Figuring out what to do when something is going wrong.
There is little nastier than fish that have been dead for a while floating in your fish tank.
How to even tell if the problems with surviving fish are due to the same thing that killed the first fish or if the first dead fish just tainted the water causing poor water quality to weaken the later fish letting them sicken from opportunistic infections.
Here is what I pulled from my fish tank when I got home from my last gig.
Some are kinda long dead and others are only just dead. In the Bottom
left corner you can see the nasty looking gill on the smaller fish, that
seems to be common to all these dead fish. There are a couple still
swimming that appear to have that condition but they are still moving
well so I don't know if they will recover or if they will just die
And of course the excess food is to be expected as the dead fish were tainting the water so the other fish probably lost their apatite a bit. Even so, the water tests didn't show terrible levels. Only a slight trace of ammonia and nitrite (I call it a trace if the color is definitely below the .25 level but not quite perfectly 0.)
So, now I'm left with the worry about the remaining fish and if the condition will spread or if it will go away. What caused it? What should I do?
Answer for me is usually 1st, keep an eye on the water conditions and up filtration or water change if called for. I'll watch the surviving fish for signs of distress and monitor their eating. Last year I lost two catfish to unknown causes but they had a gill looking all nasty too so I suspect it is the same thing and since I had many fish survive then, I expect most of my fish to survive this time too. (This always seems to happen when I'm not home though.)
I'm kinda glad I have two totally separate systems now though in case something were to happen in one, the other is still separate.
I don't know what caused this. It is possible some wasp spray that some one (not knowing any better) used next to the system may have gotten into the system but I don't know if that would cause this. However, most fish diseases are ever present but the fish don't get sick unless their immune systems are compromised by stress or poor water quality or some other problem.
There have been some discussion or other posts about incidents that have happened to people to do with say a spilled feeder or power fail or other problems and one of the questions often is What to do?
First, remove dead fish and any excess flood possible.
Second, run water tests to see what the water quality situation is.
Third, Base feeding and water change decisions on the water quality and state of remaining fish if any.
Often running a system constant or extra cycles can help improve the water quality quicker if suffering from ammonia or nitrite spikes. 1 ppt of salt can help against nitrite spikes if there are surviving fish in the system. Salt levels appropriate to the type of fish and plants int he system can also help as a general tonic to stressed fish and improve their slime coat (this level is usually some where between 1 and 3 ppt.) Extra aeration and keeping a close eye on feed levels and all parameters of water quality are important after a stressful incident for the fish. Some injured fish may benefit from a salt dip but one must weigh the benefits of the salt dip against the extra stressed caused by handling. Some fish take handling much better than others. Tilapia usually survive extra handling quite well while catfish do better when left alone.
I've never personally experienced a total fish kill in any of my systems (I'm not counting the few tilapia I left in the outdoor tank to freeze to death last winter because I couldn't catch them all and I didn't have enough aquarium space for them, I knew they wouldn't survive.) All my non harvest deaths seem to have been from fish jumping out of water, pumps, pipe exploration, and some stress related illness (skin condition on catfish), Tilapia domestic violence, a few sick looking tilapia, tilapia fingerlings eating each other, very small catfish fingerlings dieing in cold water probably due to lack of energy reserves and not eating in 32 F water, and now this new condition of the catfish. Still with all this, I've never had a complete fish kill. (knock on wood)
It is always a bummer to loose fish but keep in mind that it will happen to all of us at one time or another. Been There, Done that, Got the Fillets in the Freezer. We are growing them to eat them after all so eventually you will kill fish. We just hope they are still fresh enough and big enough to be worth putting in the freezer or on the dinner plate. But take heart, even the ones that are not will make fine BSF larva feed which then make great chicken and fish feed so all is not lost.
Don't give up, get back on that sea horse and keep on with the Aquaponics.
I tend not to dwell too much on losses but move on to figuring out what to do next to improve things and try and see the benefits of the learning experience. I'm not bummed out too much by this though I might be if I were to loose an entire big tank full.