# Cory pandas keep dying



## pseudodiego (8 Feb 2022)

Hi everyone.

For some reason, I'm having trouble keeping new panda corys alive.

I have a 80 gallon tank going with 50 tetra cardinal, 6 otocinclus, 5 vampire shrimps, and two honey gourami(Planning to add three more).

Three times I tried adding corydoras panda and the three times they get sick and ends dying.

The parameters are as follow:
7 PH
5 GH
2 KH
0 ammonia
0 nitrates
Under 10 nitrites.

The temp is 24 C, and about filtration, I have a JBL 1500, a aquaclear 70 and a 2200 liters/h sump. So no problem there either.

The rest of the fish are perfect, not a single one died. Isn't a new tank either as the tank have been going for over one year with different species. It's just the panda cories.

About plants, I have anubias, java fern and cryptocorynes submersed, and above water I have some big pothos and peace lilies.

I have buy three times from three different reputable stores, so it doesn't seem to be bad stock either. I buy them online, and I have them at home in under 16 hours. 

I have read about this: *Corydora Self Poisoning*. 
But wouldn't that be a widespread issue with all cories then?

Any idea where the problem might be? Thanks.


----------



## Hufsa (8 Feb 2022)

Do you mean 0 nitrite and 10 nitrate? 

How often do you change your water? Do you have access to a TDS (conductivity) meter?


----------



## shangman (8 Feb 2022)

I think it would be useful to see a picture of the tank, and can you describe also how they died/how long it took and symptoms?

It could be something about the substrate, since the cories would interact with that and none of the other fish would. Do you have sand, gravel, soil? What types?


----------



## pseudodiego (8 Feb 2022)

Hufsa said:


> Do you mean 0 nitrite and 10 nitrate?
> 
> How often do you change your water? Do you have access to a TDS (conductivity) meter?


Yeah.

I do 50% weekly, and I have no access to a TDS meter.


----------



## X3NiTH (8 Feb 2022)

Are the Peace Lily roots in the aquarium and accessible by the Pandas if they are then the Pandas could be grazing around them and there is a possibility that any increased concentration of oxalate released from tissues may be affecting them.


----------



## pat1cp (8 Feb 2022)

How are you feeding them?


----------



## pseudodiego (8 Feb 2022)

shangman said:


> I think it would be useful to see a picture of the tank, and can you describe also how they died/how long it took and symptoms?
> 
> It could be something about the substrate, since the cories would interact with that and none of the other fish would. Do you have sand, gravel, soil? What types?







The substrate is sand, they never seems pretty active as soon as I put them in, and after a few days they show erratic behavior, falling on their sides and it get worse until they die. The substrate is pretty clean.


----------



## pseudodiego (8 Feb 2022)

pat1cp said:


> How are you feeding them?





That, and some frozen artemia from time to time and some spirulina tabs. Besides the tetra food that falls to the ground.


----------



## pseudodiego (8 Feb 2022)

X3NiTH said:


> Are the Peace Lily roots in the aquarium and accessible by the Pandas if they are then the Pandas could be grazing around them and there is a possibility that any increased concentration of oxalate released from tissues may be affecting them.


Nope, they are in a small side aquarium with a pea puffer, connected to the main aquarium. The corys can't interact directly with the roots.


----------



## Jaseon (8 Feb 2022)

I was going to say something about the substrate. It dont look very welcoming. The island looks very nice.


----------



## AlecF (8 Feb 2022)

Yes, that sand worries me a bit. They put sand through their gills. Do they have flukes? When I had deaths it was usually that. Mine were posted as well.


----------



## Konsa (8 Feb 2022)

pseudodiego said:


> Nope, they are in a small side aquarium with a pea puffer, connected to the main aquarium. The corys can't interact directly with the roots.


Hi
you can get some MTS snails if they make it(as they live in substrate mainly) that should rule out substrate issues 
Regards Konstantin


----------



## pseudodiego (8 Feb 2022)

AlecF said:


> Yes, that sand worries me a bit. They put sand through their gills. Do they have flukes? When I had deaths it was usually that. Mine were posted as well.


It is this one:
Sand


----------



## Hufsa (8 Feb 2022)

pseudodiego said:


> .. they never seems pretty active as soon as I put them in, and after a few days they show erratic behavior, falling on their sides and it get worse until they die. ..


