Backyard Aquaponics
A place to discuss aquaponics

I found this guy stuck to the SLO in my fish tank. I turned the system off for a minute to stop water flow and he floated to the surface. I'm not sure how long he's been dead for.

I recently (last week) added a bunch more channel cats to my system... went from approx 23 to 45. There's also one adult male tilapia about 12-13" long that was added. 500 gallon tank (8ft x 5ft x 2ft). Ammonia, nitrites, and nitrates are at 0. pH is at 7.2. Water was salted to about 0.5 part per thousand. After discovering the dead guy I thought it might be a disease since his fins are okay, so I salted another 0.5 ppt up to about 1ppt.

Can anyone give me some leads on what the problem might be?

Thanks!

All I can give you is a guess, I think he's probably been dead for a while (probably too long to tell anything). If the others are acting normal and you've salted then I wouldn't be too concerned. Just keep your eyes on the remaining catfish for anything odd (flashing, gasping, overly aggressive fish). Probably just stress from the new environment though.

Looks like a fungal thing to me.

Was it alive with the fuzzy stuff on it? Or did it develop once it died?

My catfish don't like to be seen so it's kind of hard to keep tabs on them, but I have not noticed any behavior indicators of disease or problems. I only have the API freshwater test kit... should I possibly be testing for other stuff that might be causing problems?

There are other things you can test but I don't think it would help in this case.

I doubt a lab could tell you anything about what caused the death of this fish in it's current condition but it's possible (rarely worth the cost though).

Depending on the depth of your tank you might catch a glimpse of your catfish just before nightfall or early in the morning. Mine hide during the day also.

Just make sure there isn't lots of uneaten food on the bottom of the tank, and solids aren't settling in the tank.

Fungal things can flare up if there is lots of uneaten food at the bottom of a tank.

Fish rot from the head first, it would only take no more than a day to progress to that stage....

do catfish prefer a good current or still water where they hang out.?

They hang out all in one corner of the tank. I really need to get a video of this but imagine a ball of earthworms or a snake ball, then picture that with channel catfish instead. The corner where they hang has the least water movement though. The other corner that is shaded has the discharge pipe from the other tank flowing in.

I'm wondering if perhaps I don't have enough filtration overall and the ammonia spikes at some points? I haven't tested frequently but the tests over the last 3 weeks have shown 0's across the board. I have four lava rock (scoria)-filled grow beds that are about 70 liters of rock, with water up to about 3cm below the top, so figure about 55-60 liters of submerged lava rock per bed. say about 240 liters total, for 45 catfish @ 4-6" long, one 12-14" tilapia, and some feeder guppies and goldfish.

so I'm imagining any uneaten food will also end up over where the catfish hang out, getting pushed and swirled until it also finds the least amount of flow.. that's either an energy saving ploy by the catfish to hang there and wait for the food to come to them or they just don't like flow, I like to think its an energy saving location.. but as Colum said, uneaten food can flare up a fungal problem... add that to fish hanging in the same place with minimal flow is not good.

In the past I filled up a 20lte bucket with scoria, it then took 12ltes of water to fill that bucket. 40% of my GB is scoria.
do that with your scoria and see how much water is circulating every hour compared to the size of your FT.

Too hard to tell since the fish has been dead for a couple of days at least based on the decay of the eyes. Salting is a good option-you might want to bump it to 2ppt.

How many square feet of grow beds do you have? Sounds like you don't have enough grow space for that many fish...

So, I've lost two more channel cats over the last few days. Both of them were missing almost all of their barbels (whiskers). I'm wondering if they are fighting or if my large male tilapia is nipping at them? Could large goldfish (6"+) be aggressive towards the smaller cats?

Not a clue on this one Cathode . My catfish and Bluegill seem to get along well but I did loose some to aggression by other catfish and others to disease. They seem delicate compared to the bluegill and even trout. I think it's partly because they like warm water and my system is a bit cool most of the year.

Yet another channel cat dead today, this one quite a bit bigger (7-8"). I've had it! Went to LFS and bought two used 40-gallon aquariums for $24/ea, will move my guppies to those tanks.

I waited until light had been out for an hour and went out with a flashlight to my tank. I'm really glad that tilapia sleep at night. I was actually able to slip the net underneath him and slowly lift to the surface. He didn't even wake up until right before I pulled the net out of the water.

I put the tilapia in the 100-something gallon jacuzzi tub. I suppose in the future I can use that as a breeding tank for tilapia (or anything else).

If my catfish cease dying after tonight, I'll assume it was the tilapia attacking them. If I still have catfish dying, I'll have to go back to the drawing board...

Hi cathode
Check out this post by TCLynx:Re: HSM Disease, Disaster and recovery

No catfish deaths but they aren't feeding either. I suppose they are traumatized by how long it took me to net the tilapia out of the tank...