Sick corys, nothing helps

[Corycory]

Hi all, I am struggling to cure my corys from unknown disease.

I have a tank on which I changed the substrate to JBL aquasoil capped with JBL black sand. 2 months after that all fish got sick, including the ones I moved from a still healthy tank. I suspected it's something to do with the soil and sand. It wasn't supposed to leach ammonia but if it did, it was never detected and it didn't change the Ph.

At the moment, I have a pygmy cory with a white edged fin and rotting tail. There's a video below of it. Then I have 2 corys with a strange white growth just under the dorsal, oval shaped, milky colour and on the same spot on both corys, again pictures below. Almost all corys have one or two missing barbels. One of them had a rotting tail with white streaks, aka fin rot but it isn't there anymore. It is just this tank. My other corys are fine in the other tanks. I actually topped up the tank with white plain sand as they seemingly didn't like the other one.

When I first noticed, there was one pygmy with damaged fins and a sterbai with missing barbels and a pinkish curly growth on its head. I had no meds besides the useless melafix so I decided to take them out and put them in a temporary tank with cycled media and some melafix. I did put some on the wounds with a cotton swab as well. I found the corys dead no more than 12 hours later so that was a bad move from me.
Afterwards I treated the entire tank. I received kanamycin medicated flakes so I fed them twice a day for 10 days with no luck. Then I treated with kanamycin sulfate(kanaplex) dosed directly in the water for full treatment. The white growths seemed to disappear but the pygmy cory had no change. I just followed the instructions which said treat every 2nd day for 3 treatments max with water change on each so I don't know if that was enough. 2-3 days after I stopped the treatment the white growths appeared on the same place or at least were big enough to see again. Then I treated with interpret Antifungal N.8 med which is one treatment for 7 days. It seemed that the white growths got smaller again but are still there, the pygmy got way worse all of a sudden. Then I bought Tetra General Tonic but since I was afraid it would damage the filter and tank, I put the pygmy cory in two dips, 15-20 min of treble the dose, it did nothing at all.
And obviously, the missing barbels problem has not improved one bit but I don't know if that will ever happen.
I don't know what it is, there isn't any flashing. They have good appetite and come out for food except for the sick pygmy maybe but they never fought for food with the rest. They were very happy when I had gravel there. Most corys hide and are visibly stressed as they get spooked very easily for some reason and bump around. I need to be very careful but they get excited when I open the lid thinking its food time.

I don't know what to do to help and I really want to help the pygmy cory which is the worse affected. This has been going on for a long time now.
I am now doing daily 50% water changes until I figure what elese to do.


Here is the video and pictures of my poor corys

[papwalker]

High nitrates?
AFAIK this sort of thing is nearly always a water quality issue.
Four weeks seems a long time for symptoms to manifest from substrate issues.
I am surprised you suspect ammonia from substrate unless it has a very high bioload. The question then becomes why is your filter not cleaning this ammonia out? Since you didn't measure any there was probably none.

I'm not convinced these mickey mouse soils are the right thing for Amazon basin fish anyway.

If I suspect fungal / bacterial issues like this I do 15% W/C daily and use a little Seachem prime and stability and if I'm really worried a dose or two of StressGuard. I might sneak the temp up a little.

I don't further disturb the tank.

A mixture of Hikari frozen brine shrimp, carnivore pellets and their regular pellets. Top notch food to assist immune systems.
Then I wait it out.

[Corycory]

The reason I suspected undetected ammonia from the substrate is because soil releases ammonia when first put in a tank due to high organics. My TDS went well higher than normal and it took quite a while to bring it down via water changes but by that time the fish were sick. The highest nitrAtes I measured during that period was 40ppm and that's normally high for this tank as it always was below 10ppm, but those tests are unreliable. Now it's barely measurable after so many water changes.

