unclenedsfishfactory.com

We came home this evening to 2 of 3 Cory's dead and rotting as well as 1 4" Pleco and a 1" bull dog pleco in our 16 gallon tank. These fish were all very healthy and active on Friday evening when we left. We added a orange laser cory last weekend, the 3 cory's played in the bubbles all week, perfectly healthy and happy.

We replaced a heater Monday, and slowly raised the temp of the tank 75-78 degrees from 72ish when we discovered the old heater wasn't working. As I mentioned we added an orange laser Cory and 6 green tetras last Saturday and we added 2 foods for bottom feeders we picked up when we were in for the fish last week, both we have fed before as we mix them up for variety.

What ever killed them, it was fast, they looked like they had been dead for a several days, not just a couple. The large pleco had what looked like a jellyfish around him.

We have done a 50% water change, as the water smells horrible and I did a good cleaning of the bottom. Any ideas what could have caused almost all of our bottom feeders to die so quickly? We have a variety of tetras in the tank as well as a hilltop loach that are all fine.

Marcy

hard to say what happened...
I suggest you change another 50% in the morning
and 50% again tomorrow night

the 'jelly' was fungus devouring the dead pleco...
it had been dead for a long time

Will do the additional water changes tomorrow. They were fine Friday evening, all of them. The larger pleco had been out and about before we left.

So at most he was dead 2 days. It's just strange it was only the bottom feeders. Tetras, white clouds are all fine.

double check the actual heat with an acurate thermometer...
safe range is about 64-87 degrees F...
ideal is 77 for most tropicals...
another possibility is you had a power failure while you were away,
I don't know

We are not sure what is happening. This is or was an established tank with no issues.

We did the 2 additional water changes as suggested, all was fine yeseterday. Tonight we come home 1 tetra, 1 white cloud dead. We are now down to one Swenilli (sp) loach, orange cory, 1 white cloud, 5 tetras and 1 rummy nose. What ever is happening is fast and the fish give no warning signs. I checked everyone this morning, they were swiming around no signs of illness, etc. Come home 8 hours later to 2 more dead.

The temp is fine, tank has had 3 50% water changes and the fish until we find the dead are not showing any signs of illness, strange behaviour, nothing. No visable signs of injury, ick,etc.

Is there anything anyone can think of that moves this fast? something we should be medicating for?

Marcy

"...until we find the dead are not showing any signs of illness, strange behaviour, nothing. No visable signs of injury, ick,etc. "

very mysterious
and frustrating
...the deaths I hate the most are deaths with zero symptoms

the 2 fast moving diseases I can think of kill quickly but with obvious symptoms

with Costia (a large colony of microscopic parasites)
you get fin clamping, scratching, bloody patches
...can kill a whole tank in 2 days
...treat with copper or quinine or 3 teaspoons of salt per 1 gallon of water

with Malawi Plague (a flesh eating bacteria)
you get mouth fungus, then dorsal fungus, then body fungus
...can kill a whole tank in 3 days
...treat with Oxylinic Acid powder (the only thing that works)
...affects only Malawi cichlids that I've ever seen

sounds like environmental poisoning
(soap, insecticide, fumes from things like turpentine, windex,
bitter apple, witch hazel, a thousand other household chemicals)
...most poisons kill in 24 hours
and usually kill 90% of the tank
...treat with 100% water change
and high grade carbon or chemi-pure in the filter

it also seems like most of the fish that died
were cory cats and plecos

did some bad chemical get into your sinking food?

it can't hurt to treat for flukes

flukes can weaken fish and kill a few fish every 8 hours
also you can't see them without a microscope

I use a pink liquid called Lifebearer

we have it here, and the other drugs I mentioned

the large pleco was covered in that jellyfish fungus and the tank smelled horrible,

that was just ammonia from the rotting body
the fungus that breaks down the dead flesh is virtually never the pathogen that killed the fish

Do you think we should treat with salt or for flukes?

you can do both together,
can't hurt
(you just can't use salt with live plants)

another possibility,
(and now that I think of it, probably the most likely possibility)
is that the pleco just died from natural causes,
and was just so big, and made so much ammonia after death,
it's just taking a while for the fish to die from the ammonia poisoning...

among other things, ammonia damages the fish's gills

so they might be slowly suffocating, which would leave no obvious symptoms on the dead bodies.

2 things that reduce ammonia poisoning
are
adding salt
and lowering the pH,
however the damage may already have been done.

I'm kind of forming the opinion that the only thing you can do now
is hope the fish heal themselves in the new clean water
and wait