestion of Columnaris was correct, for the following reasons:
-- Light gray blotches were concentrated on the head and dorsal region rather than all over the body. Although I didn't see a well-defined "saddleback," the largest/strongest light spot was just ahead of the dorsal fin.
-- Raising the temperature to 86 F/30 C (on the belief it was Costia) seemed to accelerate disease progression rather than slow it down. My understanding is that Columnaris progresses more quickly at high temperature.
<Indeed; Columnaris is notoriously rapid, and can go from zero symptoms to a dead fish in days.>
To answer your question from before, I saw no red spots, on the belly or elsewhere.
From my reading, I understand that Flavobacterium columnare is a gram-negative, aerobic bacterium. My inclination is to move the fish to a hospital tank, reduce the temperature to 75 F/24 C, and treat with KanaPlex and perhaps nitrofurazone or Triple Sulfa. Does this make sense?
<Yes. I would treat all Corydoras together, to reduce the stress of isolation. Do bear in mind that with small fish treatment doesn't always help, and sometimes you end up with a batch of fish that 'fail to thrive' and have to wait a while, then buy a new, healthier batch.>
Also, would adding aquarium salt (purely as an adjunct, not as the main treatment) be beneficial?
<Unlikely, unless your water was abnormally soft. The idea of adding salt is to tone down the need for osmoregulation a bit, and reduce fluid loss, or something along those lines. In medium hardness water (or harder) the addition of salt doesn't really do anything useful, given Corydoras actually prefer soft water, and adapt (albeit successfully) to harder water conditions.>
Again, I greatly appreciate the help.
<Good luck, Neale.>

Corydoras panda whitens out      8/16/17
Good evening (here), WWM Crew, I hope you are having a good week. Kindly allow me to emphatically state that this hobby is so fantastically rewarding but so frustrating sometimes!!!
<Oh, I concur>
My tank specs are ammonia/nitrite zero, 15-gal column,
<Mmm; not the better shape for Corydoras..
. which are facultative aerial respirators (come to the surface to breathe)>
everyone looking great and getting along fine. I have three large C. metae and one small C. panda, along with my mid- and upper-dwellers... the corys get shrimp pellets at night, a few times per week.
<I'd feed these (diurnal) cats during lights-on time>
I try to never overfeed. This morning the panda Cory's off-white skin was bright white and he was buoyant but visibly lethargic. Worst part--I had to leave for vacation. I decided that perhaps the big boys were boxing him
out for food, so maybe he was malnutritioned. I did a 25% water change and then moved the panda Cory--he did not put up much of a fight--into a floating breeder and dropped two different brands of shrimp pellets in for him. I figured if he wasn't eating, then now was his chance, and although now isolated, his stress level would have been high, regardless.
I removed most of the pellets before I left, leaving some crumbs. This way (1) ammonia from decaying small crumbs, at the top of the tank, wouldn't be too awful for the water (correct?)
and (2) if he still didn't make it, his body wouldn't become a meal for others. How would you have handled this one?
<Moved the fish to a different, established set-up if I had one>
And if this little guy does make it, do you have any ideas regarding his survival besides moving him to a new tank?
<This is about it. How warm is your water?>

Ideas are more than appreciated!
<Welcome. Bob Fenner>
Fwd: Corydoras panda whitens out      8/16/17

I meant to attach this photo:
<As you stated, stressed... BobF>

Re: Corydoras panda whitens out       8/17/17
Thanks Bob. I have the tank at 74 degrees
<A good temp. for all>
and I did work hard to find larger corys when I got these C. metae fishes, in hopes their bigger fins could propel them more easily to the surface to gulp air. They playfully race up and down the sides so it doesn't seem like a problem for them. I don't recall reading on WWM that I should try feeding corys during the day, but I can give that a shot, then maybe I can make sure they get to the sinkers while the others eat at the surface.
I'll report back after my trip. Thank you!
<Thank you Matt. BobF>

Re: Corydoras panda whitens out      8/21/17
Hi Bob, just following up... the panda Cory did not make it although I'm happy with my decision to keep him in the breeder so his body was not a Gourami snack. I removed him and did a 25% w/c. I'm going to see if these three large C. metae will fit the bill in this column tank...
<I think they will admirably>
would you say, one shrimp pellet each, a few times per week?
If not, Neale suggested whiptail cats instead.
<Another good choice>
They are tough to find around here so may be pricey... do you think they will survive with (smooth) gravel substrate?
<Yes I do>
Thank you!
<Welcome. BobF>

Problem with Corydoras (Bob??)         4/5/16
Hello crew, as always, thanks for the help and all the good work.
<Thanks for the kind words.>
Im writing to you today because one of my Corydoras was gasping while on her side... It seemed to recover a few hours later but has now come back it. Tank is 3.5 months old, 150 gallon tank with ph 7.7, and 0, 0, 20 ppm in nitrogenous compounds.
<All sounds fine.>
I have had this Corydoras with me for about 2.5 years its my oldest Cory. there are 3 other in the tank ( same species). I cant avoid looking at her belly and think she's probably underfed.
<Would seem so; do feed, generously, at night if you have lots of nocturnal fish, and you do. Assuming a 5-6 Corydoras, 5-6 Kuhlis, and the Whiptail, I'd be adding one or two algae wafers 3-4 nights per week. Check in the morning if any food is leftover and adjust accordingly.>
I feed twice a day, in the morning for most of the fish and an hour after turning off lights for the Kuhlis, Corydoras, Otos and Rineloricaria parva. I also noticed today she seems like she broke her lateral fin spine? I have attached some pictures... She still swims but she's disoriented and hand feeding is not working.. :(
<I am not optimistic here. I do wonder if she has a Mycobacteria infection or similar, which can cause wasting, disorientation, and skeletal deformities. I'm cc'ing Bob Fenner to see if he can add anything more specific. You might also try asking at PlanetCatfish, an excellent website and forum specific to catfish, and there may well be people there who have seen this precise thing in Corydoras and know how to treat it.>
Thank you, for your time
<Welcome. Neale.>
Problem with Corydoras    /RMF          4/5/16

<8.7 megs of pix; why? >
Hello crew, as always, thanks for the help and all the good work.
Im writing to you today because one of my Corydoras was gasping while on her side... It seemed to recover a few hours later but has now come back it. Tank is 3.5 months old, 150 gallon tank with ph 7.7, and 0, 0, 20 ppm in nitrogenous compounds.
<pH is a bit high, but what stands out the most is that this fish's barbels are gone; worn away... Indicative of being placed on an improper substrate usually>
I have had this Corydoras with me for about 2.5 years its my oldest Cory. there are 3 other in the tank ( same species). I cant avoid looking at her belly and think she's probably underfed. I feed twice a day, in the morning for most of the fish and an hour after turning off lights for the Kuhlis, Corydoras, Otos and Rineloricaria parva.
<Okay; what are you feeding? Are you sure (apparently not) that this fish is getting sufficient nutrition?>
I also noticed today she seems like she broke her lateral fin spine?
I have attached some pictures... She still swims but she's disoriented and hand feeding is not working.. :(
Thank you, for your time
<The usual; sending you to read. Start here: http://www.wetwebmedia.com/fwsubwebindex/CoryDisF3.htm
and all the linked files above. Bob Fenner>


Re: Problem with Corydoras        4/6/16
Thank you, about the barbels, i got him like that from the beginning,
i have very fine volcanic gravel ( smooth) grain size is just a bit bigger than silica sand... Kuhlis and the other Corys have healthy barbels, as far as i can tell.
I am feeding a mix of tetra min tropical tablets and Spirulina tablets for bottom feeders... Eventually i drop some granules or grindal worms which go directly to the bottom... I really don't make sure everyone eats... I commonly just look at where i placed the food and i would see Kuhlis and Corys going about and assume everyone's fed.
<I wouldn't just assume. Do observe your livestock to assure they're getting enough to eat>
That black patch where the broken fin is a bacterial infection right?
<Likely so; yes>
I just cleaned the substrate. ( high tech planted tank i don't vacuum much but i realized the bottom was quite dirty) and made a 20% water change ( just did a 50% 4 days ago) i have moved the Cory to a 3 gal hospital, with tank water and a cycled sponge( have several lying in my tanks) still reading, deciding if go about using antibiotics.
<Thank you for sharing. Bob Fenner>
Re: Problem with Corydoras        4/6/16

Thank you, about the barbels, i got him like that from the beginning, i have very fine volcanic gravel ( smooth) grain size is just a bit bigger than silica sand... Kuhlis and the other Corys have healthy barbels, as far as i can tell.
<This is worrying. Not convinced volcanic gravel is smooth enough. Most of the traded stuff doesn't come from volcanoes, it comes from the glass making industry, and it's pretty sharp at the sort of scale we're worried about.>
I am feeding a mix of tetra min tropical tablets and Spirulina tablets for bottom feeders... Eventually i drop some granules or grindal worms which go directly to the bottom... I really don't make sure everyone eats... I commonly just look at where i placed the food and i would see Kuhlis and Corys going about and assume everyone's fed.
<Which is often fine and probably is if every catfish and loach is nice and healthy. But do review in this instance.>
That black patch where the broken fin is a bacterial infection right? I just cleaned the substrate. ( high tech planted tank i don't vacuum much but i realized the bottom was quite dirty) and made a 20% water change ( just did a 50% 4 days ago) i have moved the Cory to a 3 gal hospital, with tank water and a cycled sponge ( have several lying in my tanks) still reading, deciding if go about using antibiotics.
Thanks, Roberto
<I'm not wildly optimistic, but a robust course of antibiotics does look like the best possible chance of helping this Corydoras. Cheers, Neale.>

Sick Brochis     8/21/12
I have a Brochis splendens that is clearly not feeling well.
For the past 2 days, she remains at the bottom of the tank 50% of the time inverted, and for the past day with a curvature in the spine.
<This is out of the blue? Review possible sources of poisoning. Copper, formalin, chlorine, chloramine, etc. Because these are air-breathers, think also about anything sprayed or otherwise present in the air -- paint fumes for example.>
She changes positions every 2-3 hours.  On Sunday she looked as if she was standing on her tail-I didn't think much of that as my Brochis often configure themselves in odd positions. 
There are 9 Brochis total in the tank with rainbows (15) and giant danios (6) Otto's (7) and shrimp.
<Odd. Anything toxic to Corydoras and Brochis would surely affect shrimps and Otocinclus too.>
All inhabitants are long term, tank is well established, planted, and receives a minimum 50% weekly WC. Temp is 80 (higher than normal but it is summer),
<True, but unlike (most) Corydoras, Brochis tolerate warm water well.>
ammonia nitrite and nitrate are zero as  I have moved to daily Water changed to try to help her. I also have DIY CO2 disbursed via a powerhead.
<Disconnect the CO2 for the time being. Extreme swings in pH through CO2 fertilisation can cause problems, though there's the no reason an air-breather like Brochis should be more upset by this than a non-air-breather like Danio spp. Anyway, with the CO2 switched off, this is at least one thing that you can tick off from the list of possibilities.
The plants will be fine. Mind you, I'm not a huge fan of DIY CO2 systems at the best of times. CO2 is dangerous stuff, and without automatic dosing, it's hard to be sure you're maintaining a steady pH and a below-toxic CO2 concentration.>
I did clean one of my two filters on Saturday-other than that-nothing has changed.  Two photos are attached-any idea what this is or how to treat?
<For now, assuming poisoning. Do a BIG water change, 50%, and see what happens. If this helps, then another 50% change tomorrow would be a good idea. Also, install a very good quality chemical adsorbent to remove potential toxins; at the least, carbon, but ideally Polyfilter or similar.
If you can, get the water tested for copper and chlorine (most aquarium shops that deal with marines should be able to do this for you). Cheers, Neale.>

Re: Sick Brochis (RMF?)<<No need>>    8/22/12
Thanks for the advice.
I changed 50% of the water, d/c's the CO2 and am en-route to purchase a chemical absorbent product.
I can't really wrap my head around the idea of an external poison-I have well water, so chlorine isn't a factor, I have a breeding shrimp/fry tank that receives the same water and none of my shrimp are dying.  I don't use chemicals to clean around my tank.
<I concur with your analysis; it is very odd. Diseases tend not to be instantly incapacitating and don't tend to come out of the blue in this way. Were there no signs at all of problems before? Disinterest in food?
Not schooling with the other Brochis? Laboured breathing? More frequent gulps of air compared to the others?>
She has been swimming short distances, and it takes about 3 body lengths to turn right side up, then usually stops and rests.  I will continue the WC regimen as directed and keep you posted should there be any progress.
<There probably wouldn't be any harm taking a broad antibiotic approach, e.g., using Maracyn 1 and 2 together. At worst, it'll do nothing, but at best it'll catch any bacterial infection of the internal organs without harming the other fish or the filter.>
I greatly appreciate the speedy response and advice.  Be well.
<And thanks for the kind words, Neale.>

