Sick Cory...desperate keeper!

Hey there,
I have three corys who have been living happily with half a dozen diamond tetras for several months with no problems. I'm super-vigilant about water quality and change it and/or test it every day - ammonia, nitrate and nitrite levels are all fine. But just over the last couple of days two of the corys have been acting kind of lethargic until this morning, one of them stopped moving at all - when I netted him to move him into a qaurantine tank he made only a feeble attempt to get away from the net. The other cory is a bit better (he rushes away when I look through the tank glass at him) and the third cory couldn't be better! The tetras are all absolutely fine as well. And I'm very confused! The sick corys were occassionally trying to bolt to the surface, would rest in the upper leaves of the aquarium plants or would just lay on the bottom of the tank, barely breathing.
Does anyone have any idea what could be wrong with them?!!!

Thanks so much in advance.

 

I wonder...are you running an airstone or other means of adding extra oxygen to the water?? It nearly sounds like a build up of carbon dioxide is starting somehow in your tank. The higher the water temperature the less able it is to hold oxygen. That is why a lot of aquarium owners have at least one or perhaps more than one airstone or wand in a tank. If you are running airstones or wands and have still had this problem, you have me stumped.

Rose

 

Thanks Rose, I'll definitely try that. The sickest cory died just before but I'll get an airstone asap and hope the others pull through.

 

I am so sorry about the Cory dying.  I wish I could have helped sooner, but there are so many things that can upset the balance in a tank.  I am really hoping this will help you.  If you notice any other symptoms or if you just want to chat please don't hesitate to post to the forum.  Someone is usually always around within a while.

Rose
:'(

 

Actually, you won't believe this but another of the corys now has a fluffy white growth above his eye...I read about a disease...called cotton something or other...anyway, him and the other cory are now in a quarintine tank, looking very miserable and I'm off to do the late-nght research mission (I live in New Zealand so its bedtime over here). Aaargh!

 

Your Cory with the cottony growth has a fish fungus. They need to be treated promptly with a fungus medication (I use the Fungus Clear Tank Buddies by Jungle Labs, but I am not aware of what may be available in New Zealand) Almost any of the Fungus Control medications on sale today would probably do some good. The only reason I use the Tank Buddies is that they are so easy to use. Since the rest of the fish have already been kind of exposed to it you will want to keep an eye on them to see that none of them come down with it as from what I have read it is quite contagious.

I hope this helps.

Rose