Just to clarify, they seem active when you put them in or they dont?
That they are dying within a few days suggests a larger issue to me. Do you gradually acclimate them to your water when you get them, or do you put them right from the bag to your tank?

That you do regular waterchanges is good, this excludes my first idea which was old tank syndrome.


----------



## pseudodiego (8 Feb 2022)

Konsa said:


> Hi
> you can get some MTS snails if they make it(as they live in substrate mainly) that should rule out substrate issues
> Regards Konstantin


Might do so, but I think I'm done with cories in this aquarium.


Hufsa said:


> Just to clarify, they seem active when you put them in or they dont?
> That they are dying within a few days suggests a larger issue to me. Do you gradually acclimate them to your water when you get them, or do you put them right from the bag to your tank?
> 
> That you do regular waterchanges is good, this excludes my first idea which was old tank syndrome.


I acclimated drip by drip over three hours. Same method that I used for the otocinclus and they are perfectly fine.

They were lethargic when I put them in. I have never observed in any of them the normal behavior of a corydora, they just move for a bit searching for food, and them stays still for a long time.


----------



## PARAGUAY (8 Feb 2022)

Could be the substrate. A quarantine tank first would be ideal as if they are ok in that it tells you something. Looks like water quality is ok other fish are ok. Bought and delivered could be incorrect transit fish suffering stress on arrival. A sort of exhaustion not apparant to us. Otto's tend to rest on leaves above the substrate. Adding botanical leaves may help if the substrate can be ruled out


----------



## AlecF (9 Feb 2022)

I'm still a newbie and can't give accurate advice, but given that cories sift sand through their gills I think any gravel can be an issue. I wonder if you could add an area of sand? But the substrate may not be the issue. I had a delivery where quite a few died in the issue was flukes. Do they have any red markings? It could be worth trying anti-fluke meds. A lot of people quarantine them with some anti-fluke meds. Small cories do seem sensitive in the first month. Usually if they get through that they are fine. Adding leaves is a great idea, especially oak and almond. Actually when I look at the tank I think replacing all the substrate may not be that difficult. You've made a beautiful tank. My habrosus go through periods of being still. They did it more when other fish were in there. I think what Paraguay says is true, that if they are wild caught they may arrive and still be in shock and underfed.


----------



## pseudodiego (9 Feb 2022)

AlecF said:


> I'm still a newbie and can't give accurate advice, but given that cories sift sand through their gills I think any gravel can be an issue. I wonder if you could add an area of sand? But the substrate may not be the issue. I had a delivery where quite a few died in the issue was flukes. Do they have any red markings? It could be worth trying anti-fluke meds. A lot of people quarantine them with some anti-fluke meds. Small cories do seem sensitive in the first month. Usually if they get through that they are fine. Adding leaves is a great idea, especially oak and almond. Actually when I look at the tank I think replacing all the substrate may not be that difficult. You've made a beautiful tank. My habrosus go through periods of being still. They did it more when other fish were in there. I think what Paraguay says is true, that if they are wild caught they may arrive and still be in shock and underfed.



Thanks. I'll see about the fluke

About the substrate, I think isn't gravel. This is the product from up close:


----------



## AlecF (9 Feb 2022)

Maybe, but I wonder if it is gritty and has sharp pieces? Perhaps it's fine for cories, but I am always aware that as their natural feeding technique is to expel the sand through their gills they can suffer if the sand is sharp. Others will know better. Anyway, it doesn't sound like the cause with yours, which seem more affected by travel and malaise. I wouldn't be put off, but I might switch to a different type pf Cory. I have found false Julii the strongest of the ones I tried. I do also think a quantity of leaf litter, which they like to hide in. I think even neons can possibly be a worry to cories in an exposed scape. I noticed my habrosus change behaviour and explore much more after I removed some juvenile pencilfish. The pencils ignored them, but I think they didn't like to see any fish swimming above them. Again, that's not really the issue your concerned with.


----------



## mort (9 Feb 2022)

Hi, I've just skimmed the thread but I see they were sent overnight and then they had a long acclimation. I don't have time at the minute to go into detail but if the others think I'm right then perhaps one would clarify, but this might be the problem. Overnight shipping and then a lengthy acclimation with the bag open to the air  might be the issue. The fish pollute the water but it isn't a problem until you open the bag.