Corydoras Catfish Deaths (RMF, any ideas?)<<>> 12/30/11
Hi there! I hope everyone is enjoying their holiday....I sure was until I got home last night. I wrote to you a couple of months ago about my angelfish, who are doing well I'm glad to say. Unfortunately three of their little tank mates did not fare so well in the week that I was out of town. The specs are as follows:
ammonia/nitrites = 0
nitrates = 5ppm
pH = 7.0
Livestock (until last night) = 2 medium sized angelfish, 3 Cory cats, 1 Oto cat, and an apple snail
Feeding = while I was gone was being taken care of by an automatic feeder, still working. Give tropical flake and algae supplemented flake daily (sometimes brine shrimp or bloodworms as well)
Plants = moderately planted with Vallisneria, java fern, Anubias, and water wisteria (Hygro something-or-other)
<Hygrophila difformis'¦>
Hardness = I don't know but my snail is growing rapidly and growing new shell quickly so I guess water must be at least moderately hard
Tank = 29gal with 2 hang-on filters one rated for a 20 gal the other for a 60 gal and a heater set on 80 degrees.
<Whoa there! 27 C, 80 F, is way too warm for almost all traded Corydoras (the exception being Corydoras sterbai) and all Otocinclus spp. Excessive heat will stress these fish, and in turn, make them more susceptible to diseases and other failures. Most species are best kept between 22-24 C/72-75 F, and some, like Peppered and Bronze Corydoras, will appreciate even cooler conditions for part of the year, right down to 18 C/64 F.>
I've had the same set up for a couple of months now with no problem (the tank has been running for a year but previously with different inhabitants, so the system is mature). Last night I came home after being gone a week and the tank was covered in green algae and two Cory catfish were dead, the other one was swimming erratically and breathing very heavily. The other fish (and snail) seemed fine! There was nothing physically wrong with the Corys that I could see just by looking; their fins, colors, eyes, etc. all looked normal.
<Does sound like poisoning then, or else (lack of) oxygen stress.><<Agreed>>
However, I did begin a routine of API CO2 Booster and SeaChem Flourish for my plants a couple of days before I left. The CO2 booster I dosed twice (once with a water change then again two days later) and the Flourish I only dosed once (when I did the water change). I put in the recommended dose of CO2 booster, and a slightly smaller-than-recommended dose of Flourish. Nine days passed between the last water change and when I returned home.
<I see.>
I suspect that one of those two chemicals is the culprit - I know that catfish are sensitive to copper, and there are traces of copper in the Flourish, but if it was enough to affect the Corys, would it not have affected the Oto and the snail as well?
<Possibly, possibly not. Traces of copper in plant fertilisers usually aren't a problem for catfish though.>
I also know that the CO2 booster is just gluteraldehyde (sp?) which is a toxic chemical, but I put in the recommended dose so I don't know if that would've affected the Corys.
<Again, hard to be sure. But do remember plants and fish compete for oxygen at night, and tanks that look fine by day can be dangerous at night. Both the Corydoras and the Otocinclus will be oxygen-stressed at high temperatures, and at night, when there's even less oxygen in the water, things can get very bad for them. On top of this, CO2 can cause problems if not used correctly, including unstable pH levels, and I much prefer automatic CO2 systems to manual ones because of this.>
I did a 50% water change when I got home (would've done more but my silly water sucker-upper thing got clogged and stopped working) and the one that was still alive is now back to normal behavior like nothing happened.
<When oxygen levels return to normal, stressed fish usually cover without and problems. So this is perhaps a clue.>
What killed my cute little Corys? Thank you so much for your time and expertise, Michelle S.
<Happy New Year, Neale.>

Mollies and Cory Catfish... hlth. 9/19/11
I have a 10 gallon tank with 3 Cory catfish, 2 platys, and 2 female golden balloon mollies. I just got the mollies about 3 weeks ago. I've had the Corys for about 6 months and the platys for about 3 months. The mollies developed a white-ish film over the top of their heads between their eyes, it almost looks like their scales are flaking? From researching on the web, it looks closest to Columnaris, but it's hard to tell since I am inexperienced with fish diseases. I removed them from my tank and put them in a 2 gallon beta bowl. Since Columnaris is a bacterial infection(?), I've been putting 2 drops of Melafix in their water. I realize it's not an antibiotic and it's more of a preventative measure, but it seems to reduce the white-ish flaking appearance. I'm trying to figure out what else I could do for them. I know they need a filter for their separate bowl, but I'm also trying to figure out when I put them back in my 10 gallon tank with the other fish, should I put salt in the water? I know Corys are sensitive to it.. Currently, my mollies are swimming normally.. no clamped fins or erratic swimming or lethargic swimming.. If they do have Columnaris, is it contagious to my other fish?
Also, there was a 12-hour power outage about a week ago. I'm not really sure if this is related to that. I don't have an battery operated tank equipment, so they went without a filter and bubbler for 12 hours. All of my fish are very active and I haven't noticed any differences in their behavior (except the Corys swimming quickly to the surface, as if eating the air.. but that's when I added the bubbler). Although since this thing with the mollies, my albino Cory is continuously swimming vertically at the surface. He creates bubbles. I'm not sure what's going on with him.
Thank you,
<Hello Jessica. Your aquarium is too small for Mollies, and the water chemistry you have is won't be ideal for Mollies. As you hopefully realise, Mollies must have hard, alkaline water (which Corydoras will tolerate, but don't enjoy) and are actually easier to keep in slightly brackish water (which Corydoras won't tolerate at all). Melafix has little practical value here, and adding salt at a level Corydoras will tolerate (in the short term, at least) won't reduce the bacterial and fungal infections Mollies suffer from. Do read here:
Treatment for Columnaris is as per Finrot, and needs to be prompt. It isn't contagious as such, though any stressed fish can catch either infection.
Mollies are very common sufferers, typically where water is too soft or nitrate levels too high. Cheers, Neale.>

Pigmy Corys, hlth. 5/9/11
Dear Crew
I was sold six Pigmy Corys a few days ago but only four have survived. I asked if they would be ok in my tank conditions and was told it would be ok. After doing some reading, I think I might have been mis-informed as they like soft water, right?
<They do, but should adapt to "London Tap" style hard water if other conditions are okay. On the whole, Corydoras are not fussy.>
My tank is 100 litres, ammonia 0ppm, nitrite 0ppm (although had a slight spike on the day after I got them), nitrates 5ppm, PH 8, London water (hard). I used a slow acclimatisation method over an hour before I put them into the tank.
Would the hard water condition have killed them or the nitrite spike?
<The latter, with previous starvation in the retailer's tanks likely the contributing factor. Well-fed Corydoras pygmaeus are fairly undemanding.
Corydoras hastatus and Corydoras habrosus much the same.>
Thanks, Patrick
<Cheers, Neale.>
Re: Pigmy Corys 5/9/11

Thanks Neale
oh dear, bad day - lost my newly hatched Pseudomugil furcatus fry after three days (so tiny!) - perhaps he was too small for my Microworms.
Also, I think there is only one Pigmy Cory left out of six - and he has a little pink patch on his side.
<Oh dear.>
The tank now reads 0ppm nitrites (was about 0.1-0.2ppm despite water changes for a couple of days). My suspicion as to the sudden nitrite spikes now rests with the road works they are doing outside our flat - each time they return to work, we get this problem so it might be disturbing the water pipes?
<Ah, yes, I can see why this might be a worry. Not much you can do save waiting until the workmen leave. Do avoid doing water changes when they're about. Drinking water should of course be safe, so the risk shouldn't be that great. But who knows for sure? In any event, the non-zero nitrite level could indicate other issues, so do be open minded and review the aquarium. Don't add new fish for a month or two'¦ see what happens during this period.>
I just wanted to check one other possible cause of the Pigmy Cory loss - also in this tank are 6 female guppies (large!), 2 platies, 7 split fin blue eyed rainbow fish and 1 male dwarf honey Gourami. Could they be causing problems? I've not seen anything.
<No obvious problems here save differences in water chemistry, temperature requirements. London Tap isn't the ideal thing for South American and Southeast Asian fish, so review and act accordingly when shopping.>
thanks Patrick
<Cheers, Neale.>

Injured Corydoras aeneus 3/7/11
I have a question about a Corydoras aeneus (albino) please. I have seven of them, and this May will make three years they have lived with Gymnocorymbus ternetzi, Black Skirt Tetras, in a twenty gallon long tank. Everything has went wonderfully, and I have even raised some of each kind from fry.
I monitor water quality with an API kit and weekly water changes. They have a sand substrate, artificial plants and real floating plants. The Black Skirts do exhibit their pecking order behaviors, but I have only seen this result in a fin shred twice (once all the fins) and both times they healed very quickly without any medication. I have never seen them bother the Corydoras at all, even when they blunder into the Black Skirts and so on. Today one of the largest of the Corydoras has an injury that apparently happened overnight. I looked at the diagnosis chart:
and also the medication chart: http://www.wetwebmedia.com/FWSubWebIndex/fwfishmeds.htm
but I have questions. I thought most bites occur on fins, and in my limited experience, from what I have seen in other people's fish, 'spontaneous' bacterial infections (not from a wound) tend to occur more in the gill / face / pectoral 'armpit' area.
<Is the case. But this is quite clearly a combination bacterial infection and fungal infection; the red is the wound, likely infected with bacteria at this point, and the white fluff is fungus.>
I had a natural looking tank until a few weeks ago when I switched out for some other tacky but fun aquarium décor from an empty tank, and I wonder if he could have got caught in one of the holes in a decorative shipwreck and had to back out.
<Possibly; while fin-nipping might have been the trigger, Corydoras are usually nipped on their dorsal fins first, and there's no sign of that here. The adipose is what's infected here. It's a small fin, and might be damaged by sharp objects. But it's all rather mysterious.>
The shipwreck is easy enough to remove, but removing the Black Skirts would be another matter. I have read on your site that a hospital tank should be as good as the home tank, but I only have a ten gallon available which of course if half the size (I don't know if he needs to go in there or not).
<I would treat in the main tank.>
What do you think is the cause if this injury?
<Very hard to say. The adipose fin is rarely nipped and if the problem was with the substrate, you'd expect to see inflammation of the belly and erosion of the barbels.>
Are the Black Skirts more likely to nip him now with this exposed blood on him?
<Unlikely, but keep an eye on him.>
If his plate is pulled up as it appears to be, is the normal healing for it to fall off, or for it to lay back down again? I have never had to medicate these fish before, so can you tell me the seriousness of this injury? He is moving about on one side of the tank and takes food, etc. I have attached a 79.5 kb photo of the injured fish near the suspect ship, and a 312 kb close-up of the injured area.
Thank you,
<Would treat with a reliable anti-Finrot and anti-Fungus medication, for example eSHa 2000 in Europe or Seachem Paraguard in the US. Cheers, Neale.>

Re: Injured Corydoras aeneus 3/11/11
Dear Neale,
Thank you for your reply. After the pet stores opened up the next day I was surprised to find that they did not have the product you recommended (they are major pet chains after all) but when I came back to check the fish he was dead.
<Oh dear.>
I have ordered some of the medication in case it is needed again. I will look around on WWM and see if there is a list of things everyone should have in their fish medicine cabinet.
<On the whole, no. Apart from medicines having a definite shelf life, a properly maintained aquarium almost never gets sick. Salt is useful for treating the commonest problem, Whitespot, and at a pinch, non-iodised cooking salt works fine for this.>
Since there had not been any more fish added for almost three years (except their babies), and their care is consistent I did
not consider having lots of medicines around. In January I did have a large Black Skirt die (found sucked up by the filter, no signs of any disease or injuries) but since all seven were eating and looking fine the day before and everyone else seemed normal I chalked it up to old age. I took all the new décor out of the tank and put the old back in just in case it caused the injury and death of the Corydoras.
<Hope this is the last fatality for a while! Corydoras should live at around 5 years, and I have some elderly-looking specimens around 6 years old. Cheers, Neale.>