Whatever happened after I changed the substrate, I do suspect it caused bacterial issues directly or indirectly, however it's hard stopping it now. The medications I tried aren't doing much. I've been doing 50% water changes daily since I saw the problems, and while medicating, whatever the meds suggested, which for kanamycin was every 2 days, for interpret I had to leave the tank for week without. But before and after, I did massive water changes and still doing them each day. I use Seachem Prime for dechlorinator. They've been eating NLS community, NLS thera A+, hikari sinking wafers, sera bottom feeders, NLS thera A+, tetra colour+, blood worms and mosquito larvae. I really don't think it's a diet problem. I've got lots of different foods than that as I have a few other tanks. The fish eat well, aren't listless, but on the contrary. The have a nice colour and are healthy looking other than the stuff I described and missing barbels on most.
I don't have Seachem stability. What is it beneficial for?
I've got Seachem Purigen in the filter and carbon since I medicated. If it matters as well, the tank is way overfiltered. I've got two filters running turning the water volume 18 times an hour and its been like that for 2 years. And I normally do 50% water change weekly without fail but for the last month and more i've been doing water changes like a lunatic as described above.

I'm not convinced these mickey mouse soils are the right thing for Amazon basin fish anyway.

I don't think so either. The fish went into hiding ever since I put it in but I thought it's the different layout.

[Corycory]

I forgot to ask. Why raise the temperature if its bacterial infection? Wouldn't it make that pathogenic bacteria multiply faster? Or is it going to run its life cycle faster and thus help?
Temp is 24-25C normally.

[papwalker]

A lot of aquatic bacteria don't like high temps (Myco being one) although sometimes there is an initial benefit to the organism, eventually the higher temps up-regulate a fishes inflammatory and immune response.

Finn, J. P. and Nielsen, N. O. (1971), The effect of temperature variation on the inflammatory response of rainbow trout. J. Pathol., 105: 257–268. doi: 10.1002/path.1711050404

[papwalker]

Regarding barbel erosion and high bioload substrate read this...
http://www.skepticalaquarist.com/corydoras-genus

Also consider that the river bed in the natural habitat of many corys is not a productive medium for plants. It is nutrient poor. Even in the flooded forests the soil is nothing to write home about.

Regarding substrate colours etc.
It occurs to me that corydoras markings have evolved as a form a camouflage in relation to the substrate, probably more so than recognition colouration. I have always used substrate that matches the colouration of the fish. They tend to disappear when viewed from above.
Whist I can offer no proof, I suspect the exposure of fish on a mismatched substrate may be a stressor and lead to timid behaviour and a reduction in health.

[Corycory]

Thanks papwalker.

How high should I raise it for corys and for how long?

[Corycory]

In regards to the substrate, it is now capped with normal sand and they are a bit happier compared to before. All the fish will be moved to 100G tank I am setting up at the moment(its cycled already)Its mainly for all my corys but unfortunately its going to have soil capped with sand again, although the soil this time will definately not leach anything toxic to fish as I've been mineralizing it outside the tank for weeks( soak and dry cycles)
And the sand will be normal, not that black volcanic stuff I initially put in this tank.

However, I want them healthy first as its hard treating a 100G

[Corycory]

Regarding substrate colours etc.
It occurs to me that corydoras markings have evolved as a form a camouflage in relation to the substrate, probably more so than recognition colouration. I have always used substrate that matches the colouration of the fish. They tend to disappear when viewed from above.
Whist I can offer no proof, I suspect the exposure of fish on a mismatched substrate may be a stressor and lead to timid behaviour and a reduction in health.

Sorry, I missed this part.
Do you refer to the white sand?
They actually got sick after I put the JBL black sand(previosly the tank had river gravel) and I only changed to white sand after I noticed the missing barbels. I use this white sand in two other tanks with 0 issues, including their same colour siblings and their parents. My corys are an accidental hybridization between my albino and gold laser corys.

[Corycory]

Regarding barbel erosion and high bioload substrate read this...
http://www.skepticalaquarist.com/corydoras-genus

I've read this article many times before via a search. If its nitrates, they could have been exposed to 40-ish max but for no longer than 2 months on and off. this should no longer be an issue.
I don't think its flukes because I thought they would flash/scratch themselves but they don't at all but then again I am not sure what the symptoms are.
If its enviromental and water quality was bad, then thats the easiest to fix and it was the first thing I made sure is ok, hence the daily 50% water changes since noticing the problem.