----------



## pseudodiego (9 Feb 2022)

mort said:


> Hi, I've just skimmed the thread but I see they were sent overnight and then they had a long acclimation. I don't have time at the minute to go into detail but if the others think I'm right then perhaps one would clarify, but this might be the problem. Overnight shipping and then a lengthy acclimation with the bag open to the air  might be the issue. The fish pollute the water but it isn't a problem until you open the bag.


I really think that it's a problem with the shipping of that concrete species and not a thing with my sand. So you may be into something.

The last shipment was three days ago. Two have died, another two looks sick, and the other four are more or less ok: not super active, but searching for food in the sand as a group, as cories do. I don't think any problem with the sand would have killed those two so quickly.

They must be really sick when I introduce them into the tank, or some chemical of the tank is affecting them that doesn't affect the other fish.

I'll see how the ones that are ok fare, if I observe that they are getting sicker, I'll scoop them out and put them in a tank without sand.


----------



## Doogle (9 Feb 2022)

I wonder if that stuff is black diamond blasting sand? If so that stuff seems to have mixed opinions online if it is toxic or not, I lost 2 of my three lined corys which I suspect was due to my black gravel as the remaining 5 didnt look great either, switched to playsand and they bounced back, all in good health and love sifting/burying their faces playsand as it has smooth granules.

Not sure if it was due to the gravel or maybe waste getting stuck between the gravel and rotting into nastyness.

None of my mid water fish died during this time but I did lose a few shrimp (now they are everywhere).

Not sure if this anecdote helps but it hopefully shows substrate alone can affect bottom dwellers while midwater fish do fine.

*edit: sorry was Tahitian Moon Sand that has mixed opinions regarding toxic heavy metals, forgot why I didnt go for blasting sand, think blasting sand has sharp granules but isnt toxic.


----------



## pseudodiego (9 Feb 2022)

Doogle said:


> I wonder if that stuff is black diamond blasting sand? If so that stuff seems to have mixed opinions online if it is toxic or not, I lost 2 of my three lined corys which I suspect was due to my gravel as the remaining 5 didnt look great either, switched to playsand and they bounced back, all in good health and love sifting/burying their faces playsand as it has smooth granules.
> 
> Not sure if it was due to the gravel or maybe waste getting stuck between the gravel and rotting into nastyness.
> 
> ...



If your shrimp were affected, it isn't the same I think. I have 5 Vampire shrimp that live constantly in the ground, and I have keep some neocaridinas and amano shrimps  without problem too.

Here is a review from another user on the sand:

"i was a bit concerned buying this as there were no reviews on here yet, but decided to give it a go, as it was such a good price compared to others id seen, i was worried about cloudiness ect, but this sand is great, i rinsed it thoroughly {packaging said to rinse until water runs clear, it was clear straight away, though i did continue rinsing just incase) i then soaked it in water conditioner before adding it to the tank, my tank was already full of water and this fell beautifully straight to the bottom of the tank, no clouding or anything it just settled beautifully, there were a few air pockets which made a few bits of sand form little balls which floated about, but you just pop them and they fall to the bottom too, it has a lovely deep black colour, although when i put the bright light on in the tank it makes it look brown, but i don't often use this light, so that's not a problem, it also went a lot further than i thought it would and i have plenty left for my large tank when i get it, i will be aquascaping the large tank so although its massive i will only use it at the front, as the back will be soil and plants. *my corydoras seem absolutely love it, its nice and soft for them to big around in*  i'm so happy i bought this and i highly recommend it  also was very quick delivery and great price"


----------



## Conort2 (9 Feb 2022)

pseudodiego said:


> The last shipment was three days ago. Two have died, another two looks sick, and the other four are more or less ok: not super active, but searching for food in the sand as a group, as cories do. I don't think any problem with the sand would have killed those two so quickly.


Can you provide pictures of the ones that are alive please?


----------



## pseudodiego (9 Feb 2022)

Conort2 said:


> Can you provide pictures of the ones that are alive please?


Yeah, I'll upload them when I got home.


----------



## John q (9 Feb 2022)

mort said:


> Overnight shipping and then a lengthy acclimation with the bag open to the air might be the issue.


I'd be tempted to go with this as the probable cause.