Series of Panda Corydoras deaths 2/24/11
Hello crew,
What a shame that I only contact you when things are going wrong!! I still peruse the boards and FAQs with interest, so thanks as always for the marvelous site.
<Thanks for the kind words.>
I started out wanting to query the reason for the steady demise of first 2,then a 3rd, and finally a 4th panda Corydoras catfish. Having typed out my set-up, water parameters and current stock and maintenance practices, however, I suspect I know what's happened (indeed from the FAQ's I certainly should). Even so, I would really appreciate the benefit of your wisdom to avoid a repeat performance, if that's alright. It's a bit lengthy but if nothing else, it will provide a lesson to other FAQ readers'¦
Set-up is a 90 litre Fluval Roma 90 litre (20 US gallon) freshwater tank with Fluval U2 internal filter, about 5 months old - I cloned an existing mature filter at the time of setting it up, so the new tank cycled quite quickly.
<All sounds fine.>
Water parameters generally stay at nil ammonia, nil nitrite, 5- 10 nitrate. Temp 25c/77F. Ph on the high side at 8, hardness 5 GH. I use mains tap water with usual de-chlorinator etc.
<Do understand 25 C is absolutely at the top end of what almost all Corydoras find comfortable. Is that the cause of death? No; but it's always wise to keep the vast majority of Corydoras at 22-24 C, and to choose tankmates that appreciate the same thing: Neons, Platies, Swordtails, Danios, most Barbs, etc.>
Substrate is black sand (more of a fine gravel really), some ornaments, a 6 inch bubble wand, lots of hideaways and plastic plants, and it's about one quarter planted (with thick Vallisneria spiralis).
<Black sand can be tricky with Corydoras because most of it is a byproduct of glass manufacturer rather than sand, and it has a rough, abrasive quality that plays havoc with their barbels and underbelly. Again, unlikely the cause of death, but do check your sand or gravel feels silky smooth rather than rough.>
I usually do 20% water changes and brief substrate vac weekly, and do a better clean and filter rinse (in tank water obviously) about once every 4-6 weeks. There is some moderate green algae which grows as a fine fur on most surfaces - I clean it from the glass and the lighter coloured plastic plants, but leave it elsewhere for the fish to graze on. Lighting is on for 12 hrs per day.
I have 10 Neons, 9 dwarf Puntius gelius barbs, 2 small striata and a yo-yo loach, 2 dwarf gouramis, a dwarf Bristlenose (2 inches long), 1 tiny bumble-bee goby, and 5 Amano shrimp. I feed once per day - sometimes giving them a fasting day - a variety (not all at the same time) of spirulina crisps, algae wafers, flakes, sinking pellets, frozen peas, and a frozen mix of bloodworm/brine shrimp/daphnia. They sometimes make the wafers last, but otherwise all food is gone in 5-15 minutes.
<Again, all sounds okay.>
I did have two other yo-yo loaches up until 3 weeks ago, which I re-homed as they grew enormous and were bullying everything in the tank. I also had a mini-school of 5 panda Corys - and here is the issue, as I find myself down to just one.
<Indeed, Yo-Yo loaches, and indeed loaches generally other than Kuhli Loaches, make poor companions for Corydoras.>
Regrettably the maintenance of the tank fell apart a bit a few weeks back (long story of boring personal crisis), and I confess I did nothing with it for about 5 weeks (apart from feeding the fish sparingly once per day). One of the larger panda's started sitting on the top of the filter occasionally, under the lights, but was otherwise acting fairly normally. I realised this was likely to be down to poor water quality and kicked myself into touch..I tackled the tank, and discovered that the panda fond of sitting on the filter seemed to be struggling to swim. I hoped that I hadn't left it too late, but sadly despite a good clean and water change, and removing the 2 huge bullying loaches, the panda was still suffering, upside down and unable to swim properly after 48 hrs, so with huge regret I euthanised him.
<Oh dear.>
And when I went to observe the other pandas to see how they were doing by comparison, only then did I realise there were 2 missing completely - I had assumed they were hiding away from the bullying loaches (the more they bullied, the more hiding places I introduced), and that's why I only ever saw 2 or 3 at a time. Very poor observation on my part.
<Perhaps so.>
The 2 remaining pandas were very dark in colour, which my LFS sternly informed me was down to the stress of a) the beastly loaches and b) the water quality. I got my act together and have been taking much better care of the two survivors..since shipping out the loaches and giving it a careful clean, the entire community is happier. The two panda's lightened in colour over the course of a few days, and they were back to fluttering around the tank with a pinkish hue quite happily again.
But after watching them swimming around and feeding normally a couple of nights ago, I gave the tank one final glance before going to bed, and saw one of the remaining pandas upside down in the plants, gasping for breath. By the time I'd fetched a small cup of iced water and the clove oil (I couldn't bear to think of him suffering overnight needlessly), he was dead.
<You don't need the ice water with the clove oil. Indeed, the thermal shock would defeat the object of using clove oil as a sedative! Just take 1 litre of water from the tank, put into a container, add 30 drops of clove oil, stir well, then immerse the fish, making sure it can't rise to the surface to gulp air (Corydoras can do this, and obviously the more the air they breathe, the less they use their gills, and the less they absorb the clove oil). After 10-15 minutes, you should find the fish has passed away peacefully.>
I guess my rescue operation came too late for him, despite 3 weeks of apparent normality? Why did he go so suddenly?
<No idea.>
Incidentally, of the 4 I lost I inspected 2 of them, and there was nothing obviously wrong with the bodies..no white marks, no sores, swellings, blisters or wounds, barbels quite long and intact. One was missing most of his tail fin, but I put that down to the loaches snapping at him when he was unable to swim away.
<Stress could easily be an issue, and water quality, hard to say which it is. But either way, you might not see any physical symptoms.>
I realise the last survivor needs more of his own species, but I don't want to rush out and buy another 4 in case it was not simple poor water quality that expedited their demise, but something else more mysterious (i.e. not the fault of a crappy fishkeeper).
Just before Neale tears several strips off me (if he hasn't already, further up in this rambling text), is it safe to say I caused this through lack of maintenance for a period of weeks?
<Impossible to be sure. But all else being equal, if the tank is now settled down and everyone seems happy, you could be justified in putting your fatalities down to this.>
Should I wait to see how the lone ranger fares before getting him some replacement tankmates, or just hurry up and get some?
<Yes, I'd wait; give it at least 3-4 weeks to make sure the tank is stable.>
If anyone else is reading this whilst assuming that a few missed water changes won't hurt, just spare a minute to think of the species you have and whether or not they are hardy enough to handle a spell of poor water quality. I suspect these cute little catfish were not. :o(
<Corydoras panda are indeed towards the delicate end of the Corydoras spectrum, at least when compared to Peppered or Bronze catfish. But they're still quite hardy fish.>
Thank you for any insights, and perhaps forgiveness for my confession.
<Cheers, Neale.>
Re: Series of Panda Corydoras deaths 2/24/11
Hi Neale,
Thanks for the quick response....part of the reason for the long email, as well as trying to pin down a reason for the loss of my pandas, was to get an all-round expert opinion on my current tank set up....and you have done that, so thank you!
Re the temp.....dammit, stupid me....I recall reading something about the Corydoras preferring a specific end of the spectrum, but I incorrectly remembered it as being the WARMER end. I'll notch the heater down a little (slowly) over the next few days to see if I can make the last remaining panda more comfortable. A little knowledge is a bad thing sometimes.
<Corydoras sterbai is about the only Corydoras species happy at 24-28 C, hence it's reputation as the "Discus tank Corydoras". All the others prefer cooler water because they come from shallow, well-oxygenated streams. In fact I've kept Corydoras paleatus outdoors during English summers, where they did just fine.>
Re the black sand......I originally had quite a soft, grayish mixture of smooth sand, but when I topped up the new tank I bought a different brand which is indeed rather more glossy and glass-like. Hence it looks like very fine gravel to me, although it does feel smooth to the touch. Curses.....is it worth simply mixing in more soft sand, or should I remove as much of the glossy back stuff as I can without disturbing the plants, and replace it? It's not terribly deep, maximum of 3cm where planted and shallower elsewhere.
<If the Corydoras have long barbels with narrow, needle-like tips, then the sand is fine. If the sand is sharp, you'll find the barbels barely stick out a few mm from their mouths, and the tips will be rounded. Smooth silver sand from the garden centre is ideal, but fine gravel should work well too, just so long as it has rounded, not jagged, edges.>
I'm always faintly concerned that the gravel vac, which I use as I'm syphoning off water to change, is quite weak and only sucks up a minimal amount of gunk from the sand surface (the Bristlenose, small as he is, is an incredibly messy beast). The rest gets stirred up and eventually taken up by the filter or broken down by bacteria, I guess? I bought an air-pump driven vac with a little bag, but the suction on that is really poor, despite a pretty robust pump. The sand is disturbed/stirred when I move the ornaments for cleaning, plus I have a few assassin snails and possibly a few tiny tiny Malaysian trumpets under there - does that sound like enough to keep it reasonably clean and free of noxious gas pockets? I've considered pipetting up visible waste and squirting it into a net manually, but that may be getting a bit carried away.....??
<Yes, the sand will be fine. In fact sand tends to cause problems when disturbed rather than left alone. If you have some burrowing snails and/or plants, it'll be fine, and effectively self-cleaning. The denser sand at the bottom helps to remove nitrate. Do read:
Re the suitability of the loaches, granted the LFS (M'head Aquatics, fantastically helpful people) did warn me to keep an eye out for the loaches bullying the Corys. They indicated, however, that where there was plenty of food, reasonable space, and refuge for the cats, it shouldn't be an issue.
<Indeed, but does depend on the Corydoras. Corydoras paleatus for example should be bolshy enough to get by, but little C. panda'¦ not so much.>
But these particular 2 loaches grew unusually large - I bought 3 but the 3rd remained quite small. Those I have left now were quite passive.... until I moved out the big chiefs. Now I have a new problem, with the 2 small striatas and the remaining yo-yo now fighting one another quite frequently, and occasionally having a go at other small fish.
<Yes, what they do. All the Botiine loaches have the potential to be troublesome.>
If the LFS will have them, I'm prepared to give up on them altogether...I got them for a bit of variety and to liven up the tank, with the assurance of the LFS that things would work out ok, but whilst fun to watch they appear to be total hooligans. I've got two Neons with one eye apiece to remember them by, even if I can't hold them directly responsible for the death of my Corydoras.
<Maidenhead Aquatics will usually take back fish, so shouldn't be an issue.>
Thanks for the tip on the kindest euthanasia method, I obviously hadn't properly understood how the clove oil worked. I hope I won't have to use it again anytime soon.
If the tank settles and I can move the last of the loaches out, I'd like another little shoal of the Cory cats....perhaps a different species, if the last panda makes it and will shoal with them?? There's some Adolfoi's at the local LFS.....or perhaps stick with bronze or peppered, given my chequered history? :o)
<Oh, do try C. panda again, perhaps four of them, and four C. adolfoi if you want. In any event, C. panda isn't delicate by fish standards, so well worth trying again.>
Thanks again for the oversight, I do appreciate it. Now to chat up Maidenhead to take the last of the loaches'¦...
<Cheers, Neale.>
Re: Series of Panda Corydoras deaths 2/26/11

Thanks Neale, you're a legend as always.
<Be sure to tell my girlfriend. She needs reminding.>
A couple of days on and the lone panda Cory seems to be doing okay. He's swimming actively (occasionally with the pygmy barbs!),
<Yes, the do this; their instinct to school is very strong.>
seems content enough out in the open, and appears to be feeding. Pic attached.....sorry, I couldn't get a decent image of the barbels, but following your description I had a good look.....I can only see two pairs, the uppermost, longer and slender pair, and the inner, thicker pair. The upper ones are about 3.5mm, the inners 3mm.....but hard as I try, I couldn't honestly say they are needle-like. Having looked at some online images of how the barbels should be, it looks as though the very tips of the needles of his have been worn off, so I guess that "sand" is indeed too harsh.....I'd better switch it out for something softer.
<As/when, yes, that'd be a good idea. Smooth silver sand can be bought in garden centres and is very cheap, around £3 for 25 kilos from my local garden centre. It does have a bright yellowy-brown colour though that not everyone likes (the fish don't care) and while it does darken with time (algae and bacteria coating the grains, presumably) some aquarists prefer to use very fine pea gravel or coloured aquarium sand (e.g., black sand). But as we've discussed before, some sand is too sharp, e.g., Tahitian Moon Sand, so spend some time researching this. Look for aquarium sands states as being "soft belly safe" or words to that effect. The CaribSea web site for example states whether this is true or not for all their substrates, making selection easier.>
It's been a week since the last water change so I did some pre-water change tests, just to see if anything is going on, or if I need to up the changes for a while....but everything is totally "normal" (0 ammonia, 0 nitrite, 10 nitrate), so happy days.
The loaches are a bit obnoxious towards the panda, but he skitters away and comes right back out again so hopefully he's not overly bothered.
<Hopefully not. On the whole the bigger Corydoras, like Corydoras paleatus, handle themselves rather better with loaches than the smaller species. The big Brochis species would be even better.>
I notice the Bristlenose, which is getting rather large, can be a bit spiteful towards him as well.
<Territorial, more than spiteful, I'm sure.>
Will a large enough number of Corydoras cope with that as a group?
<Should do. Certainly, your Bristlenose poses no threat, and will only shoo Corydoras away from its nest and/or bits of food it wants for itself. Loaches are more of a gamble, as I've said before.>
<Cheers, Neale.>

Re: Series of Panda Corydoras deaths 3/1/11
Thanks again for all the help and advice.
Yesterday I cleared out about a third of the sharp black sand, leaving the plants undisturbed, and covered what remained with 1.5 inches of much softer grade grayish sand, which I'd had in a previous tank - I'd washed it until the water ran clear prior to its previous use and got no residue, and washed it again this time, but still it gave the aquarium water a grayish hue?
<Silt, perhaps some diatoms and bacteria; will clear in time.>
Wonder why its releasing a residue the 2nd time around, hope it won't cause the fish a problem while the filter battles to clear it? They all seem to be alright this morning.......
Anyway, the little panda Cory had an instant return to form and was busy rummaging through the new sand as fast as I could add it.
<Nice to know.>
I made a trip to Maidenhead Aquatics to get some additional assassin snails, given the extra thickness of the sand, and now have my eye on some of their current Corydoras stock. They have some Julii, a peppered variety (Emerald??), plus Masked and Adolfoi. The last two are really expensive. Can't find any pandas, hope my last one will school with another species ok.
<Often do. Helps if similar in size, colouration.>
After studying the barbels of the fish in the store, my surviving panda most definitely has very worn barbels. How upsetting.....I guess this could have been the cause of their demise, if the water quality was not as poor as I thought. Hopefully the new sand will allow him to recover....do the barbels re-grow?
He was happily scoffing a live bloodworm last night, so I take it he's feeling alright despite being alone.
Intrigued about territories, have been trying to work out the dwarf gouramis captive areas...'¦..
<Dwarf Gouramis favour patches about 20-30 cm square at the surface among floating plants.>
Thanks again
<Glad to help.>
<Cheers, Neale.>
Re: Series of Panda Corydoras deaths 3/1/11
Now you've gone and done it. I don't have any floating plants, only a cluster of planted Vallisneria spiralis (a patch about 8" x 8").
<These can work, once their leaves reach the surface. I do find Vallisneria become hair algae traps sometimes, but your Gourami couldn't care less.>
Now you've got me feverishly researching floating plants for the gouramis.....Riccia fluitans or Sylvania
natans are the favourites so far,
<Both are good plants, though Riccia can be difficult to establish in tanks with strong currents. Salvinia natans is widely traded. Be sure to use the right Latin name! Places like Wildwoods routinely have it in stock.>
not that they appear very readily available apart from on eBay.......and that has only given me ideas for a beautiful green rug on the open area of substrate...'¦.
<My favourite is Indian Fern, a species Bob F. enjoys too. Few plants are as pretty and as useful. It's an unruly species, yes, but only because it's so vigorous!
Damn silly hobby, I'll probably kill the plants. The Vallisneria simply got lucky. :o)
<Better to say Vallisneria is more adaptable than most of the other plants traded, so it does well even if conditions don't suit other species. There are a few other bullet-proof plants out there: Java fern, Anubias, Cryptocoryne wendtii'¦ it's really a question of researching your plants and matching them to the conditions (light, temp., water chemistry) being offered.>
<Cheers, Neale.>