[papwalker]

Thanks papwalker.

How high should I raise it for corys and for how long?

not above 30 for a few days. It's a little dependent on the species but most should handle 30 without too much stress.

Scaring and erosion to fins and barbels can be long-term to permanent. So a fish may look infected when it's not.
I have one little Sterbai I let get chilled. He still looks ragged after 8 months but seems fit enough.

With the water changes be careful you're not bouncing temps and chemistry around too much. I tend to do less and often.

[Corycory]

With the water changes be careful you're not bouncing temps and chemistry around too much. I tend to do less and often.

No, i add temperature matched water. I've always done 50% water changes and never had a problem or sick fish, and even my shrimp are breedind like crazy and take no notice. I think its only dangerous when you let the tank water shift too much from the tap via irregular and small water changes. I keep the TDS of the tanks close to the tap like that so there should be no stress.
I'll turn the temperature slowly up.


Edit: I saved a lonely cory once from a barb tank in the fish shop. He grew his barbels back along with his damaged fins.
On a side note one of my sterbais that definately had no barbels, has grown them all back so some meds did something I guess. At the moment, I don't know if you've heard of treating fish like that but the last few times I let the fish sit in non-dechlrorinated water for 15min after the water change. Its an advise I got once from a very experienced fish keeper. Its been 3 days only I've done this and the pygmy cory, for good or bad, has lost the white edge on the fin for the first time.

[papwalker]

A few people treat with chloramine. My concern is that it may kill the bacteria directly on the fish but you need to then put it into a completely clean isolation tank. No point throwing it back in where the organism is still present.
To my mind it is all a bit stressful. Like chemo, and I suspect stress is the major cause of initial infection. But if it's working then keep going.

BTW
Chloramine-T might be a better alternative than tap water.
http://www.koivet.com/a_chloramine_T_ba ... s_koi.html

[Corycory]

I've been doing this directly in the tank, not outside. That's how it should be done from what I understand. So if the chlorine is doing something, then it's disinfecting the whole tank at the same time. The fish don't look bothered one bit to be honest. I use the time while the filters are off and to feed them and observe them and they are busier eating than worryng they are having a chlorine bath from what I can see
If I can manage to kill what's on the fish to help them feel better, then they maybe capable of fighting off any other pathogens themselves. Plus the large daily water changes are removing a lot of that stuff. Whatever I am dealing with, isn't a fast killer. In fact I am the bigger killer as the only fish that died were the ones I took out and treated with melafix.

[papwalker]

I've been doing this directly in the tank, not outside. That's how it should be done from what I understand.

Risky.
I would never do that in a live tank, only a 'treatment' tank.
At 1 - 1.5ppm It would destroy the benthic zone and all the biofilm, proteobacteria, flora and biodiversity I've carefully cultivated over time. My tanks would not just cycle they would be devastated.

[Corycory]

Thanks Papwalker. I realize that. I'll keep an eye on this but so far the filter bacteria the least is coping. The level of free chlorine in the tap water according to the local report is 0.3ppm. It should be less devastating than if I put certain medication, as the chlorine will just evaporate. I aerate the tank while doing it too so most of it should evaporate. The tank is going to be stripped down again once I move the fish out when they get healthy again. And thankfully I've got a fishless cycled tank sitting empty at the moment in case I need to react fast. I'll let you know how it turns out. I'll only do it for a week and then I'll do the normal water changes.

[Corycory]

One of the pygmies has disappeared and I haven't seen it in 4-5 days. It was just after I took all the decor out when trying to catch the sick pygmy cory. I have the feeling I siphoned it out or took it out by accident.
Today I found the sick pygmy dead. The the poor thing couldn't make it and I couldn't help it. I am gutted.
Now I am left with the two corys with white bumps on the dorsals and corys with missing barbels. One of these white bump corys actually has all it's barbels and are quite long.
I don't know whether it's a good idea to treat them again.
I was thinking of JBL Furanol 2.

