Mystery disease has nearly wiped out my whole tank! Please help

Cave

Small Fish
Mar 26, 2005
43
0
0
#1
Hi all

I have a Rio 125 community tank (that's 30 gal with an internal filter). The fish are a complete mix and match. Some little shoals a tetra, a few random catfish and loaches. The biggest fish in there is a siamese algae eater which is about 4".

Last Saturday I put in a little shoal of rocket pencil fish (about five) and a little shoal of ember tetra (6 or 8). The next day, fish deaths! The pencil fish went first.. all within the first few days. I do not believe the tank was overcrowded. Even if it does have a few more fish than is strictly recommended, it's been more crowded in the past with no problems at all.

The next to die were my hatchet fish. A female betta. The gold tetras. Most of the glass catfish. A few of the ember tetras. Today, another tetra and the banjo catfish. I have hardly anything left!

Some of the fish had a grey slime on them before they died, or gasped at the surface, which made me think slime disease (a parasite I think?). But some looked perfectly fine, and died very suddenly with no outward symptoms - no bloating, no dropsy, no erratic swimming, no gasping. Can slime disease some times kill with no apparent symptoms?

Water parameters are NORMAL. The temperature is a little high at 28C. I'm not sure if this is different to normal for my tank because while everyone is healthy I don't pay attention to it. Turning down the heater made no difference to the water temperature and my room temperature is much lower, so I can only think the temperature increase is caused by the lights (it does go down to 26 over night). I'm not sure if this could cause the deaths though.

I'm getting really desperate. I put some whitespot/velvet treatment in just now. The treatment is called eSHa EXIT and it doesn't say on it anywhere what the active ingredient is, but I figured since it kills whitespot it might work on the parasite causing slime disease. And even if it doesn't, there's not much left to lose!

Can anyone suggest what the problem could be? Is slime disease the likely culprit, even on the apparently un-slimed deaths?
 

Lotus

Ultimate Fish
Moderator
Aug 26, 2003
15,115
13
38
Southern California
home.earthlink.net
#2
It sounds like something bacterial to me. If you're not seeing any parasites, then it's probably not parasites. A parasitic disease would also kill a lot more slowly. The other option is a viral infection, for which there are no known treatments.

You don't mention any other treatments than the EXIT, so I'm assuming you didn't treat for slime disease.
 

sphed

Large Fish
Feb 14, 2007
166
0
0
#3
Try doing a 30% water change and remove the fish that seem to be infected if its spreading and killing that fast.