Re: Series of Panda Corydoras deaths 3/3/11
Hey Neale,
I fully intended to liberate you from your torment and sign off with a big THANKS, for all the help and the link to the plants article, and you're dead right, the Vallisneria is indeed coated with hair algae.
<Combination of bright light and poor water flow at the surface causes this. Pull away "infected" leaves AT THE BASE, and be sure not to bury the stem of the Vallisneria in the substrate. Once the leaves are damaged at the base, the algae hits, BIG TIME. None of the green or white part of Vallis should be in the substrate, just the roots, the tops of which should be just visible above the substrate.>
My final choices for floating plants are perhaps the Salvinia (SALVINIA!) natans and maybe water lettuce.....will consider the Indian fern later.
However, sadly I have to report that the surviving panda Cory cat is not doing so well......he seems to have taken a turn tonight. :o( He is quite motionless - he's not distressed, or breathing rapidly, he's just sitting still mostly, listing slightly to one side, occasionally fluttering away from another fish passing him. I fed some peas this evening and he drifted out for a short time to rummage half heartedly through a few morsels, then he drifted back to his spot under a plant.
<Oh dear.>
By way of a summary, he has been active and feeding for a few days since his last companion died, and seemed to rally after a change to the softer substrate two days ago. Water parameters have been stable. If I lose him, he'll be the 5th Corydoras to die over a period of about 5 weeks, yet none of my other five species have shown any problems at all. Combined with the marked wear of the barbels on this fish, I guess its safe to assume that the others also had worn barbels (I just didn't realise, as I had nothing to compare them with).....there was no damage to their bellies, only the barbels. Does this mean they were unable to feed properly?
<No, they can still feed. But the lack of barbels does imply less than perfect conditions for Corydoras.>
Is it more likely that there was an underlying bacterial infection which affected them all due to the damaged barbels....perhaps due to the brief lack of water changes and possibly grubby substrate?
<Possibly, but do remember, these catfish naturally plough through mud and silt. So "grubby" isn't a problem if the water is clean and the water current brisk.>
I wish there was something I could do for the panda.....could I treat for an infection? Is it too late for him?
<Hard to say. Would wait and see what happens. Doing a water change is rarely a bad idea, and it's well worth upping the oxygen content of the water if you can. But beyond that, without any clear idea of what the problem might be, medicating can be counterproductive.>
<Cheers, Neale.>
Re: Series of Panda Corydoras deaths 3/3/11

Very interesting re the Vallisneria....the white parts are indeed submerged, so I'll fix that.
<Quickest way to kill your Vallisneria! If all else fails, just bury the tips of the roots in the substrate, and leave everything else above the substrate.>
The fish seem happy to snack on the algae, it's not there to huge excess, but the plants themselves could do with some thinning out. Can leaves be cut back near the base?
<Yes, but trimming Vallisneria needs to be done carefully. It's a bit like peeling a globe artichoke. Take the leaf off right at the base, taking great care not to damage the other leaves. Don't allow gravel or sand to get between the base of healthy leaves and the "stem" part of the plant, otherwise the leaf gets damaged and eventually dies. Plants can't heal leave -- they shed them -- and Vallisneria is notoriously finicky when manhandled. It's a plant that does much, MUCH better left to its own devices with as little fuss as possible. Given the right amount of light, and if planted properly, it's perhaps the easiest rooted plant of them all to grow, with only epiphytes like Anubias and Java fern being noticeably easier.>
The panda Cory is holding on, so far. Observing him last night and this morning, I'm wondering if he's simply starting to suffer from the lack of same species company....but he is feeding, so unless feeding is simply instinctive in fish, hopefully this means he is not close to death at the moment. There are none of his species at the LFS, I will have to look further afield, although this could mean they'll have to travel in a bag for over an hour, which isn't ideal.
<Oh, heavens, Corydoras will travel an hour without any fuss! So long as they don't become too chilled, you're fine. Remember, they're air-breathers and tolerate low-end tropical conditions, and these two traits are why they quickly became aquarium staples compared to other types of fish. Your only problem is making sure their fins don't burst the bags, so be sure not to pack too many per bag, and double bag them.>
It's true that the water movement is poor in this tank, compared to my last tank which had a more basic filter but a strong powerhead. The Fluval 2 does very little to move the water around - there are some different settings, but none of them seem to produce any decent current to speak of. The air flow setting stopped working after the first water change.
<Time to add another filter, methinks. A decent external canister filter -- ideally an Eheim if your budget runs to that, in terms of long-term value for money -- will make all the difference in the world. The Fluval externals are pretty good, too. Canisters allow you to have the inlet at the bottom of one end of the tank, and the outlet at the top at the other end of the tank, the ideal arrangement for good water flow. Alternatively, placing another internal filter at the other end of the tank, perhaps deeper down the water, would help, but internal canister filters are less good value for money in some ways, and pretty unsightly.>
I do have a 6" air stone in the centre of the tank, which provides a small amount of surface movement. I'm now researching a powerhead of some description to increase the current - but I'm confused as to what flow rate would be appropriate for my small tank (90 litres, 45cm deep x 60cm wide), particularly bearing in mind the Gouramis.
<A good rule of thumb for a mixed species tank would be 6 times the volume of the tank per hour, so in your case 6 x 90 = 540 litres/hour, which would be about as much as provided by an Eheim 2215 on its own, or an Eheim 2213 alongside your little Fluval. You could tweak the current down or up a bit using the taps on the canister to get just the right amount. Spray bars are super-helpful at spreading out current, so gentle swimmers like Gouramis aren't pushed about.>
With the fish I have (Corydoras, loaches, pygmy barbs, neon tetras, dwarf gouramis), should my aim be to increase the current at lower and mid levels?
Would a simple, one directional 1000 LPH powerhead be sufficient for the catfish etc, if I position it at the bottom, but not too much for the Gouramis at the upper levels?
<A powerhead will push water along the top, while sucking water in at the bottom. If combined with an undergravel filter this can work rather well, but by itself, I'd honestly recommend at least another internal canister filter, simply so you get some filtration alongside the water current.>
Might this additional movement be adequate to reduce the hair algae around the tank a little, and lift up more of the waste I'm battling with on the substrate?
<Oh yes! Algae thrives when plants don't, and Vallisneria evolved to live in flowing water -- that's why their leaves are so long and bendy. I'm sure that flowing water helps to keep them clean to some degree.>
Would I still be able to maintain an area of floating plants with the extra current?
<Yes, but the floating plants end up at one end. Quite nice in some ways, as it divides your tank into two habitats, one shady and the other bright and open.>
Thank you
<Cheers, Neale.>

Re: Series of Panda Corydoras deaths/possible Flexibacter?? 3/10/11
Gruetzi Doc,
<Wie geht's?>
Okay, need to consider treatment of possible Flexibacter then'¦.
<Flexibacter columnaris, so-called Mouth Fungus.>
Miss Ancistrus has been out and about this evening and those tiny cottony tufts are visible again - two flecks, one on each side, perfectly symmetrical. So small that I have to really strain my eyes to focus on them, and make sure it's not just some weird trick of the light. Nope, definitely there, definitely white and thready.
<Could be plain vanilla Fungus, rather than Mouth Fungus; Mouth Fungus tends to be more grey and slimly looking than the cottony threads of plain vanilla Fungus.>
So what's the best commercially available treatment?
<Methylene Blue is the standard anti-Fungus.>
I think I read about most "Fungus"/Finrot treatments containing the right antibiotic somewhere, I'll go look again.
<In the UK, a medication called eSHa 2000 treats Fungus, Finrot, and Flexibacter columnaris (Mouth Fungus) all at the same time. I've used it safely with catfish and puffers, so I don't think it's especially toxic.>
The presence of bacteria must be down to poor water quality at some stage.....perhaps going back to the 6 weeks neglect in January, when I first started losing the Corys?
Could it have caused the loss of the panda Corys, even with no outward signs?
<Can do.>
A long shot, but can it be introduced by feeding live food...is that a myth, that those little tubes of are infected with all kinds of bacteria?
<Depends on the live food. Brine shrimp is completely safe, Daphnia usually very safe. Bloodworms much less safe, and Tubifex by far the most unsafe.>
Okay, thanks for the recommendation re my little community, I'm honoured!! Happy to ship out the loaches and the Gouramis (much as I like the two dwarf variety, the honeys less so).....had a peek at Laetacara curviceps, yep, a Dwarf Cichlid (maybe a pair?) would be tres cool.
<They are nice, shy dwarf cichlids. Colours change remarkably, and look best (greens, blues) in dark, peaceful tanks with plenty of overhead shade and no aggressive tankmates. Tend to be paler (grey, yellowy) in bright tanks with few plants, no shade, and aggressive tankmates.>
I have, however, often gazed adoringly at Mikrogeophagus ramirezi when they have them at the LFS, the beautiful German Blue Rams.....I have a sneaky feeling I've toyed with the idea of these before, but was dissuaded for some reason.
<Near-useless species for casual aquarists. Needs very warm, very soft, very acidic conditions; 28-30 C, 1-5 degrees dH, pH 5-6.5. Lifespan in most aquaria is less than six months. Very, very prone to diseases including Mycobacteria and Hexamita. An ample literature on this species.>
Not certain my water parameters were thought suitable. How about one of the other more brightly coloured species of Dwarf Cichlid?
<If you can find them, Mikrogeophagus altispinosus is quite hardy and does well in moderately hard water. Apistogramma cacatuoides is another reliable species. In hard, basic water, Julidochromis ornatus is a dwarf Tanganyikan that works well in community tanks because it is only aggressive towards other cichlids; singletons or pairs will ignore midwater schooling fish completely, though they may harass Corydoras if there isn't enough space for both catfish and cichlids.>
I definitely rate MA.....there are two stores I frequent, Farnham and Havant (wasn't that taken by Hickstead down near Gatwick, but that was more to do with their general attitude than their expertise). The manager at the Farnham branch always bowls me over with his knowledge, I believe he keeps a Dwarf Cichlid which he shows (there is such a thing as Cichlid Shows??)?
<Yes indeed.>
He told me once that he thoroughly defrosts and/or washes its food before feeding and adds vitamins to it. That's proper dedication'¦.
<Quite so.>
Thanks as always - will go and do a fresh search on Flexibacter on WWM to find suitable treatments, as I will no doubt be rushing to get some before you have an opportunity to respond!
<Cheers, Neale.>
Re: Series of Panda Corydoras deaths/possible Flexibacter?? 3/12/11

Hallo, bin Ich sehr guter dank Neale, wie über Sie?
<Also Ich bin sehr gut, danke. Und dein fische'¦?>
It's been an expensive day. The eSHa 2000 has been duly purchased to tackle possible fungus, along with a very small hospital tank with its own sponge filter (which I am running in the main tank as we speak/type)....but I now can't decide whether to isolate the Bristlenose and treat only her, OR remove the shrimp and snails (I know it says shrimp safe, but it does contain 8mg copper sulphate) and treat the main tank.
<I would remove both shrimps and snails to the hospital tank for now, and treat the fish in the main tank. Medications tend to kill snails and shrimps. If you don't feed the shrimps and snails, even a small tank without a filter should be adequate, provided you change some of the water daily. Adding a little sponge filter will improve things further.>
She's the only one with any signs of infection.....what would be best?
<See above.>
If I do treat the main tank, the internal filter contains poly/carbon pads.....however, it has been in use for 5 months, so am I right in thinking that the carbon element can now be considered inactive, so I can simply treat with that filter in situ?
<Carbon will remove medications, but once carbon has been in use for more than a few weeks, yes, it is largely inactive and acts merely as a substrate for the filter bacteria. Still, it's one more variable. I'd remove.>
MA did actually have a few Apistogramma cacatuoides in stock, but I'm rather more taken by Mikrogeophagus altispinosus (the Bolivian Ram Club has me sold on these fish) and I'm happy to wait a while for the tank to settle. Will I have room for a pair d'you think?
<Mikrogeophagus altispinosus is a superb species. It is a trifle larger than the Common Ram, maybe 6 cm long when fully grown, and its colours are a tad less brilliant, tending towards grey-white with red, black and blue markings. But it is still a colourful fish and by dwarf cichlid standards extremely robust and easy to keep. It is probably the best dwarf cichlid in the trade. If you get good specimens, and you keep nitrate levels below 20 mg/l, you shouldn't have any problems with it. A pair will be fine in a tank as small as 75 litres. They don't damage plants, but like Mikrogeophagus ramirezi, the "Mikrogeophagus" part of the name means "little earth-eater" and they do like to sift sand and extract tiny particles of food.>
By far my most exciting and extravagant purchase today, however, was......*drum roll please*......a Fluval 205 external filter.
<A good filter.>
I researched the Eheims you mentioned, and a number of other reliable makes at good prices, but quickly discovered that Fluval, with exceptional long-term marketing planning, have designed the Fluval Roma 90 cabinet to accommodate very few other makes of external filter other than, well, Fluval. Neat thinking, huh?
<Or something'¦>
I'd have gone for the more powerful 305, as it would have just about fit, but MA convinced me this would be overkill for 90 litres.
<Could well be.>
They were also kind enough to give me a good deal (some of their branches will price match if you ask politely and take some evidence of an online offer).
<Indeed. Right now, it's a buyer's market in retail generally.>
I'm dying to set it up right now, however, it definitely has bags of active carbon amongst the supplied media, so I'd better decide whether I'm treating the whole tank or just the Ancistrus before I start up the new external.
<Would set aside the carbon for now. I like to use just plain vanilla sponges or masses of ceramic hoops in Fluval filters. If I recall correctly, these filters have a couple of sponges on one side of the filter canister, and a couple of boxes on the other side for filling with media. On my Fluval 104, I've got ceramic hoops in those two boxes. You can also fill them with filter floss if you want something cheap and cheerful. The sponges will handle biological filtration, and the filter floss will take care of silt, and if you replace the floss every month or two, you should have crystal clear water.>
Having said all that.....the Ancistrus has come out to feed her face with cucumber tonight, and surprise surprise, not a cottony spot to be seen on her anywhere. I was alarmed to see a bright white, even silvery spot on the face of one of the Dwarf Gouramis though.....no bump or tuft, just a silvery spot. More like the other male has pecked his face, perhaps? They do squabble a bit.
<Yes, they do squabble.>
So now I'm in a quandary over whether to bother to treat at all. I can't even supply pictures, the Ancistrus in particular skitters away so fast.
<If the fish appear to be healing, then leave them to it.>
Will gladly take your guidance on my next move....to treat or not to treat, in the absence of reliable evidence of infection?
Oh.....but good news on the sickly Panda Cory. He is visibly better. Swimming with the others, a little lighter in colour now, regaining some of his former flutter and flexing his stumpy barbels with more enthusiasm. Thanks for all the advice, let's hope he continues to improve.
<Am hoping.>
Just as a parting question, changing the subject back to plants, I'd like to spread the Vallisneria around the tank a bit more ready for the Rams - it's all clumped in one front corner and getting crowded. Can I gently lift it all out of the substrate, separate the plants, and re-distribute/re-plant in a different position (without burying the white parts this time)? Is that too much disruption?
<Vallisneria handle this just fine. The only thing is to make sure you don't get sand or gravel in between the leaves and their attachments to the stem-like structure (called a "crown"). Snap off baby plants by the runners, but leave a bit of runner attached rather than risk breaking away part of the crown by trimming too close. Then, so long as you only put the roots in the sand or gravel, you should be fine, and Vallisneria handles transplantation very well.>
Dank, hat ein gutes wochenende. I'm not German, merely getting in some practice for a forthcoming trip to Zurich'¦'¦
<I see! Yes, I hope to have a good weekend indeed. Off shortly into London for lunch in Chinatown. Cheers, Neale.>