[papwalker]

It's up to you, but if you make a list of your interventions it is quite long. Corys in the wild live a fairly uneventful life.
It can takes weeks for stress effects in fish to subside. Tank changes, water changes, netting and string of medications can be deadlier than the original pathology.

Like I said in my first post, I've found minimal conservative treatment works best.

With many species you must decide whether you want to keep fish or a garden. My tanks don't look pretty because I keep blackwater and Amazonian fish. A plain substrate with dead wood, dead leaves and a few plant species suited to that environment. Corys are a benthic zone species generally used to a rich environment, an organic soup, full of tannins, humic substances, and lots of benthic flora. I never vacuum the substrate or move stuff around or change more than 15% of the water at a time. The only cleaning is done by using the water change to stir up the mulm occasionally. I add standing and creek water full of god knows what to try and get the diversity of flora started. Thus opportunistic pathogens that would attack a weakened fish now also have enemies.

Plain tapwater and flora from around the house will often not suffice to help fish thrive let alone recover.

Hopefully your little fellows will survive.

[Coriequest]

Im very sorry to hear about your sick Corey's. This is interesting information about the benthic zone. I use alder cones, wood and leaves but don't have a spot for the pond water that is chemical free...too much chance of lawn products here...but.something to consider if I come across any. Thx.

[Corycory]

I have several giant almond leaves in the tank, driftwood, amazon swords and anubias, over sand, so it isn't that bad. It's interesting that you say you never vacuum the substrate.
I have at least 50 corys spread around several tanks and although I am not an expert and still learning, I've always managed to keep them happy and I haven't had issues besides this incident. I understand that there are better ways of keeping them too.

On a good note, my sterbai corys in the sick tank were laying eggs today
Is this a good sign I wonder?
This is their first time since I have them. They are only about 1 year old. The lack of barbels didn't seem to stop them doing their T-thing.

[papwalker]

The benthic zone and corydoras.
The substrate of rivers and stream beds varies as they descend from the headwaters. Generally, the closer to the source the coarser the substrate. The faster the current the more finer particles are carried further down to be deposited as the current slows. However, even in the coarser areas some sediment is trapped in slow areas and eddies and and consolidated by biofilms and organic matter. The occasional flash flood will scour some of this away.

When setting up my corydoras tanks I don't use fine substrate. 1 to 2mm being my preference and usually only 1 - 3 inches in depth. I don't wash it. I add a small amount of soils and finer particles and let it settle naturally. Eventually into this works layers of mulm. I run two pumps on aquaria. One (eheim 22xx) for filtration and another Aquael or 'submerged in-tank' to create moderate water flow.
The substrate, over time, will form strata reminiscent of a Winogradsky Column (http://en.wikipedia.org/wiki/Winogradsky_column). Hopefully it will be colonised by a diverse range of flora that reduce organic matter. The flora in the substrate functions like the flora in our digestive tract. The water flow combined with the corys scavenging activities will carry some of the mulm and upper layers into the main filter for disposal. 'Noisy' water changes will stir up some for the same fate and replicate natural disturbances. Onto this I deposit fallen leaves and vegetation.
So the substrate is itself an ecotope. This is why I try and incorporate water and materials from creeks etc. It takes time because of the temperature and water differences between where you find the material and a 'tropical' tank. Time must be allowed for things to acclimate, propagate or perish.
Vacuuming just destroys this system, indeed vacuuming an area that has settled for months or years could be hazardous.

Biodiversity is the name of the game.
Patience and incremental changes.