I know some people have success with buying fish online but personally I'm not a fan. If these fish were in a bag for 16hrs then waste levels will increase. The ph level will probably be low until you open the bag due to co2 build up, but will then rise once opend, any unharmfull ammonium will be converted to ammonia and likely have a detrimental effect on the fish.


----------



## pseudodiego (9 Feb 2022)

John q said:


> I'd be tempted to go with this as the probable cause.
> 
> I know some people have success with buying fish online but personally I'm not a fan. If these fish were in a bag for 16hrs then waste levels will increase. The ph level will probably be low until you open the bag due to co2 build up, but will then rise once opend, any unharmfull ammonium will be converted to ammonia and likely have a detrimental effect on the fish.


Thing is, I buy all my fish like this, and it's very strange occurrence for those fish to die. tetras,  gouramis, bettas, shrimps of all types, danios, loricariidae, etc. It only happened to me with the panda cories, and in three different ocassions from different vendors.


----------



## Nont (9 Feb 2022)

I’m sorry for your loss.

From what I read, it seems like Panda cories are prone to everything.
Take a look at all these threads:
Panda Cories keep dying | Corydoras Forum | 168802





						Panda Cory’s Dying!
					

I have lost 3 panda Cory in 5 days.  Two today.  Nothing visibly wrong.  Parameters are 0, 0, 20.  Just did pwc and nitrates now 5ppm.   PH is 7.8.  Can’t find test kit but GH 10 and KH 6 or 107 last test. Temp 76F. Nothing added to tank except dechlorinator.  Fish treated with General Cure over...



					www.fishforums.net
				








						HELP! My Cory Pandas are dying one by one.
					

Hi everyone,  Last week I bought 4 corydoras panda to my 20H gallon along with 8 rummynose tetras and 1 honey gourami in addition to 6 cardinals that I previously had. The cardinals have been with me for at least a year. All the fish are doing well. However, one of my corys died yesterday and...




					www.aquariacentral.com
				








						Can't seem to keep panda corys!
					

Help!  I've had a 25 gal for about 3 months and recently bought some panda corys  (6 about 3wks ago)  They were VERY SMALL and all  but one has died. From what I'ver read corys like a lower Ph (mine is bet 6.8 -7.0).  Ammonia level is at 0 and my pet store who tested nitrate level said all was...




					www.aquariacentral.com


----------



## pseudodiego (9 Feb 2022)

Another one died. 3 of 8, and another is having trouble staying in normal position, I think it'll die soon too.

Just caught this on video from one of the "ok" ones. It did it a couple on times in 15 minutes, but the other four doesn't seems to be doing it. Not sure if it might be related or if is normal cory behavior.


----------



## Conort2 (9 Feb 2022)

pseudodiego said:


> Another one died. 3 of 8, and another is having trouble staying in normal position, I think it'll die soon too.
> 
> Just caught this on video from one of the "ok" ones. It did it a couple on times in 15 minutes, but the other four doesn't seems to be doing it. Not sure if it might be related or if is normal cory behavior.


Maybe gill flukes? It’s breathing quite rapidly and the flicking is something I’d associate with it. 

Corydoras panda are mass produced fish alongside Aeneus and Paleatus. These often seem to arrive in questionable condition. What exactly is your substrate? I can’t view the link as it’s Amazon USA.


----------



## pseudodiego (9 Feb 2022)

Conort2 said:


> Maybe gill flukes? It’s breathing quite rapidly and the flicking is something I’d associate with it.
> 
> Corydoras panda are mass produced fish alongside Aeneus and Paleatus. These often seem to arrive in questionable condition. What exactly is your substrate? I can’t view the link as it’s Amazon USA.








						AMTRA FINE BLACK SAND 0,3-0,9mm - Amtra
					

AMTRA FINE BLACK SAND 0,3-0,9mm - black sand of fine size specially selected to recreate the bottom of the aquariums




					amtra.net


----------



## Conort2 (9 Feb 2022)

pseudodiego said:


> AMTRA FINE BLACK SAND 0,3-0,9mm - Amtra
> 
> 
> AMTRA FINE BLACK SAND 0,3-0,9mm - black sand of fine size specially selected to recreate the bottom of the aquariums
> ...


It looks rather sharp, however I wouldn’t think this would kill a corydoras.