Re: Series of Panda Corydoras deaths/possible fungus/now a mini-cycle, chatting 3/14/11
Mornin', hope London and Chinatown was good?
<Yes indeedy!>
Quick update.....I set up the new external on Saturday, seeding it with a third of the media and a healthy blob of gunk from the existing internal. Yesterday I carefully uprooted the clump of Vallisneria Spiralis, trimmed off the many plantlets and re-distributed around the tank with a little fertiliser in the substrate.
<Cool. I have never found Vallisneria very demanding in terms of fertilisers, though the odd fertiliser tablet in its roots won't do any harm. But it really is a classic, low maintenance plant that wants for very little.>
Tank now nicely laid out, less cluttered and much cleaner, ready for a couple of Bolivian Rams in the next few weeks after the Gouramis and loaches have moved out.
<Sounds good.>
And in doing all of this, I think I've kicked off a mini-cycle. *slaps forehead*
<Perhaps, but plants can dramatically speed the cycling process off, so don't be too disheartened. Apart from absorbing ammonia directly, they also carry lots of "good bacteria" that perform the biological cycle. It's perfectly possible to create a tank that relies 100% on plants for water quality -- in fact many ponds work exactly that way!>
The ailing Panda Cory is very weak again, barely able to hold his position in the water, and one of the Striata loaches doesn't look too clever (pale and less active than usual).
<Don't feed for a couple days, at least.>
Even the Assassin snails have popped up out of the sand, and I don't see them that often.
<Quite possibly pushed out of shape by digging up the substrate. If they come up to the top of the tank to breathe, that's a much worse sign.>
I tested the water this morning, and although Ammonia is 0, Nitrite is indeed reading 0.05 and Nitrates are a fraction lower than normal between 5-10.
<I see.>
If my understanding of the cycle is correct, this indicates that it's almost over already? The rest of the community seems fine. I'm thinking a water change to get the nitrite down, then let nature take its course?
<Yes, would do nothing much more than wait and see. Don't feed. Do an extra 25% water change every second day for this week. Should be fine.>
<Tschuess! Neale.>
Re: Series of Panda Corydoras deaths/possible fungus/now a gabby-mini-cycle 3/16/11

Hey Neale,
Thanks for latest pointers. Tank is settling after a further 25% water change, ammonia and nitrite both currently 0 - whole tank is noticeably livelier and even the weak panda Corydoras has improved.
Thought it would amuse you to know that, to save bothering you with any further insignificant questions veering off the original topic, I would venture back to a popular fish forum. Not WWM unfortunately, I can't seem to add a new post there even though I'm member? Must be going blind.
<Odd. WWM does have a forum, and you should be able to post there without problems. Do send a message to the forum moderators if needs be. If still doesn't work, let me or Bob F. know.>
After innocently enquiring as to why my neon tetras and pygmy barbs might be swimming in impressive nose-down symmetry after the upheaval of the weekend, I "learned" the following; that the current is now too strong for the mid-water shoals, that the tank is way over stocked (shouldn't have two shoals in a tank so small), and that the pH of my tapwater is too high for most species of tropical fish at 8. And of course that I shouldn't bother getting any Mikrogeophagus altispinosus as they won't handle a) the pH and b) the level of water movement.
<pH is actually less of an issue than many assume, but if you do have a pH of 8, it's likely your water is hard and alkaline, and that *is* bad for soft water fish. There are some good options for hard water, including some tetras, but you'd do well to avoid Neons; I've never found Neons do well in "London Tap" compared to X-ray Tetras for example, which tolerate hard water much, much better.>
The new current scarcely ripples the plants, for goodness sake, even the Gourami's aren't bothered. And my understanding from WWM is that as long as the pH is constant, the fish aren't overly fussed.
<To a degree, but do see above.>
The tank is indeed heavily stocked but I upgraded to an external filter and anyway, I'm shipping out 8 fish to replace with 2. I can't even be bothered to post a response, but I do suddenly recall why I stopped bothering with fish forums and deleted them all from my favourites......'¦.
<Oh dear.>
Bet all the regurgitated opinion out there drives you barmy.
<Good luck! Neale.>
Re: Series of Panda Corydoras deaths/possible fungus/now a mini-cycle 3/16/11
Okay, fair enough...it does seem that the tap water in our area is slightly hard (never got to grips with that measurement with my test kit, will get it done by MA again) and has a pH of 7-8.
<I see.>
I certainly had problems keeping guppies, but that was back in my Fluval Edge days. I've had the neon tetras for almost a year, and only lost one, and that was attacked by one of the large loaches I no longer have - maybe they can acclimatise to the harder conditions, I guess time will tell.
The only losses I've had were the Corydoras, and MA suggested that a pH of 8 could be a tad high - will never know whether it was this, poor water quality or presence of fungus that caused their demise (or all 3). Again, if the latest batch don't survive, perhaps it's the water parameters not suiting them so I won't try again.
<Corydoras generally aren't too fussy, but the tough species are best here: Corydoras paleatus, Corydoras aeneus in particular.>
Other than the Corydoras, I've not had problems with any fish since the guppies. I thought I wasn't doing too badly, I read of some people losing tank fulls of fish in one swoop!
<Quite so.>
I can try to buffer the water but going that route seems fraught with even more problems.
<Yikes! Do avoid messing about with water chemistry. Changing the pH directly is extremely hazardous. Do read about reducing water hardness, e.g., mixing hard tap water with rain or RO water.
Will soldier on and see how it goes. Thanks again for all the help, I'll try WWM forums again. <<TG>>
<Real good. Cheers, Neale.>

Extremely lethargic Cory, high nitrates 2/21/11
<Hello Angela>
I wrote about a week ago on another issue, and never received a reply.
<?! We respond to all>
I'm hoping I didn't do anything wrong and my message was just overlooked!
<More likely some "computer glitch"... As the WWM "doorkeeper" ala LeGuin's Earthsea double trilogy, I see, post all>
As it is, that issue seems to have resolved itself for the most part. Now I'm dealing with something in my other tank, and I'm hoping for some insight from more experienced hobbyists than myself.
Tank: 14gal (functionally about 11-12gal with substrate and lowered water level), Aqueon filter that came with the "starter kit", temp steady at 75*F, fully cycled and has been set up since early December 2010. The pH runs pretty steady at around 8.
<For what species of Corydoras? This is too high... I'd mix in some water of lower pH... likely RO>
I always treat new water with Prime.
<Likely not necessary, but...>
Residents: 3 peppered Cory cats, 4 albino Cory cats, 2 juvenile mystery snails. The Corys are being quarantined here, their eventual home is a 55gal. I've had them for about 2 weeks.
Tank stats last night, with API test kit:
Ammonia: 0
NitrItes: 0
NitrAtes: over 80 (YIKES!!!)
<Needs to be addressed... Have you read here: http://wetwebmedia.com/FWSubWebIndex/fwnitrates.htm
and the linked files above?>
I performed my usual 30% water change, all I had time for, with plans to do another this morning.
This morning, I tested again:
Ammonia: 0
NitrItes: 0
Nitrates: over 40, close to 80 on test kit
Performed nearly 70% water change. Retested.
NitrAtes: less than 40, but close
<You need to do something in addition to simple dilution for NO3 here>
Now for the main problem: One of the albino Cory cats has been acting lethargic for the last couple of days, is not eating well, and after last night's water change floated belly-up for a few minutes despite all my attempts to match temperature, etc. with the new water. I was afraid we would lose him, but this morning he's better. Not great, since he's still spending most of his time resting on the bottom or swimming *very* slowly a few inches, but he's not floating. Everyone else in the tank, including a new baby balloon molly that hitchhiked home with the Corys, is acting and looking fine. Even the snails, which I thought would be the first indicators of poor water quality.
<Much more likely due to the vagaries of the water changes>
The only thing that changed recently is my husband taking over morning feedings for both tanks for the last week. I think he's been overfeeding this one, because I don't know what else would have caused such a large nitrAte spike in such a short time. There was a lot of "gunk" when I cleaned the tank, which isn't normal. I've taken over feeding again.
<Ah good>
Most of the reading I've done (Google is my friend, yes?) suggests that nitrAtes aren't *that* toxic over the short term, but these levels are pretty high and I've seen people mention again and again that Cory cats are "sensitive" fish. Could the nitrAtes spike alone be the cause of this little guy's problem?
<Mmm, yes>
If so, will continued water changes and much reduced feeding be enough to resolve it? If not, what else would cause an otherwise healthy-seeming fish to be lethargic and go off its food with no other sign of disease? I'm a loss on this one!
<Please read the above citations>
Thank you so much, I appreciate your willingness to help out newbies like myself with your amazing wealth of experience!
--Angela S.--
P.S. Is it just me, or are Cory cats just the funniest/cutest little fish ever?
<Are indeed comical, and faves. I keep them as well>
I was rolling with laughter after their first "feeding frenzy" over a shrimp pellet!! I'd buy a whole swarm of these guys if I could, but hubby says no room for more aquariums...
<Mmm, maybe... Bob Fenner>
Re: Extremely lethargic Cory, high nitrates 2/21/11

Thank you so much for the reply!
<Welcome Angela>
These are albino and peppered Corys (Corydoras aeneus and Corydoras paleatus). The lethargic one is an albino.
<The C. paleatus need much lower pH... the Albinos may be either C. aeneus or paleatus>
I'm in the middle of Kansas, so our water tends to run hard with a higher pH. Even the "expert" at the local store where I purchased these guys admitted it's hard to keep soft/acidic setups here without a LOT of work, <Not so much... easy to mix some tap w/ some RO... Read here:
and the linked files above>
so I stuck with platies for our main fish. I was told that with careful acclimation the Corys would be ok, and honestly the other 6 look perfectly fine. I'll look into the RO water option, but if I can't get the pH down enough, should I find a new home for these fish?
I'm not sure what I'd replace them with. (My 7yo son wanted a school of glass catfish, but there's no way we'd be able to keep them healthy. The Corys were a compromise, since most other catfish types he liked get too big.)
<There are many tools that can/will help you identify fishes, other aquatic life that enjoys your quality water>
I use the Prime instead of whatever brand dechlorinator came with my starter kit because we have copper piping in my house. I wanted to be extra careful to avoid getting copper in my aquariums and killing snails/fish.
<Real good>
The albino Cory is still alive, but he's pretty much the same as yesterday -- not swimming much, resting on a rock most of the time. I haven't seen him eat. I did one more water change last night, being careful to get the rest of the "gunk" out of the gravel. The nitrates are now reading between 10-20ppm, which is where the tank was before its regular water change the previous week. I'm going to be feeding lightly and testing the nitrates daily for the week, I think. I'll also be buying some more plants soon, so that will probably help a bit.
<Will help>
I read as much as I could about Corys/nitrates/etc. on WWM and the 'net in general before I posted, but I probably missed something. I'll go back and check out the links again. Thank you again for the response!
<Certainly welcome. BobF

Cory catfish with skin peel (RMF, Costia?)<<Maybe, or just water quality>> 1/23/11
I have looked over the site for two days now and commend you on how well you cover everything.
I saw one post addressing this issue while I was searching, but most of the similar posts deal with other fish and not Corys. In the meantime, I lost two yesterday and another one tonight. I had a dozen, several of them regular breeders, and I am afraid I am going to lose more. Tonight I see two more with the beginnings of this strange "disease."
<I see.>
I have a 55 gal freshwater tank, a community of mostly tetras, Danios, and Corys. Ammonia is 0; nitrites 0; nitrates 160; ph 7.0; temp 72*. General hardness 180 and Carbonate hardness 0. <<I doubt this>>
<All sounds fine.>
I usually test with both test strips and chemicals in "test tubes" of tank water. About a month ago, I took the tank down about 1/3rd, cleaning the filter, siphoning debris from the gravel, etc. I waited and then
introduced some new tetras, Danios, and plants to the tank - would have been a few weeks ago. Threw about a pinch or two of aquarium salt in the tank. (Why? I don't know. It's the first time I've ever done that.)
<Indeed. Salt is much overrated and misunderstood.>
I have had fish for over 50 years (!) and have never seen my Corys get sick and die like they are now. I need your help!
I have attached two photos for you to see. This "disease" begins as a small spot of white (not cottony and not like Ick) then begins to spread like a blotch. It looks like the skin has died; it has turned white and
appears to be peeling like a sunburn would. I added a fungus treatment last night (Jungle "Fungus Clear" with Nitrofurazone, Furazolidone, and potassium dichromate). This afternoon, I took the tank down about 8 gallons, refilled with treated water (I use API "Stress Coat"), and added a large circular air stone. Everyone looked chipper and the Corys were swimming and playing, but a short while ago my "big mama" (the one in the photos) gave up and died. Please help me and my Cory "kittens".
<I think this is Slime Disease, also known as Costia. It's quite tricky to fix, but you should be able to find a medication sold in your area that works. Do note that while Formalin works, it's quite toxic to catfish (as
well as most other fish, to some degree or another) so isn't recommended. Raising the temperature to 30 degrees C can stress, even kill, Slime Disease, but this can also stress your fish, so be careful if you choose to use this method.>
Thank you so much! Anna
<Cheers, Neale.>

