Is my cory dying?

[Big Al]

Hi. For the last week my peppered cory has seemed to loose weight, got very pale, lost his shine. sometimes i found him stuck to the filter, then i would turn it off he would swim away. this time he's been on the filter all night. I think i sould put him down but i'm not sure. the other one seems fine. There is no external signs of disease, he just seems weak. Please help!
~Biggy

 

[congealedmeat]

likely Al, that's what mine have done when they died.

 

[Puffernewbee]

I hate to jump in on your thread Al but I have an albino cory that is doing the same thing. Just last week he was swimming all over the place and now he just lays on his side on the bottom. If I try to net him he swims around like a mad man in then goes back to the bottom. My daughter said he was stuck to the filter a few days ago but then swam off. Like you, mine has no signs of injury other than his belly fins (Like that scientific speak) are a bit worn.

 

[Big Al]

Unfortunately, nobody can help him now. :sad I netted him without any problems today. He moved a little and then that was it. Poor guy. I have only 1 other, whom already seems lonely. Should i get a new one right away or should i wait? Thanks again.
~Biggy

 

[mister ben]

I had a similar problem recently with two of my panda cories. Since my water was perfect and I had good filtration, aeration, feeding habits, coverage, no visible signs of disease and nobody was harassing them, I saw no reason for the sudden deaths.

Then my lfs reminded me about anaerobic pockets within my substrate. Basically, they can be quite toxic to bottom dwellers and unless you are vacuuming or at least disturbing your substrate in some way, that may be the cause. How thick is your substrate? The thicker the substrate, the easier it is for the pockets to form. Mine is quite thick.

If you determine this was the problem, you can get a basic gravel vac that works simply on syphoning principles (no mechanical or electronic parts) for about 5 bucks.

 

[Big Al]

thx mister ben, my gravel is actually thick about 5" , I try and disturb it all when I do my weekly syphoning, but maybe i'm not getting deep enough, I use pea gravel mixed with medium size gravel so it shouldn't compact too much, maybe he just wasn't a good specimen, all my other fish seem very happy. I'll try some more. Thx again
~Biggy