sick bronze cory

[TheFighterFish]

I woke today and found one of my corycats laying on its side. I assumed it was then but when I tried to remove it, it jumped back to life. I fed some food, but it ate very little. A few minutes later, it laid down on its side. Seeing it a second time, I quickly moved it to my fry tank. The tank that I removed it from (10G) has:

PH 7.2
Alk 100 ppm
Hard 150 ppm
Nitrite 0
Nitrate 10

It's quite a new tank, so I could be going through a cycle. That was why I put the cory in my 5...it's been set up for at least 2 months. The cory doesn't have any problems on the outside. No fungus or anything...

any suggestions on what it could be?

 

[TheFighterFish]

This is too bad...it doesn't look like he's gonna make it. His swimming contour is unpredictable the only thing moving now are its eyes. Must have been an internal disease.

1st casualty since I restarted the tank in February.

 

[UP UP AND GUPPY]

Well he could be dieing of ammonia spike, you need to get an ammonia test so ou can find out what it is for sure.

 

[Lotus]

A small water change might help.

 

[UP UP AND GUPPY]

Yeah, water changes cant hurt.

 

[TheFighterFish]

It's happening again. One of three of my corycats are sick. The rest of the fish are fine. Externally nothing looks wrong. I always thought bronze corys were supposed to be hardy. I was about to give it the shock treatment (cold water), but now it swims fine.

I could test my water, but I'm confident that isn't the cause of the sickness. Again, I'm perplexed at one it only hits one corycat at a time.

Edit: it doesn't look so good actually.

 

[TheFighterFish]

Everything looks fine this morning. I think maybe that the fish was just hungry. Whoops.

Edit: Arg fish...It's near its time. Loss in color. Swimming around in spirals. I'm think swim bladder but I could be wrong. Gave it the cold water shock treatment. Went cold in a few seconds. Too bad. RIP

 

[TheFighterFish]

It's happening again. Somehow, something is killing of my bronze corys one by one. I just changed the water yesterday. All of my other fish are healthy.
I just can't explain it.

I'm thinking it could be the fish itself. All of my cories I got from my LFS.

The symptoms are a lose in color and an inability to swim properly. Fins are not erected.

 

[TheFighterFish]

Now I'm down to one corycat. So I think it could be the tank and tranferred him to the 5 G. I checked my water parameters today (10G) and had some weird results.

100 ppm hardness
7.4 PH