Why Am I Losing Cories? Help!

[Harlequins]

I bought some cory julii last week,the first 3 i got,one died the next day,has i explained at the time the lfs replaced it.

So after having 6 cories on friday last week,every few days a cory has been dying! lost another one today,so from this latest batch i've 3 young cories.
I measured this more its only 2.5cms,which is less than half their size.
All the dead showed the same thing,had been eating,swimming,do everything,then suddenly resting on the floor not moving,then within 12 hrs had died!!
There was no marks,spots,lesions,no red gills etc,all fish looked ok apart from obviously being dead!!
It's colour may have appeared a bit darker with the tank light on!
I treated the tank last night with interpet 9 to rule out internal parasites

The original 2 i had seem larger,there's still a small one left,

Water stats are fine,ammonia 0,nitrite 0,nitrate 20(tap 10),ph 8,temp 26.

Am i doing something wrong?

Should i phoned the lfs and ask if they've had a problem? although they said not when i questioned the first one dying!

I'm so i've been losing them

All the other fish are fine!

 

[OldMan47]

Your water is too warm for a Corydoras trilineatus, false julii, and the pH indicates that you probably have rather hard water. Almost any cory will do much better in soft water. Depending on what else you have in the tank, the temperature needs to come down within the range for the cory which is from 16C to 25C. The listed water conditions for that cory is a pH of 5.8 to 7.2.
In short, your water conditions are not fine for that fish.
If you actually got one of the rather uncommon julii cories, their water requirements are much like those for the trilineatus. The reason that I doubt the true julii is quite simple, you would be paying quite a bit for each one and would probably be a cory specialist if you were willing to pay that much for them. The trilineatus are almost always marked as julii and are sold at reasonable prices for a cory.

 

[Zachary1941]

I bought some cory julii last week,the first 3 i got,one died the next day,has i explained at the time the lfs replaced it.

So after having 6 cories on friday last week,every few days a cory has been dying! lost another one today,so from this latest batch i've 3 young cories.
I measured this more its only 2.5cms,which is less than half their size.
All the dead showed the same thing,had been eating,swimming,do everything,then suddenly resting on the floor not moving,then within 12 hrs had died!!
There was no marks,spots,lesions,no red gills etc,all fish looked ok apart from obviously being dead!!
It's colour may have appeared a bit darker with the tank light on!
I treated the tank last night with interpet 9 to rule out internal parasites

The original 2 i had seem larger,there's still a small one left,

Water stats are fine,ammonia 0,nitrite 0,nitrate 20(tap 10),ph 8,temp 26.

Am i doing something wrong?

Should i phoned the lfs and ask if they've had a problem? although they said not when i questioned the first one dying!

I'm so i've been losing them

All the other fish are fine!

Hi Harlequin,
Remember your last thread when you lost a Cory, seems its repeating itself again...Your water stats are identical to mine and my 3 corys have been fine now for 7 weeks...appears as if the problem is at the fish shop end from what you have said........One thought .. Are the Corys getting food.. might seem a silly question .. but when i feed my fish the Zebra Danios grab everything almost .. so i now feed the corys their food and the the other fish at the other end of the tank...Also is it possible they are being attacked.and stressed out.Apart from that really unable to help you, sure someone with experience will be along shortly Chin up mate Regards Zac


Right.. should have been more careful reading you Harlequin.. Mine are Albino"s.. must be a slight difference in their water requirements Sorry Regards Zac

 

[crazychris]

Your water is too warm for a Corydoras trilineatus, false julii, and the pH indicates that you probably have rather hard water. Almost any cory will do much better in soft water. Depending on what else you have in the tank, the temperature needs to come down within the range for the cory which is from 16C to 25C. The listed water conditions for that cory is a pH of 5.8 to 7.2.
In short, your water conditions are not fine for that fish.
If you actually got one of the rather uncommon julii cories, their water requirements are much like those for the trilineatus. The reason that I doubt the true julii is quite simple, you would be paying quite a bit for each one and would probably be a cory specialist if you were willing to pay that much for them. The trilineatus are almost always marked as julii and are sold at reasonable prices for a cory.

No disrespect to OldMan47 but I don't think a temp. of 79 deg would be the cause of death of those fish or the PH. I'd say it was a bad batch from the LFS or bad acclimatisation. I'd agree they're probably Trileanatus though, false Julii. I've had a true Julii for 5 years now and it's been fine, hardy as anything.

OP try another LFS next and try one of the three most common cories next, bronze, albino or leopard.

 

[Harlequins]

The temp is now 25.6,the room is so warm i find it hard to keep the temp down but it tends to drop at night.

I acclimatised them correctly i thought,they were in the bag for nearly an hour,from 25 mins onwards i added small amounts of tank water every 10 mins,then carefully put them in using the net.

Seems strange they all seem to be acting the same way before they died.

The lfs was maidenhead aquatics and are pretty clued up for a lfs and seemed pretty certain they were julii's cost me £5 each.

I think there fish are from singapore,would they be caught in the wild or tank bred?,

Here's a pic what do you reckon,they appear to have spots on their heads has opposed to stripes like the false julii?

 

[OldMan47]

The fish in your picture is a trilineatus. Where the marbled look on the fish's forehead is would just be separate dots on a true julii. If you had true julii, they are seldom if ever tank bred. That is one reason that they are quite dear. The trilineatus are very popular so they are a bit more expensive than some of the other cories but not like a true julii. They are tank bred, or maybe farm bred in Singapore, so they can be obtained at reasonable prices.

 

[RobynR]

Just thought I'd say that I have 5 corys (trilineatus, actually) in my tank -- I added them last Saturday. They're the only inhabitants so far. I realized on Wednesday that I had the temperature in their tank at 86F instead of 76F like I thought. I've read the highest comfortable temperature for them is 78. I've been gradually dropping the temperature in their tank to 78F. I felt absolutely terrible about it, but so far I haven't had any casualties. One did seem a little stressed in the first 15 minutes or so after I put them in the tank, but since then they've all been busy and active. They've colored up a fair bit since the temperature has been dropping, so the heat was definitely not ideal for them, but it didn't kill them. It might help that my water is soft and my pH is just a smidge above 7 -- so the temperature would be the only real stressor, at least. Hope you're able to solve your problem!