----------



## PremierFantasy88 (9 Feb 2022)

pseudodiego said:


> three different ocassions from different vendors


Realistically even though you have got these pandas from 3 different stores/sellers there is still a chance that they are coming from the same place.... a lot of stores in the UK get their livestock from the same suppliers (even if you are not based in the UK I wouldn't imagine this practice varies much in other countries but could be wrong)

My experiences with pandas is that for some reason they are more susceptible to just dying for no apparent reason. As another poster has mentioned maybe because they are mass produced in a lot of cases


----------



## mort (9 Feb 2022)

Were the cories active in the bag before you started acclimation?  Just trying to rule out acclimation stress. We would get cory shipments with far larger numbers and they often looked ropey in the bag so we got them out straight away. It depends on how they were packaged but most wholesalers just temperperature acclimate the fish by floating the bag and then cut the top off and take the fish out straight into new water.  We did the same with our imports and never knowingly lost a fish this way.

The problem is its hard to rule anything out at the moment. It could be rough handling in the post, an acclimation issue, poor stock or disease.  Can you describe any symptoms in as much detail as possible. I can't see the vid and trust Conort2 with his fish knowledge but ammonia poisoning will also show as heavy breathing and similar symptoms to flukes, so it's hard to rule anything out at the moment.


----------



## pseudodiego (9 Feb 2022)

mort said:


> Were the cories active in the bag before you started acclimation?  Just trying to rule out acclimation stress. We would get cory shipments with far larger numbers and they often looked ropey in the bag so we got them out straight away. It depends on how they were packaged but most wholesalers just temperperature acclimate the fish by floating the bag and then cut the top off and take the fish out straight into new water.  We did the same with our imports and never knowingly lost a fish this way.
> 
> The problem is its hard to rule anything out at the moment. It could be rough handling in the post, an acclimation issue, poor stock or disease.  Can you describe any symptoms in as much detail as possible. I can't see the vid and trust Conort2 with his fish knowledge but ammonia poisoning will also show as heavy breathing and similar symptoms to flukes, so it's hard to rule anything out at the moment.


Not super active, but no floating problem or anything like that.

They seems to breath fast, they act very passive and after a few days they swim weird, getting sideways. A few days later, they die. The video shows one of them scratching against the ground, but that doesn't seems a widespread issue.


----------



## mort (10 Feb 2022)

Still very hard to narrow it down. Ammonia poisoning can cause fast breathing and lethargy before the fish deteriorate further and pass. I don't know if flicking is a symptom, or at least not one I've heard (perhaps @Conort2   or @MirandaB  have come across it). If you look closely at the fishes gills you might see signs that pinpoint this and if the bodies develop red areas it could also suggest this might be the problem.
Gill flukes as suggested earlier is another disease that present in this way but often symptoms are common among various disease so it's very tricky.


----------



## mort (10 Feb 2022)

mort said:


> Hi, I've just skimmed the thread but I see they were sent overnight and then they had a long acclimation. I don't have time at the minute to go into detail but if the others think I'm right then perhaps one would clarify, but this might be the problem. Overnight shipping and then a lengthy acclimation with the bag open to the air  might be the issue. The fish pollute the water but it isn't a problem until you open the bag.



I didn't see this thread before but it has the explanation of what I was thinking 







						To drop acclimate or not?
					

I’m planning on buying some fish this Sunday coming, 2 comet goldfish to go into my 500L tank with my lonely 23 year old goldfish and 2 honey gourami to go into my 100L tropical community tank.   Before now, I’ve always used the “plop and drop” technique that many fish people on YouTube advocate...



					www.ukaps.org


----------



## arcturus (10 Feb 2022)

@pseudodiego : have you reported this issue to the fish stores from where you are buying the pandas? At the very least I would ask them about the water parameters they keep these corydoras in (pH, dKH, dGH, overall TDS). If these parameters are similar to the ones in your tank, then I would just plop them in the tank as soon as they arrive to avoid potential ammonia poisoning (and keep the bag sealed until you put them in the tank). You could ask the vendors to ship the corydoras in several bags, ideally just one fish per bag. This should not be an issue because the styrofoam transport boxes are usually big enough to hold several bags. I am assuming these fish were shipped together in a single bag, since this is the usual (and bad) practice with small fish. But this situation is very hard to diagnose and can be something in your tank.


