Hello. I need help

[Rich C]

Hello. My name is Rich. I have an 8000 gallon pond in central NJ. The pond is one year old. Water is quality is good and clear.
I have a problem. After I built the pond and let the water settle, I did acquire fish. I purchased five large koi and they settled in with no problems. We had a very mild winter and everything was fine in the spring. About a month ago I did notice one of my larger fish acting strange. This fish, photographed, would remain seperate from the group. I have approximately 50 fish in the pond. This fish would stay off to the side, mostly in the shaded area. It would come over to feed but would only eat a few pieces and then float away. This fish would mostly stay on that plant shelf area of the pond, with it's head touching the bottom and the tail at the top of the water. If the fish swims into the deeper part of the pond, it would stay at the surface. I have noticed that the fins on this fish appear to be slghtly torn and ratty looking, nothing too severe, does not appear to be rot. Today I noticed that the eyes of the fish are clouded over and it appears to have a slime coat that is flaking off. There is some scale damage by the tail.
This is one of the five largest fish in the pond and all of the other fish are acting normal. .
Salt level is at 10 percent.
Any assistance, advice would be appreciated.

 

[sissy]

You may want to take him out and treat him in a seperate tank as it really looks like fin rot to me .I am in no way an expert and only seen it in videos on you tube .If i remember tetracycalin was used to treat the fish you may be able to get the you tube video .

 

[Mmathis]

What is fin rot?

 

[Waterbug]

Salt level is at 10 percent.

Seriously? I'm not sure of the effect of that much salt because I never heard of such a level, but assume that would cause the slime coat to appear to be coming off and the cloudy eyes. Maybe even burn off the fins.

Here's some good info imo on keeping salt in a pond. But there are other opinions on keeping salt in the pond.

Beyond that...what are the water test results for ammonia, nitrite, pH and KH?

In the mean time here is a good video imo.

 

[sissy]

I only add like a cup when it rains alot and only add that when I think it may need it .I could never really understand lots of salt because they are not salt water fish .I even saw on you tube where the guy adds a 50 lb bag of salt to his 3000 gallon pond pond .Not sure if his fish lived but never saw another video by him .He was just throwing it in .I dilute mine .

 

[Waterbug]

50 lbs of salt in 3000 gal would be a 0.2% salt level. For treating fish 0.2% would be low and many plants could live at 0.2% salt.

For the OP to get to 10% salt a total of 6,667 lbs of salt, over 3 tons, would have to have been added. Seems unlikely, but I don't know the details, just what's reported.

Dumping salt directly into the pond or stream is my preferred method. Fish can take fairly high levels of salt for limited time period and given good water movement the localized areas of high salt shouldn't be much. Diluting salt first can be an issue but not when you're talking about just a cup. But 50 lbs dissolved in say a 55 gal drum and dumping that into a pond would really raise local salt levels to high levels until it mixed with the water. So it's safer imo to let the salt dissolve on it's own in the pond or in a stream when adding a serious amount.

Just for the record...I'm not advocating adding salt to ponds.

 

[Rich C]

Fat fingers. Salt content is 1.0%, not 10%. I add salt into the two skimmer boxes that I have and into the large waterfall. I do sprinkle the remaining salt around the edges of the pond on the plant shelf and I have not observed any significant plant problems.
My numbers, PH is 8.0 and does not fluctuate, Phoshpate test is 1.0, Nitrite test is .2 and Ammonia is 0. I have approximately fifty fish and rough dimensions of the pond is 30ft x 11ft a 2ft and 3ft depths.
In regards to the need to add salt, I have observed leeches in my skimmer boxes and adding the salt after I complete a clean out and water change has controlled this problem. I clean out and chang, approximately 10% of the water. I have well water with no chemical filters, only a paper filter to control odor.

 

[Waterbug]

That makes more sense.

It is of course impossible to diagnose a fish in a forum...hard enough in person. From what you've described it could be anything from bacterial to parasitic, even chemical (I doubt chemical). IMO it's best to just work thru the steps provided by Dr Johnson.

Do keep in mind that some treatments can't be used with salt.

The 0.2 ppm nitrite level is a problem. For this time of year it should be zero. I would double check the result before taking action just to confirm, but long term that level of nitrite is going to cause problems. The nitrite level probably has nothing to do with this particular fish's problem, but it could. When a fish has a bacterial and/or parasite problem the question shouldn't really be how to cure the problem but why is it a problem. Healthy fish, like people, can fight off bacteria and most parasites. In most cases a sick fish's problem starts with poor water. Maybe this fish was just the weakest and is the first of many to have problems. Maybe this fish just had poor genes. Can't say. But fixing water problems is a good start and something that's easier to do than diagnose a fish.

The nitrite problem would point to a bio filtering problem. Poor filter or not enough.