Re: Cory catfish with skin peel (RMF, Costia?) 1/23/11
Thank you so very much! Being Sunday here, we are out a bit today, but will stop at the pet store on the way home and see what we can get. The young man I spoke with yesterday at PetSmart has several large community tanks, and he didn't think it was fungal either. Man, I was hitting every resource I could think of during the past two days. As I said, yours was the best - I just didn't see this covered in a way I could readily apply it to my situation. Thank you so much for your quick answer!
<Glad to help.>
As there is Fungus Clear in there now, do I need to take the tank down by half or anything?
<Would do a water change, a good 30% or so, but otherwise there's no need to do anything special.>
I went back on your website and read a few articles about Costia (now that I know what I'm dealing with), and saw an article penned by Neale Monks.
Is that, perchance, you?
<Yes, indeed.>
Awesome!! (Not that it makes a difference to the discussion at-hand, but I am a Scot-Irish American - Clan Cameron.)
<Interesting to know.>
<Good luck, Neale.>

Re: Cory catfish with skin peel 1/24/11
Thanks again, dear Dr.! I stopped at PetSmart, got "Triple Sulfate"
(sodium sulfathiazole, sodium sulfamethazine, and sodium sulfacetamide). I mentioned to the lovely lady there that the Corys are vulnerable to salt (sodium.) Being that there is no caution note on the container, this is what she recommended. What do you think? Safe to use?
<Hello Anna. Corydoras aren't vulnerable to sodium as such, but to sodium chloride if the salt concentration is too high -- though contrary to what inexperienced fishkeepers believe, they aren't "allergic" to low salt concentrations such as those used to treat Whitespot. In fact the salt/heat method treats Whitespot on Corydoras safely and effectively. In any case, the product you bought should be safe to use because the sodium compounds are not sodium chloride and won't affect salinity. Cheers, Neale.>
Re: Cory catfish with skin peel 1/24/11
<PS. Do see Bob's comment on the Daily FAQs that water quality may be an issue, and worth reviewing. Excess mucous production can occur when Corydoras are stressed by their environment. The fact you reported zero carbonate hardness is surprising, and as Bob noted, unlikely; or if you really do have zero carbonate hardness, perhaps by using water from a domestic water softener, the resulting water is unhealthy and likely to experience very rapid pH changes (drops into the acidic range, usually) between water changes. Review this aspect too. Cheers, Neale.>
Re: Cory catfish with skin peel 1/24/11

Thank you so very much for this and the other note! I will go look at Bob's comments on the FAQs - but will have to do it on my lunch break as I am headed off to work this morning. I do not have a domestic water softener, and was using a test strip. hope that it was accurate, but I'll check that again this morning.
<Okeley dokely.>
I'll start the treatment on the aquarium this morning before I go. The package indicates 4 treatments with a 25% water change in between, an expensive treatment of about $30 so I sure hope it takes care of the problem.
<Yowsers! But as we point out repeatedly here, prevention is better than cure. Find fish suitable for your water chemistry, water temperature, and experience level. Kept right, fish rarely get sick.>
Worth it, though, if I don't lose any more Corys. Again, thank you so much!
<Glad to help. Cheers, Neale.>

Help with treatment plan for Platies/Corydoras 1/12/11
About a month ago Neale and Bob were able to provide me with some help regarding my 40 gallon freshwater tank that houses Platies and Corydoras and set me on a sane path after I panicked and made matters worse.
Originally, I was having issues with my KH rapidly dropping. Attached below is a portion of that correspondence in case it helps with history; however I believe I have sorted that out with switching to RO water and using crushed coral. I have been able to raise the carbonate hardness slowly and currently it is holding at 4
<Degrees KH, presumably, and good for a wide range of tropical fish.>
and my pH at 7.6.
<Also suitable for a very wide range of tropical fish.>
I also was able to get my ammonia and nitrites to zero (they had been spiking).
<Likely as water chemistry stabilised, water quality improved as well, the bacteria being sensitive to water chemistry changes, particularly pH drops.>
If you remember, I had done massive water changes and subjected my fish who had been living in a chronic acidosis state to acute alkalosis then acute acidosis (rapidly dropping pH) and back again. On 12/14 I stopped the massive changes and began the smaller 15-20% daily changes with R/O water buffered to raise the pH slowly. All of my fish had developed fin rot and mouth fungus at this point. I medicated with Tetracycline for 4 days and although I initially lost all my Platy fry under about 1 month old and my remaining Peppered Corydoras, my adult platies, fry over about 1 month old and Albino Corydoras survived and they rot cleared up and they started to heal.
Fast forward to 3 days ago (also current readings):
40 gallon tank
Live plants (multiple all true aquatics)
DH 10
KH 4
pH 7.6
AM 0
Nitrite 0
Nitrate 10
<All sounds fine.>
My Albino Corydoras spawned for the first time in a year or so and the Platies were very active and then I started noticing a problem - one Platy was hiding in a corner. At closer look, she seemed to have some gill damage and damage on top of her head and I attributed this to maybe not being able to recover from previous ammonia damage and the infection that followed the acute shifts in water chemistry. She died yesterday and 2 more adult Platies started hiding in a corner and another is not hiding yet but is not as active. One of the ones hiding has very red gills but the other two have no visible (to me) signs such as damage, gasping, red gills or spots. I thought maybe I hadn't treated them long enough and they still had some type of bacterial infection so yesterday I started Maracyn treatment because it treats for similar infections as the Tetracycline but doesn't turn the water that red color (and is not photosensitive).
<I would agree with you that a stress-related bacterial infection such as Mycobacterium could be responsible. These will create sores and cause infected fish to become lethargic, to breathe heavily, to hide away, and eventually to die. Dead patches of skin commonly appear as white flakes, much like sunburned skin on humans.>
Upon further observation, one other Platy that is very active has white spots flaked on its body. I looked at pictures today and it appears to be Ich. When the original issues with water changes and the fin rot were going on, about 4 of my adult Platies had this similar appearance but it seemed to clear with the antibiotic and I attributed it to being fin rot (this is my first time dealing with either condition).
<Finrot is generally very distinctive, beginning with cloudy patches in the fin tissue and pinkish blobs on the fins, the cloudy patches being dying cells and the pinkish blobs blood vessels congested with bacteria. After a few days the fins erode from the edges inwards, making the fin look ragged, often with the bony rays persisting for longer, the end result being a bit like a cobweb.>
Now through reading, it seems that ICH is only visible for one week and it's possible that they were suffering from both infections and ICH. I'm just not sure. I haven't introduced any new live stock to this tank in well over a year, but as with the bacterial infections, I now somewhat understand ICH is latent in tanks and ready to attack the weak.
<Ich/Whitespot can certainly trigger bacterial infections because the open wounds caused by the bursting white spots as they mature allow "bad" bacteria to get into the fish. On the other hand, stress can allow Whitespot and bacterial infections to become established independently of one another. So figuring out which came first is hard. By the way, there's very little scientific evidence that Whitespot can lie "latent" in tanks because the free-living stages need to find a host within a day or two, at least at tropical temperatures. What *may* happen is that low level infections persist unnoticed for months, and only when something goes wrong do the fish show high enough numbers of cysts to be obvious. Either way, treating proactively will break the cycle. Since the salt/heat method is harmless to fish, shrimps, filter bacteria and plants, this is a no-brainer for me -- treat with salt/heat, if only to cross Whitespot off the list of possibilities.>
These fish have been through HELL over the last month and I'm not exactly sure what I'm dealing with as so much has happened and I'm scared to continue the Maracyn or treat for ICH especially with the Corydoras in the tank. Can you advise the best way forward?
<Mycobacterium infections are essentially incurable, but Finrot and Whitespot should both respond well to prompt treatment. Do read up on these three, and act accordingly.
Thank you,
<Cheers, Neale.>
Re: Help with treatment plan for Platies/Corydoras 1/15/11

Hi Neale. I hope your weekend is treating you well. Thank you for all your assistance.
<Glad to help.>
I've read through the articles and I agree that ruling out Ich is a good idea; however '¦
I increased the temperature to 84 degrees over a day and a half and added the brine mixture (2 teaspoons of aquarium salt per gallon mixed in warm water put in the filtration flow path). I know you state the salinity is trivial for Platies but after adding about half the mixture, my Platies began to show sensitivity (hiding at the bottom and top of the aquarium).
<I doubt the salinity is the issue here. Platies can, do live in brackish water much more salty than this.>
Since they've been subjected to fluctuations in pH and ammonia and nitrite, unstable conditions, recovering from fin rot, could they just be less able to handle any change at this point?
<Seems unlikely. It's important to remember the difference between correlation and causation. Just because one thing follows another, it doesn't mean the first thing caused the second thing. If the Platies were sick or stressed already, then they might have gotten worse whether you added salt or not. Just make sure you're adding the right amount of salt, and that you're doing it in the right way. I'd turn the heat down a bit -- Platies come from quite cool habitats, and I'd not warm them above 28 C/82 F.>
The dilemma I face is that although they don't seem to like the salt, the one Platy who was hiding originally, came out today to swim for the first time in days today which is encouraging. While the other Platy with white spots has lost several of the bigger spots but is more lethargic which is encouraging and not so encouraging. My ammonia and nitrites are rising yet again (it seems the good bacteria doesn't like the changes either). The last dose of Maracyn was last night so I can up the water changes to reduce these levels more. I'm hoping without the strain of medicine and better control of ammonia and nitrites levels, the Platies will handle the current salinity better. I just want to make sure that my decision to not reduce the salinity is a good idea considering the Platies are showing sensitivity to it. I feel like we're (the fish and I) are damned if I do and damned if I don't at this point. I don't know which is the lesser of two evils.
<Would use the salt/heat method regardless.>
All but two fish are showing interest in food, the original sick one and another that I believe is severely constipated. I know I shouldn't be feeding them per the ammonia and nitrite, but I was trying to get the constipated one to eat a pea.
Also, in my reading of Ich, I've learned it can transmit on anything wet but I couldn't find instructions on how to handle transferring new plants into a tank per this possibility?
<Treat plants as potential sources of Whitespot. Quarantine any plants taken from tanks with fish in it, or for that matter from tanks likely to be on the same water circulation system in the pet store. Plants bought online from aquarium plant growers should be safe though.>
<Cheers, Neale.>
Re: Help with treatment plan for Platies/Corydoras 1/15/11
Okay, great. I've turned the heater down to 82 F. I didn't think the plant quarantine all the way through. I was thinking that you would never be able to tell if the plant had Ich on it but if quarantined, there wouldn't be a fish host to continue the cycle.
Once again - thank you.
<Yes, if the free-living parasites are unable to find a host within a period of time, they die. At tropical temperatures, that's about 24-48 hours. At room temperature, it may be several days longer. But I'd isolate plants for 7 days, at least, to be fairly sure they weren't carrying Whitespot parasites.
Cheers, Neale.>

Cory playing dead 11/5/10
Hi Crew,
Thanks for all the great work you do. I'm hoping you can help me again.
One of my four albino Corys has been behaving very oddly over the past few days.
He eats normally with the others each morning and swims around a bit but then spends much of the rest of the day lying on his back, appearing to be dead, until he is poked or touched by something. The first time I saw this I thought he was dead but when I went to net him out of the tank he immediately jumped up and started swimming around normally.
Each day since then I have noticed him doing the same thing but as soon as I put the net near him he rights himself and swims away. I saw him do the same thing when he was nudged slightly by another fish.
Is he really sick or is there some other explanation for this weird behaviour? The other three are behaving perfectly normally.
Thanks very much
<Mmm, well, Corydoras can be/act like real clowns at times, but laying on their back or sides is not normal, healthy behavior. I'd look about for an anomaly water quality wise, or at least act proactively and institute a series of daily partial water changes and gravel vacuuming. Bob Fenner>