[papwalker]

Wild

Corydoras cf_arcuatus

Cano de La Libertad, Colombia
Notice the substrate.

cy1.jpg (53.09 KiB) Viewed 5356 times

Lovely muck ere dennis

cy1 (1).jpg (53.25 KiB) Viewed 5356 times

[Corycory]

That's interesting. I think it makes a lot of sense about establishing the right activities in the substrate. My current sand isn't the finest. It has different sizes ranging to 1mm. But for my next tank I was trying to find a slightly larger 1-2mm sand myself in order to provide more oxygenated conditions for the soil beneath, so the right microorganisms develop. It's going to be a low tech but planted tank.

I did another chlorine bath today. I think it's been 7-8 times now. I really see very active corys and the white growths have diminished to almost nothing. I don't know whether to stop now or to keep going another couple of times till all is gone...if it ever disappears. But none are getting worse for sure.

[dw1305]

Hi all,

With many species you must decide whether you want to keep fish or a garden. My tanks don't look pretty because I keep blackwater and Amazonian fish. A plain substrate with dead wood, dead leaves and a few plant species suited to that environment. Corys are a benthic zone species generally used to a rich environment, an organic soup, full of tannins, humic substances, and lots of benthic flora. I never vacuum the substrate or move stuff around or change more than 15% of the water at a time. The only cleaning is done by using the water change to stir up the mulm occasionally. I add standing and creek water full of god knows what to try and get the diversity of flora started. Thus opportunistic pathogens that would attack a weakened fish now also have enemies.

When setting up my corydoras tanks I don't use fine substrate. 1 to 2mm being my preference and usually only 1 - 3 inches in depth. I don't wash it. I add a small amount of soils and finer particles and let it settle naturally. Eventually into this works layers of mulm. I run two pumps on aquaria. One (eheim 22xx) for filtration and another Aquael or 'submerged in-tank' to create moderate water flow.
The substrate, over time, will form strata reminiscent of a Winogradsky Column (http://en.wikipedia.org/wiki/Winogradsky_column). Hopefully it will be colonised by a diverse range of flora that reduce organic matter. The flora in the substrate functions like the flora in our digestive tract. The water flow combined with the corys scavenging activities will carry some of the mulm and upper layers into the main filter for disposal. 'Noisy' water changes will stir up some for the same fate and replicate natural disturbances. Onto this I deposit fallen leaves and vegetation. So the substrate is itself an ecotope. This is why I try and incorporate water and materials from creeks etc. It takes time because of the temperature and water differences between where you find the material and a 'tropical' tank. Time must be allowed for things to acclimate, propagate or perish. Vacuuming just destroys this system, indeed vacuuming an area that has settled for months or years could be hazardous.

Now there is a good post.

I'm a great believer in "Good things come to those who wait", and nice to see another keen follower of the "Skeptical Aquarist" <http://www.skepticalaquarist.com/substrate> as well. With apologies for the cross-post here are a couple of my "mulm and Winogradsky column" posts <http://www.ukaps.org/forum/threads/can- ... ulm.19992/> & <http://www.ukaps.org/forum/threads/biol ... -co.20072/>.

cheers Darrel

[Corycory]

I've done so many water changes on that tank, so there's nothing floating at all. Water is crystal clear during and after.
But I'll take all those suggestions into consideration for my next tank.
It's empty at the moment, just running filters but I intend to set it up with mineralized top soil, capped with sand. There will be plants as well, but not all of it and no carpet plants. Hopefully I'll find larger size sand here as I live in an awkward place and delivery is expensive if ordered online. I've been searching for a month now and all I've found is unsuitable gravel.
I've got plenty of almond leaves so I can add that. I can add up mulm beneath the soil from my other filters as well.
Are there any other things I can get that can be beneficial to corys, or something I need to avoid?
The tank will be 95% or 100% corys. I think I'll move most of them into this tank. It's a 100G tank. Possibly a few forktail rainbows as well but I haven't decided on them.

[papwalker]

Zap over to Conamara in the height of summer. See what's in the creeks and streams.
Look for gravel in the bends.
See what plants grow in the sunny shallows and measure the temperature of the shallows at midday.

If you find plants and flora that will handle 24C you have a great supply of stuff and a great reason to visit 'Gods country'

[Corycory]

He, he. Never thought of that

[Coriequest]

How are the fish now?