----------



## MirandaB (10 Feb 2022)

If they were shipped together in the bag I'd say that's the most likely cause of the issues...problems due to ammonia building up in the bag and then subsequent acclimating are usually pretty instant.
I've only had that happen once when some fish were sent to me with too many fish in bags that were way too small,within 2 minutes of opening the bags they went belly up due to ph drop....never had a problem acclimating before or since.


----------



## mort (10 Feb 2022)

I don't know if the problem is becoming more prevalent but I've seen quite a few people suffer with possible shipping issues and I wonder if it's partly because postal costs have risen, so some suppliers are minimising the amount of weight by reducing water. Certainly here sellers that use royal mail, often keep weight down to the cost of the fish. 

Were these fish sent in a large/adequate poly box or was it a bit of a squeeze? 

Sometimes sellers also ship fish out that have only just recently arrived and multiple shipping stresses can really do some damage.


----------



## pseudodiego (10 Feb 2022)

mort said:


> I don't know if the problem is becoming more prevalent but I've seen quite a few people suffer with possible shipping issues and I wonder if it's partly because postal costs have risen, so some suppliers are minimising the amount of weight by reducing water. Certainly here sellers that use royal mail, often keep weight down to the cost of the fish.
> 
> Were these fish sent in a large/adequate poly box or was it a bit of a squeeze?
> 
> Sometimes sellers also ship fish out that have only just recently arrived and multiple shipping stresses can really do some damage.


They were all sent in big bag, same as the other fish. Maybe they are more prone to have problems when shipped like that. If I buy any more cory, it will be in person. 

The five remaining were okay today, even the one that were not okay yesterday.
Pretty active and eating normally as a group, no signs of scratching or bad swimming. I hope they don't relapse.


----------



## mort (10 Feb 2022)

MirandaB said:


> If they were shipped together in the bag I'd say that's the most likely cause of the issues...problems due to ammonia building up in the bag and then subsequent acclimating are usually pretty instant.
> I've only had that happen once when some fish were sent to me with too many fish in bags that were way too small,within 2 minutes of opening the bags they went belly up due to ph drop....never had a problem acclimating before or since.



Hi miranda, so are you thinking it was due to them being shipped together rather than due to ammonia (because the reaction was to slow). I've read your reply a couple of times and think you are suggesting it's not ammonia but it reads both for/against in my head.


----------



## MirandaB (10 Feb 2022)

mort said:


> Hi miranda, so are you thinking it was due to them being shipped together rather than due to ammonia (because the reaction was to slow). I've read your reply a couple of times and think you are suggesting it's not ammonia but it reads both for/against in my head.


Hi Mort,sorry I should have made that clearer.
Yes I think it's more likely down to them all being shipped in the same bag which is not a good idea at the best of times but even less so with Cory.


----------



## Conort2 (10 Feb 2022)

pseudodiego said:


> They were all sent in big bag, same as the other fish. Maybe they are more prone to have problems when shipped like that. If I buy any more cory, it will be in person.


I think that may be the issue, especially as corydoras are known to release a toxin when stressed. They should ideally be sent individually. I had 18 small tetras sent recently and each was individually bagged so there should be no excuse for something risky like a corydoras. You also have the issue that if one dies in the bag they all die.


----------



## X3NiTH (10 Feb 2022)

MirandaB said:


> within 2 minutes of opening the bags they went belly up due to ph drop



From what I have learned Fish travelling for a long time in a sealed bag will experience the pH drop, this generally isn’t the problem, the problem is that the moment you open that bag the oxygen depleted water will suddenly gain access to a huge influx of oxygen and because of the guaranteed presence of Ammonium from the Fish (in Ammonium form because the below neutral pH lowered from CO2 via respiration) it will all be converted to 10x more toxic Ammonia as the pH climbs above neutral as the gases in the water equilibriate with the atmosphere. The longer the time in the open bag the greater the risk of this happening.

There’s two options here, in both cases Temperature acclimate with the bag remaining sealed and floating in the aquarium (or elsewhere but to the same temp).  If needing to Drip acclimate then open the bag (before or after reaching temperature) and dose the correct amount of Ammonia detoxifier for the volume of water in the bag (measured by displacement, Archimedes principle), then drip acclimate. The other option is once at temperature hold the bag by the neck to keep the original atmosphere, unseal the bag and upend the whole contents into a net suspended over a bucket and then quickly place the fish into the receiving Aquarium.