Cory with hole in the head? (Bob, anything to add re: Red Blotch Disease)<<Nothing further>> - 10/12/10
Dear WWM,
I have a Corydoras julii with a hole in the head! It started out looking like a small scrape just above the mouth, but in the past week has eaten away at the flesh until I can see part of the "nose" bone. I also just
noticed a similar spot behind the left pectoral fin. These spots are flesh colored, with nothing in or on them from what I can see. The fish is breathing rapidly with pink gills, but otherwise eating and swimming fine,
although has slowed down a bit. The other fish are not affected by this.
This fish is in a mature (cycled since March) 10-gallon aquarium with four neon tetras, one black neon tetra, and a Bristlenose Pleco. I have had the Cory for a few months now. The water conditions are as follows:
Temp: 78 degrees, although with cooler weather it goes down a few degrees at night.
<Good; ideal water temperatures for most Corydoras are between 22-24 C/72-75 F. Keeping them much warmer than this will shorten their lifespan.>
pH: 7.8
KH: 120-180
Chlorine: 0
GH: 150
Nitrite: 0
Nitrate: 5-10
Ammonia I have not checked in a few weeks, but assume it is zero.
I have been very sick the past couple of months and have not been able to clean the tank properly, although I have more than adequate filtration (Whisper Power 20 and Aqua Clean 20 powerhead with undergravel filter).
I combed this site looking for answers and I didn't see any (not to say that they aren't there, but that I may have missed them.) I did find some helpful information such as proper diet for Corys and that they are social fish, so kept by themselves they may be stressed. I will remedy these as soon as I am able, but my main questions are 1) what is this? and 2) can I treat it? I have had this problem with Corys in the past and have just euthanized them because they're only a couple bucks and I was using them for "maintenance fish", not very attached to them - although I do like them.
Thank you for any help you can give me! Vanessa
<Hello Vanessa. It's unlikely your fish has Hole-in-the-Head. For whatever reason, this isn't usually a problem with "primitive" fish such as catfish or carp. My guess would be you're dealing with a bacterial infection. Some are opportunistic. A common problem with Corydoras is to keep them in tanks with gravel. While gravel isn't in itself dangerous, it does trap dirt and in the process cultivates bacteria. Should the gravel also be abrasive, there's a double whammy there because the abrasions on the belly, fins and
especially the whiskers become open wounds, and bacterial invade these and cause infection. Healthy Corydoras should have quite long whiskers: I've got some Peppered Corydoras in a tank with sand, and the bigger specimens around 5 cm/2 inches long have whiskers a good 1 cm/0.4 inches long, and distinctly tapered at the ends. Corydoras kept in tanks with gravel commonly have abraded whiskers that are much shorter, barely a few millimetres beyond the mouth, and the whiskers have blunt ends as well. If your Corydoras have whiskers like that it means the substrate is dirty and/or sharp, and either way, possibly both, your Corydoras are being subjected to low level bacterial infections. This isn't fatal, and many
Corydoras are kept this way and live for years. But it is a sign that conditions aren't 100% perfect so far as Corydoras are concerned. Cleaning gravel regularly helps a lot, and that usually means using a gravel vacuum.
Reverse-flow undergravel filtration will also help. But it should go without saying that smooth, lime-free sand is infinitely better for Corydoras than gravel, and no-one who keeps them in sandy tanks would dream of switching them back to gravel! Among other things, sand is kept clean by the catfish themselves, so bacterial infections are far less common. Now, the second possibility is the infamous Red Blotch Disease. This is a systemic bacterial infection that is usually caused by poor shipping but can come about through unhealthy aquarium conditions. A broad-spectrum antibiotic may help, together with, curiously enough, a teaspoon or two tonic salt per gallon, the salt in itself not being a cure but somehow reducing stress on the fish during the antibiotic therapy. Red Blotch Disease is less common today than it once was, aquarists largely understanding what it is Corydoras need to do well. But because you have had this problem before, my guess is that you are doing something wrong in the way you're keeping these fish, which is why you keep "failing" to keep Corydoras spp alive for long. Review the needs of these fish, and act accordingly. One last thing, should you need to destroy affected fish, be sure to review humane methods of doing so; some of the old school approaches, like laying fish on crushed ice, are now recognised to be neither fast nor painless.
Cheers, Neale.>

Corys Dying 9/26/10
Hello Crew, hope all is going well for you there. I have a question, please. I have a 75 gallon fw aquarium with 2 female gold gouramis and 6 assorted angel fish. I have had these for quite a while in addition to
about 10 Cory cats. Over a period of time some of the Corys have died off so I went a couple of days ago to purchase 4 green Corys which were bigger than the other assorted ones I already had in the tank. After I got them home and acclimated them they all seemed to be doing well and swimming around the tank. Then over the next 2 days when I woke up and looked in my tank all of my Corys were dead. Some looked chewed up and some had their tails bitten off (at least it looked that way). Also I am missing a small angel fish which I cannot find anywhere. I don't know if that is related in any way but I would like your opinion on what might have happened please. Thank you,
<Hello James. Do understand most Corydoras prefer quite cool water, 24 C/75 F being the tops for most species, and if kept substantially above that they will not do well. The exception is Corydoras sterbai, which is fine up to 28 C/82 F. Corydoras are also obligate air-breathers, and they need to be able to swim to the top of the tank easily. If the tank is much deeper than, say, 45 cm/18 inches, they may find it difficult to do this. A lot depends on the size of the Corydoras, water current strength, resting places between the substrate and the surface, and how aggressive the midwater fish are. But it may be a factor. Thirdly, Corydoras depend upon the bottom layer of water being of good quality. Make sure the filter is
working properly, and that there's a good, strong current along the bottom of the tank. Canister filters and undergravel filters generally provide this without problems, but hang-on-the-back filters might not if the inlet pipe does go right down to the bottom of the tank. Adding an airstone or two at the bottom of the tank will help significantly by creating an upwelling flow of water that draws bottom water to the top of the tank, and this in turn means surface water will be pulled down to the bottom.
Naturally, check water quality and water chemistry more generally.
Corydoras need 0 ammonia and 0 nitrite. They aren't fussy about water chemistry, but it should at least be stable, so pH changes should be minimal. Something in the range 3-15 degrees dH, pH 6.0-8.0 is fine.
Finally, Corydoras may be stressed by copper and formalin based medications used to treat Whitespot and the like. Because you've also lost an Angelfish, I'd be tempted to focus on water quality above all others, and check the filter is properly configured, stuffed with the right sort of media, properly maintained, and adequate to the numbers of fish being kept.
I'd review water change frequency, tending towards more, small water changes rather than big, infrequent ones. If you can change 10% every 3-4 days, that'd be ideal, at least for a month to see if things settle down.
Review the amount of food being given, and check the Corydoras are getting enough to eat, e.g., by offering 1-2 algae wafers every couple of nights.
Cheers, Neale.>
Re: Corys Dying 9/27/10

Thank you.
<Happy to help. Cheers, Neale.>

Itching Cory Catfish 7/10/10
Hello again,
<Hello Brian.>
You've been helpful in the past when I had questions about my first aquarium and some stocking advice for my second, so thank you.
I did want to ask something about 6 new Panda Cory Catfish I added a couple weeks ago.
<A low to middling temperature fish; don't keep warmer than 25 C/75 F.>
They are the newest inhabitants to a ~4 month old cycled aquarium. They share a 46 gallon with a school of 9 Harlequin Rasboras, 6 Cherry Barbs, 3 Oto Catfish, and one last cycling Platy that's been tough to net out.
<OK. These should all do well at 24-25 C/75-77 F. Any warmer will stress the Platy, Otocinclus and Corydoras.>
Anyhow, as of yesterday morning I noticed one of the smaller Cory catfish do a few quick darning motions in the gravel on his side while scavenging for food. He only did it a couple times until the others joined him to start eating the pellets I dropped for them. I looked at the fish but didn't appear to have anything on his side, nor any discoloration (nothing I can see), and he's been actively swimming and searching for food as always. Then this afternoon, about an hour after they finished eating any dropped pellets, I saw the same behavior again; 2-3 quick darts in the gravel, and only in the gravel not on the decorations where I normally feed the catfish. It is a normal aquarium gravel, black, not sand nor a fine gravel that I've heard Cory catfish like to dig into.
<Hmm... "like" is perhaps not the right word to use here. Corydoras kept in tanks with gravel, especially sharp gravel, suffer from abrasions, in particular to their whiskers. You can instantly spot Corydoras kept in tanks with gravel because they have almost no whiskers, whereas those on Corydoras kept in tanks with smooth silica sand have whiskers that are very long, half an inch maybe. It's quite striking. While the missing whiskers aren't fatal, they do indicate that the fish are being damaged and vulnerable to secondary infections, which is a warning sign that all is not well.>
I still cant see anything wrong with him nor any of the other fish, including any of the other catfish. He still swims actively around and all over the decorations/plants as usual looking for food, so he doesn't appear sick.
<Flashing can be a variety of things, but the most common are these:
ammonia/nitrite above zero; Velvet; and Ick, in that order. Just because you can't see any other Velvet or Ick on the fish doesn't mean there isn't any in the system. Both these parasites go for the gills first.>
I guess I'm just curious if this is some kind of feeding behavior, like trying to scare up any buried food particles,
<No, Corydoras don't do this. When feeding on sand they plough their heads straight down, and spew the sand through their gills. It's fun to watch, and no-one who has kept Corydoras with sand EVER goes back the gravel. I'm not saying you can't keep them with gravel, but it's far, FAR inferior in terms of fun, both for you and the fish.>
or something of the sort and nothing to worry about, or if it's some sign of a disease that just isn't visible?
<Likely so.>
Water conditions for the past few weeks before adding the Cory catfish, and still...
pH ~7.5
ammonia 0ppm
nitrite 0 ppm
nitrate ~5ppm (weekly water changes)
<All fine.>
temp ~79F (extremely tough to keep any cooler in summer in Florida w/out a chiller)
<Will cause problems if it stays this warm. Do increase evaporation and try floating litre-sized blocks of ice in the aquarium.>
hardness ~200KH ~150GH normal for this area (but no problems with Platies and Cory catfish in a different tank for over 1 year)
<Indeed, water chemistry isn't a major problem for Corydoras, and Platies obviously prefer medium to very hard water.>
Thanks again,
<Cheers, Neale.>

Quick question about Corydoras catfish 5/11/10
<Hello Judy,>
I was just wondering if it is harmful to keep just one Corydoras catfish?
<"Harmful" is a difficult word to use here. Yes, these are schooling catfish, and if kept singly the loner will be stressed and therefore more likely to get sick.>
I have a 10 gallon tank with 6 Neons and one Corydoras. Is one alone stressed out since they are so social??
<Yes. Get four more of the same species!>
Thank you!
<Cheers, Neale.>

Corydoras paleatus, fat behavior 5/5/10
I have 5 Corydoras paleatus in a 160 litre aquarium with the temperature at 22C.
<Very good.>
They've all lived in this aquarium for over a year and spawn regularly.
<As is their wont, when happy.>
The ammonia and nitrite are both 0 ppm, the nitrate is 10 -- 20 ppm and the pH is 7.2.
I change about 30 -- 40 % of the water per week. This morning I have noticed one of the females is acting a little strange. The best way I can think to describe it, is she is looking a little 'floaty' in that she's not resting on the bottom or looking for food but is instead floating just above the substrate.
<Yes. Does happen. Sometimes means she's swallowed too much air, but could also be simple indigestion or constipation.>
She is also going to the surface for air a lot more than usual but when she returns to the bottom this air seems to be being expelled quickly from what looks like her anus, meaning a couple of minutes later she returns to the surface for more air and the process repeats itself.
<I see.>
I can't find any information on the web about whether or not this is a problem, perhaps because I'm not sure what I'm looking for.
<To try raising the water temperature a bit for a few days, to 25 degrees C, and see if that helps. You could also add a little Epsom salt to the water, 1-3 teaspoons per 20 litres, as this has a mild muscle relaxing action that works like a laxative. It won't stress the fish at all, but if they have blockages of one sort or another, it can help.>
One of the other females is looking particularly fat this morning and I think they are ready to spawn again.
<May well be.>
Could this strange behaviour be anything to do with spawning or should I be worried?
<Wouldn't be unduly worried. Observe, act as mentioned above, and only worry if she doesn't improve within a few days.>
I am concerned something is causing pressure inside her which is causing the air to be expelled so quickly.
<Possibly, but I can't think what.>
I hope I have provided enough information for you to be able to give advice, if there is anything else I need to provide, I'd be happy to.
<Good luck, Neale.>

Cory Cats white balls on dorsal fin -4/7/10
I have a 55 gallon with four guppies, seven platys, eight black skirt tetras,
<Gymnocorymbus ternetzi, can be persistent fin nippers, and fin nipping leads to open wounds, and open wounds become infected...>
a Pleco, and two emerald Cory cats.
<I assume you mean Brochis splendens. Why just two? These are social animals; groups of five or more, please! Like Corydoras, Brochis are totally different fish when kept correctly, and fish that are less stressed are less likely to become sick. In a 55 gallon tank there's no excuse for not adding a few more Brochis splendens.>
My water conditions are 0 ammonia, 0 nitrate, 20ppm nitrate, 7 ph, and a temperature of 78. I recently (about a week ago) just got done fighting off Ich using heat treatment--I did not use salt in addition to heat--and haven't had it recur since returning the temperature to 78. I also perform 25% water changes weekly.
<By itself heat doesn't kill the Whitespot/Ick parasite, so you're deluding yourself here. The point to raising the temperature is that this speeds up the life cycle of the parasite, causing the white cysts to open more quickly. That's essential because Ick medications ONLY treat the free-living infective stages, not the white cysts themselves. So, the parasite is probably still in there. Just because you can't see it, doesn't mean the fish aren't carrying a low level infection on their gills. Plus, the wounds created by Ick can become sites of secondary infection.>
About two days ago I noticed that both of my emerald Cory cats had a white tuff/ball looking thing on their dorsal fin where the fin meets the body (on the side nearest to the tail). I thought at first it might have been a fungal infection, but I found it odd that they both have it on the exact same spot and in the exact same size. I didn't recognize it on them before, however, I might have missed it. Ever since Ich took over, I have been paranoid about inspecting the fish each day, more than I did before. Is this most likely a fungal infection or is this a normal part of their body?
<It's a disease of some sort. Likely Fungus or Finrot, though it could be Ick if about the size of a salt grain.>
<Do read, understand the why fish get sick and how to treat them. Paranoia is pointless if you don't prevent or medicate diseases properly. Cheers, Neale.>

Sick Cory cat 3/25/10
I have a question about a sick Peppered Cory cat I have. This morning (after a water change last night) I noticed a large white spot on the back of his head and I'm not sure what it is. I was unable to find anything like it in the archives. He is in a 20gal tank with one other peppered and a skunk, along with 20 Frontosa fry. They measure inch or less. I am waiting for my 72 bow to cycle before I put the Frontosas in there. The tank has been set up for 2 months now, the water is clear and I do 25% or more water changes every Wednesday and on the weekends. I don't have any equipment to test the water to get the exact numbers but I know its pretty good. Do you have any
ideas as to what it might be? Is it possible that I bumped him with the cleaning hose and that would cause a white spot? Please advise
<Hello Paul. Without a photo, it's difficult to be sure. Do start reading here:
This page has a dichotomous key that helps to separate the most common problems. Tiny white spots can be Velvet or Ick, while white patches may be Finrot or the start of a fungal infection. Damaged skin is often white, and
heals by itself under good conditions, but excessive patches of mucous, which tend to be off-white to grey rather than bright white, imply a reaction to poor environmental conditions or certain parasites including Costia ["slime disease"]. Be open minded; you idea of "good" conditions may not be what I consider good, or for that matter what Finrot bacteria and happy catfish consider good! Cheers, Neale.>