[Corycory]

Hi, thanks for asking Coriequest.
It's probably early to tell about the barbels but the white growths have completely disappeared which is the best result so far. I observe them at feeding time to see if anything "new" would appear.
I stopped the "chlorine" baths about the time I posted last time and I did a few normal 50% ones spaced 2 days apart, just in case there is damage to the filters but so far no sign of any troubles in that aspect.

I think I'll space out the water changes a bit far apart, like 3-4 days and then go back to weekly but I may do a few more chlorine baths just in case.
I don't want to jump to conclusions too fast but so far this "treatment" gave the best results.

I had ordered the JBL Furanol plus, but the shop were out of it and after a brief chat with customer care, they sent me JBL Ektopol. This one is not only impossible to put in a tank as it kills all filter bacteria, but is not recommended for corydoras and similar fish so I have no idea why they sold me that instead. It will go to the bin I fear.

[Corycory]

I'd like to revive this thread because whatever these corys had/have is ongoing but it doesn't kill them.

All the corys that survived the initial outbreak more then an year ago are still alive and have been living in another large tank since. They are about 1year and 8 months old now.
Most regrew their barbels beautiful and long but there are a few that never did unfortunately.

The problem is that the white bump on the dorsal fin is an on and off thing and never stopped. At any one time there would be a few affected like 3-4 out of 30+ corys, sometimes down to only one. It doesn't bother them, they feed well and are as active as any cory.
This hasn't spread to my corys in another tank and I use the same python for water changes.
There's no scratching/flashing involved.
If anything, they are a more skittish than their parents in the other tank, hiding from me when if I make sudden movements but do come out buzzing if I place my hand in the tank as if they can smell me. The skittish behaviour is a slight concert why I think that although they act fine generally, they are not as outgoing as my other corys which may point to an issue because something makes them nervous. But then again this could be because where the tank is they isn't much movement and they are not used of people that much where the other group is used of someone being near the tank and they take no notice.

The tank is far from overstocked, it's a 100g tank and I dose KNO3 weekly because of very low nitrates but there were periods of time when I didn't and it makes no difference. It's planted, there are hiding places. The tank gets weekly water changes from 30-50%. The corys have all the bottom to themselves and are not crowded.

The diet is the same as for the other unaffected corys I have in another tank. Staple is NLS community formula and they eat some of the new era plec pellets I give my pleco and some occasional frozen stuff and veggies like blanched peas.

Please look at the pictures in the first page and tell me what you think these corys have that hasn't killed anyone of them in a year but won't go away?
I've read numerous threads, some say the diet but then my other corys should be affected too as they get exactly the same diet. However, I can still address that, maybe they eat too much because it's not a very competitive tank.

If it is parasitic, it doesn't kill them or even cause secondary problems.
If it is bacterial or fungal, again it hasn't killed them either and they act as if there's no problem. It has not spread to any other fish which are livebearers and a pleco. However, it is almost always on the "bronze" looking aeneus and not the albinos although there was a period of time when the aeneus were affected but they cleared up and never got it again. This could also be because they actually segregate by colour in the tank. It's a 5f tank, one side a group of albinos, at the other the group of "bronze" ones that are on the initial pictures. They mix up from time to time though and eat together obviously.
The sterbai corys with them have never been affected by it and they always stay with the group of "bronze" corys.


The white bump is always at the base of the dorsal at the back side as in the pictures, does not eat into the dorsal fin at all and doesn't damage it or spread anywhere on the fish. At fist it looks like a white tear drop along the last ray of the dorsal fin. Then it seems it kind of "bursts" and looks a bit stringy but then without disappearing completely it can "refill" and look like a bump again. But it can completely disappear and appear on another cory. It doesn't affect the barbels of the "infected" fish or their appetite or cause any other issues.

I am sorry for the long post. I really hope someone has any idea what that is. It's full of pictures on internet with corys having exactly the same thing but no resolution or people haven't updated their threads with the solution if any.

Thanks for reading.