Gold fish and koi dying

[T-Hbrand]

So I am running an aquaponics system and my golf fish and koi keep dying and I cannot figure out why. My PH is good and my water is clean. It started with me adding some new fish, they got ich but we treated that with salt air and temperature. That cleared up then I was given 2 small convicts and I had. I where else to but them so I put them in with the koi and goldfish. (Before anyone goes off on me on why you shouldn’t do this, I know now that was not smart for many reasons) I noticed after a bit that my gold fish, especially the smaller ones looked like there fins were being nipped so I removed the convicts but my gold fish started dying about 1 a day again starting with the smaller ones. I added some salt and did a water change and the issue continued. Lately they are dying and outwardly they look fine. I am down to 1 goldfish and 1 koi. They were the largest of about 25. Again my water perimeters are good. Could this be a virus or something that was brought on by stress? Any thoughts are welcome.

 

[J. H.]

You could have gotten bad ones. Bad genetics, flukes, etc. When buying goldfish & koi you need to buy from someone you trust, or at least QT & treat for parasites.

 

[Gourami Swami]

Do you test your water for ammonia, nitrite, nitrate? Do you know about the nitrogen cycle? What is the water volume of this system?

 

[T-Hbrand]

Do you test your water for ammonia, nitrite, nitrate? Do you know about the nitrogen cycle? What is the water volume of this system?

Do you test your water for ammonia, nitrite, nitrate? Do you know about the nitrogen cycle? What is the water volume of this system?

The ammonia, nitrate and nitrites are all at safe levels. I have a 65 gallon tank. Most of the gold fish were feeders. I was planning on using them to establish the tank but, I’m almost positive they brought something in with them. I was planning on moving the koi out when they got a bit bigger.

 

[T-Hbrand]

You could have gotten bad ones. Bad genetics, flukes, etc. When buying goldfish & koi you need to buy from someone you trust, or at least QT & treat for parasites.

So once things seem to have run there course is there anything I need to do to make he tank safe again before bringing in new fish?

 

[Gourami Swami]

The ammonia, nitrate and nitrites are all at safe levels. I have a 65 gallon tank. Most of the gold fish were feeders. I was planning on using them to establish the tank but, I’m almost positive they brought something in with them. I was planning on moving the koi out when they got a bit bigger.

Define safe levels, what were the test results? 25 goldfish and 2 convicts is a lot for a 65 gallon tank. How long was it cycled for before adding all those fish? I'm guessing your main problem has to do with the nitrogen cycle, bio-load of tank would take a huge stress with that many fish.
You are probably right about the feeders bringing something in with them, they usually are not treated well and often have parasites and disease.

 

[T-Hbrand]

Define safe levels, what were the test results? 25 goldfish and 2 convicts is a lot for a 65 gallon tank. How long was it cycled for before adding all those fish? I'm guessing your main problem has to do with the nitrogen cycle, bio-load of tank would take a huge stress with that many fish.
You are probably right about the feeders bringing something in with them, they usually are not treated well and often have parasites and disease.

The fish were added slowly over a few months. When I had the water tested numous times the person said it was the cleanest goldfish tank they had ever seen. The tank is not cycleing and all the gold fish and the convicts were quite small.

 

[Gourami Swami]

The fish were added slowly over a few months. When I had the water tested numous times the person said it was the cleanest goldfish tank they had ever seen. The tank is not cycleing and all the gold fish and the convicts were quite small.

I would recommend you buy your own test kit, and read up on the nitrogen cycle if you haven't. It's the bread and butter of keeping fish alive in aquariums.
Often the people at fish stores don't really know what they are doing. It is possible that this wasn't your problem, and the goldfish were all just sick. But without knowing what your water tests are like, we won't know, and will be hard to give advice for the future.

 

[duanes]

I'm guessing that the feeders were contaminated with some kind of parasite, bacteria or virus, and it overwhelmed the small space, and kept reinfecting.
Adding the aggressive convicts only added to the goldfish stress, compromising their immune systems further.
If it was bacterial, you may need to disinfect the entire system to start over. This would mean anywhere and anything the diseased water touched.
Quarantine is "the" most important facet of fish keeping, other than knowing the nitrogen cycle, because once something complicated enters, it is almost impossible to control in a closed system unless you have lab tests to determine what the parasite, bacteria, fungus or virus is.
And using feeders, you are almost assured of bringing something in, and all it takes is 1 phage to enter, multiply and an epidemic starts.
Ick is easy to treat, but in 50% of the cases, a secondary bacterial infection results from the lowered immunity brought on by ick, and can be nearly impossible to treat unless you can identify the bacterial species, and treat accordingly.
You would need to know whether the bacteria is gram + or gram - to select a treatment, and salt may or may not be effective depending on the bacterial species.
If its viral, there are basically no treatments that are effective.
Sorry to be so negative, but one must be a realist.

 

[T-Hbrand]

Alright thanks for your help guys. This is frustrating but very good to know.