Sick Cory Cat - Please Help 1/21/10
Hi Crew,
Sure hope you can offer some suggestions. I have a sick Cory cat and am not sure what to do.
<Will try my best.>
20 gallon planted community tank: 0 Ammonia; 0 Nitrites; Found last week my Nitrates went to 35 (!), down to 20 now and I'm working on that (my tank is typically at less than 10..
<In itself, nitrates of 35 mg/l aren't likely to cause sickness. Indeed, the tap water in many parts of England has 50 mg/l nitrate! Cichlids and certain other fish are very sensitive to nitrate, but catfish on the whole are not.>
I think excess shrimp pellets had caused this spike as Nitrates).
Temp 77,
<Far too warm for most Corydoras. Almost all species -- the notable exception is Corydoras sterbai -- prefer (need) quite cool water, about 22-24 C (72-75 F). The warmer you keep them, the less healthy they will be.
Obviously you need to choose tankmates that also like fairly cool water; Platies, Neons, Danios etc are all ideal.>
Weekly water change/vacuum.
Fish include 1 swordtail, 1 Farlowella, 5 tetras, 1 powder blue Gourami, 5 little Otos, and several Corys of a few different species.
<Again, another stress issue is social requirements. Note that you should keep at least five specimens of each Corydoras species. Having five specimens of five species won't make them feel particularly happy, and an unhappy fish is a stressed fish, and a stressed fish can easily become a sick fish.>
PH around 7.0, and the water is hard, but I have had Corys for a few years and have never had a problem (I believe they like softer water?).
<Actually doesn't matter much.>
Nothing new in the tank in recent months
Not sure what species this sick Cory cat is...he looks similar to a black fin Cory, though not identical. He is the smallest in his group of four, and I've had all four for a year and all have been very well.
Not eating for at least 4 days, no interest in meal time
Isolated from others at times, but not hiding
Sleeps on leaf in the middle of the tank
Goes to the surface more frequently than normal for air, then swims back down
Clamped fin
Barbells look much shorter than usual but I will check on that again tonight with a flashlight
<Erosion of the barbels is a classic sign of secondary bacterial infection.
In short, a dirty or abrasive substrate damages the barbels, and bacteria set in. It's essentially Finrot. Corydoras do best in tanks with [a] smooth silica sand substrate; and [b] strong water flow along the bottom of the tank. Departures from these two criteria increase the risk of barbel erosion. The classic causes are gravel rather than sand; sharp sand (e.g., Tahitian Moon Sand) instead of smooth sand; and a filter that doesn't have much water flow along the bottom.>
* He is turning a very dark colour, not quite black but close to it. This is what first alerted me to a problem, over a week ago. This colouration is uniform throughout his entire body. No signs of any fungus, and swimming is still strong All other fish are doing very well
I know Corys like low nitrates so I did a 20% water change on Sunday, and have since done two 5-10% water changes, in case the nitrates at 20 are making him sick.
I am wondering if I move him to a 10 gallon hospital tank, with a fresh vacuum and water change, will that cause too much stress being in there alone?
<Yes, is very stressful.>
Or would he have a better chance of recovery staying where he is (perhaps with a larger water change?). And if his barbells are disappearing, are they gone for good?
<No, will grow back.>
Really not sure what to do and am open to all suggestions. Thanks in advance for the help, and for this amazing web site!
<Do review the needs of Corydoras, and act accordingly. If you suspect Finrot, treat as per Finrot, but take care to avoid copper or formalin, as these can be highly toxic to catfish generally. Cheers, Neale.>
Re: Sick Cory Cat - Please Help <ADDITIONAL INFO>
Hi again,
I checked in on the little Cory in better light, and definitely his barbells are nowhere near the length of the other Corys of the same species. They are either very short or gone. Is there any hope for him?
He is more listless tonight that he was yesterday.
<Check/improve water quality; treat as per Finrot, avoiding copper and formalin based medications if possible.>
No fungus or anything present around his mouth.
I also did another 10% water change tonight and nitrates are still around 20 (out of the tap they are close to zero).
<Do read previous e-mail. Cheers, Neale.>
Re: Sick Cory Cat - Please Help
Hi Neale,
You've been most helpful, as always. I learn so much from you and the crew.
<Glad to help.>
Most reading I've done on Cory cats says 72 - 79 is ideal, so I didn't realize that 77 was too warm.
<Depends on the species. Many general web sites will give this sort of range based on no particularly deep knowledge of these catfish. But if you read books on catfish, or visit sites like Fishbase or Planet Catfish, a different conclusion will be reached. By far the vast majority of Corydoras come from relatively shallow water where temperatures vary but are often cool. Some species, including Peppered Corydoras and Bronze Corydoras, actually like fairly brisk conditions, down to about 18 C in winter (68 F).
The infamous Bearded Corydoras (technically, Scleromystax barbatus) wants things even colder, around 15-18 C (about 59 to 68 F), all year around.
Most of the other species are happy at middling temperatures, around 22-24 C, but above 24 C (75 F) your list of happy Corydoras gets very short.
Essentially just the one species in terms of what's available, Corydoras sterbai. This hothouse flower has become known as the "Discus Corydoras" simply because it's the only one happy at the 28 C (82 F) that Discus, Angelfish and other warm water tropicals need.>
I will definitely start to slowly reduce the temp of the tank by a few degrees, over time. Thanks for that info.
<Make sure your other fish will be happy.>
Regarding treatment for fin rot, is there anything you suggest (I'm in Canada) that will not harm my Farlowella? I also have been graced with a 1/2" "surprise" pond snail and am hoping none of these critters will be harmed if I am treating my main tank for fin rot.
<I have no idea what's on sale in Canada, I'm afraid. Here in England, the product I rely on for Finrot is called eSHa 2000, and I've always found it safe around delicate fish such as catfish and puffers. Provided you avoid copper and formalin/formaldehyde (look on the ingredients list) you should be okay.>
You also mentioned strong water flow along the bottom...would it benefit this tank to add a bubble wall at the bottom? I have one that I keep in my 10 gallon (currently empty).
<Sure. Worth a shot.>
Thanks again, Neale!
<Cheers, Neale.>
Re: Sick Cory Cat - Please Help
Thanks for the education, Neale! I will expand my reading. Much appreciated!
<Always glad to help. Cheers, Neale.>

Leopard Cory missing an eye 1/9/10
Tonight about an hour after I fed my fish I noticed that one of my leopard Cory's missing an eye. Tank mates include other leopard Cory's, Kuhli loaches brilliant Rasboras and a Opaline Gourami and a black ghost (he is about 4-5 inches. Just taking a wild guess that the only fish that might of gone after him would be the BGK?
<Is the most likely suspect, yes>
My other possibility guess is that the Cory may have gotten in the BGK's way and got knocked into each other. It seems that from reading other posts on here that ... in general.... BGK's don't go after Cory's????
<Not generally. The loss of the eye may be attributable to a physical injury... the Corydoras "bumping" into something sharp... This fish can still live a good life w/o the one eye>
Anyway I don't know if I did the right thing but I took the Cory out of the tank and put him in a big bowl for the night. If he makes it through the night should I put him back into the tank?
<I would return this fish to the main tank pronto/right away>
Or if I do will his missing eye injury get infected and affect the rest of the tank?
<It will not>
Whatever advice you can give will be much appreciated.
Thank You
<Welcome Joe, Bob Fenner>

Re: Vacation question. Corydoras hlth. 12/23/2009
Thank you for the quick response. After receiving your email I noticed another issue with one of my Corydoras. There is a small white spot at the rear of the dorsal fin near the body. I tested the water and nothing has changed in terms of quality that was reported in my last email. The tank is 78 degrees.
<Much too warm for most Corydoras; with the exception of C. sterbai, most of the traded Corydoras are happier (i.e., healthier) kept between 18 and 24 C (68 to 75 F) depending on the species. Corydoras paleatus and Corydoras aeneus for example like the cooler end of this range. Many hobbyists keep them much too warm, as they often keep Neons, Danios, Rosy Barbs, Platies, Swordtails and many other tropical fish much too warm.
Choose fish that enjoy the same temperature range, and keep them at an optimal temperature.>
Having nothing new added to the tank in about 4 months I am hoping if you can tell me if this is Ick or something else.
<"Something else". This is a tumour of some sort, likely benign, or else the catfish equivalent of Fish Pox (which carp get) or Lymphocystis (which is mostly found in Perciform fish like cichlids). In and of itself, not life threatening, but a good indication the fish's immune system has been weakened by chronic exposure to the wrong (or poor) conditions. In the case of Corydoras, lack of water circulation at the bottom of the tank, as well as a substrate that isn't routinely cleaned, are both examples of sources of stress. Whether a tumour or a viral infection, no cure as such, simply time, a balanced (vitamin rich) diet, and good water quality.>
none of the other fish have any noticeable spots. I had to take the pictures from above as the Corys never seem to stop moving in the tank in their never ending search for anything edible.
<Please do observe our "house rules" re: images -- to avoid filling our 10 MB e-mail inbox allowance, keep individual images to 500 KB or less... yours were 5 MB! If someone else did this on the same day, other folks
would have their messages bounced back.>
Thanks again,
<Cheers, Neale.>
RE: Vacation question.
Thank you again I will try to drop the temp a few degrees.
<Do check the other fish don't mind. As I mentioned, many fish like relatively cool conditions. But other fish, notably Ram Cichlids Cardinals, Mollies and Angelfish, will object strongly to being kept cooler than they prefer.>
I vacuum the gravel once a week and have good circulation down at the bottom.
Have a wonderful holiday.
<I intend to! Enjoys yours. Cheers, Neale.>
Re: Vacation question.
Oh and sorry about the large file size
<No problems. Just remember for next time! Cheers, Neale.>

Bronze Cory Help!!! 10/17/09
First off I want to say that your site has been a great deal of help. As a first time fish owner I have used your site as a resource in having a happy and thriving tank.
<Thanks for the kind words.>
I have had my 35 gallon fresh water tank since end of April. I followed the beginner guidelines in circulating the tank before I put in any fish. Right now I have four Rosey barbs, a rainbow shark, Pleco, and three bronze Corys and so far haven't had any problems until today.
<Sounds an interesting mix. While the Rosy Barbs and the Corydoras both appreciate somewhat cool water, Rosy Barbs can be "fin nippers" and work best in large groups (six or more specimens, a mix of males and females) so they busy themselves chasing one another around rather than other fish.
Rainbow Sharks can be feisty, and the Plec will get far too large for this aquarium. So you will have some problems to fix before too long.>
Icky, one of my Corys went missing this week. I searched the tank and he was no where to be found. Today, we did a 60% water change and put in some Columbian drift wood. After picking up a rock that was, until today, thought to be a safe tank decoration - out zooms icky the Cory catfish looking pretty rough. For the first couple of minutes of being free from his confines he was laying on his side. After a little more time passed he's sitting in his natural stationary, but upright, position. It looks as though the barbs made a meal of a few of his fins, and he has several spots that have been worn from trying to wiggle out from beneath the rock.
<Yes: Rosy Barbs will indeed nip at fish. For whatever reason, Corydoras are "sitting ducks" where nippy fish are concerned. I find that whereas Plecs and Synodontis keep out of the way, every time I've kept Corydoras with, say, Puffers or Ameca splendens, they've had their dorsal fins nipped.>
It looks as though he's on the track of pulling through, but you never know with fish. Do you have any advice on how to treat this situation?
<Beyond clean water, I'd not do anything else apart from separate them.
Corydoras fins heal very quickly, and like many catfish, they're likely to react badly to copper or formalin, so I wouldn't use either unless I absolutely had to. So move the school of Corydoras to an aquarium of their own, something 20 gallons upwards, and let them settle down and be happy.
Rosy Barbs sound like a poor choice of tankmate here. You might even get rid of the Rosy Barbs; when all is said and done, they're big fish (up to 15 cm/6 inches) not suited to 35 gallon tanks.>
I'm worried that icky may not make it.
<Cheers, Neale.>
Re: Bronze Cory Help!!! 10/17/09

The Rosey barbs and the Corys get along, they really mind to themselves or get chased every once in a while by the shark. Luckily the only issue we have had with the barbs is that they chase and nip at each other.
<What they do. If kept in large groups, six or more, and ideally more females (yellow-green) than males (pink) then they tend to settle down. In the right tank, a spacious subtropical system, they're superb fish.>
We are fairly certain that the reason why icky the Cory cat has had a good amount of his fins nipped off is because he was literally stuck under the rock but the barbs could still get to him.
<Whether he got stuck under the rock, or was hiding to avoid being nipped, is difficult to answer. Both explanations are possibilities.>
Right now the rough looking Cory looks as if he is acting normal, but he really looks rather rough.
<Indeed. Usually, Corydoras heal very well. The common species like Bronze and Peppered Corydoras have become so popular precisely because they are so durable.>
We know of the issue with the Pleco out growing our tank. We have a home for him when he gets big enough in a 300 gallon brackish cichlid tank at a restaurant that we frequent.
<A home perhaps, but a bad one. Plecs ARE NOT brackish water fish.>
There is also a home for him at the Koi fish pond at the local botanical gardens.
<Unless this Koi pond is somewhere tropical, then that's not an option either. These fish die when exposed to water temperatures below 20 C (68 F) for any length of time. In the US for example, Southern Florida is the only place where these fish are likely to survive outdoors in an unheated pond.>
We've made sure that he will have a place to go when we can no longer care for him.
<Hmm... not impressed so far with the options.>
Looks as if we'll just have to wait and see how icky fairs. Keep your fingers crossed for us! Thanks for the tips!
<Happy to help.>
Also, about the barbs - we'll definitely consider trading them in for more suitable tank mates. Any recommendations??
<Depends, and the thing with many schooling fish is that if you don't keep enough, many species can become nasty, even Danios. One of the single best schooling fish species in the trade is the X-Ray Tetra (Pristella maxillaris). This species is very hardy and very peaceful; it is also rather pretty. I don't care much for the albino form, but it exists if that sort of thing amuses.>
Much appreciation, Kristin
<Cheers, Neale.>

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