The first option I think is best performed if the fish are going into dissimilar water parameters from where they were originally kept, the second option is best if you know the water parameters are similar or if forced by an emergency in the bag, I would class a large amount of Ammonium in the bag and no way to immediately detoxify as an emergency.


----------



## pseudodiego (10 Feb 2022)

Conort2 said:


> I think that may be the issue, especially as corydoras are known to release a toxin when stressed. They should ideally be sent individually. I had 18 small tetras sent recently and each was individually bagged so there should be no excuse for something risky like a corydoras. You also have the issue that if one dies in the bag they all die.


Been buying fish for a long time here at spain at very different online stores and not once they have send the fish separated. Sounds like a good practice.


----------



## mort (11 Feb 2022)

MirandaB said:


> Hi Mort,sorry I should have made that clearer.
> Yes I think it's more likely down to them all being shipped in the same bag which is not a good idea at the best of times but even less so with Cory.



Can I ask what you think the mechanism is in this case? Poor water quality or the famed release of toxins cories are capable of? 

With regards to toxins the only time I've seen it has been with big cories in a large number and the water was very frothy on top and quite milky/yellow in colour. My wholesaler friend said it's generally noticeable when this happens but that is with higher stocking density (and im remembering from years ago). I didn't think pandas were supposed to be that problematic, it was more an issue with bigger bodied species like sterbai (the ones I had problems with), trillineatus, Julii etc. There is no doubting pandas can be quite sensitive so poor water quality is certainly a sensible conclusion.


----------



## MirandaB (11 Feb 2022)

X3NiTH said:


> From what I have learned Fish travelling for





mort said:


> Can I ask what you think the mechanism is in this case? Poor water quality or the famed release of toxins cories are capable of?
> 
> With regards to toxins the only time I've seen it has been with big cories in a large number and the water was very frothy on top and quite milky/yellow in colour. My wholesaler friend said it's generally noticeable when this happens but that is with higher stocking density (and im remembering from years ago). I didn't think pandas were supposed to be that problematic, it was more an issue with bigger bodied species like sterbai (the ones I had problems with), trillineatus, Julii etc. There is no doubting pandas can be quite sensitive so poor water quality is certainly a sensible conclusion.


To be honest it could be either or a combination of both but it would have been interesting to see just how bad the bag water was for ammonia etc.
Spoke to my lfs and they say they've had toxin issues a couple of times but it was sterbai in both cases.
@pseudodiego do they ship overnight by courier over there?


----------



## X3NiTH (12 Feb 2022)

On occasion I have seen large volume Cory shipments arrive like a bag of milk, it’s not pretty and not always a total loss. The more successful shipments usually come with a handful of Zeolite and Activated Carbon in the bottom of the bag. Pandas are Venemous so I believe the chances for self poisoning through excretion or harm during transport are higher.


----------



## pseudodiego (12 Feb 2022)

MirandaB said:


> To be honest it could be either or a combination of both but it would have been interesting to see just how bad the bag water was for ammonia etc.
> Spoke to my lfs and they say they've had toxin issues a couple of times but it was sterbai in both cases.
> @pseudodiego do they ship overnight by courier over there?


Yeah. It usually ships around 20:00 of the previous day and arrives 11:00/12:00 of the next day.


----------



## pseudodiego (19 Feb 2022)

Happy to say that the five corys are still alive and acting normally now.


----------



## NatalieHurrell (7 Mar 2022)

mort said:


> Hi, I've just skimmed the thread but I see they were sent overnight and then they had a long acclimation. I don't have time at the minute to go into detail but if the others think I'm right then perhaps one would clarify, but this might be the problem. Overnight shipping and then a lengthy acclimation with the bag open to the air  might be the issue. The fish pollute the water but it isn't a problem until you open the bag.


I thought this too, plus if the bag isn't floated in the aquarium to keep it warm the temperature will drop further still.


----------



## PARAGUAY (8 Mar 2022)

I have seen this in a  shop with a delivery of fish The bags were  placed in tanks unopened. Great news the Corys doing well @pseudodiego


----------

