I recently lost two small butterfly koi within two weeks of putting in my pond. they had no visible signs of illness. My pond is two years old and well established in terms of amonia , nitrite, salt levels , etc.. I have approximately 15 koi/ oranda combination within the pond. It is 800 gallons. Yesturday I noticed one of my 10 inch koi was slowing down and seperating itself from the rest of the fish. This is the same thing that happened to the two butterfly kois I lost. Does anyone know what may be going on and how can I treat this especially the one that is ill. Thanx alot for your help.
Kathy

I'm sorry about your beautiful koi. It can be hard to determine what happened to the two new koi. It does sound like it may have been contagious as your other koi is now acting abnormal. In the future, try to quarantine new fish. What were the results of your water tests exactly? What kind of filtration and aeration do you have? How big are your koi? If you have many that are 10 inches or more, then the pond is over capacity. Experts say to have 1000 gallons for the first koi and 100 gallons for each additional koi. Koi can grow to 3 feet but most grow to about two feet. Your pond could have a few very young koi but eventually, you should build a larger pond or find homes for the larger koi. The crowding would worsen any problems that the new koi brought in. Unfortunately, being slow and lethargic could indicate most any problem such as water quality, bacterial problems, funguses, viruses, parasites, etc. Parasites and bacteria are pretty common with koi. If you contact your local pond or koi club, they might be able to examine your fish for signs of parasites.

What level of salt do you maintain? I suggest 0.1% if you don't have plants and 0.05% if you do. That helps with a lot of fish problems. Aside from that, be sure to filter and aerate the water really well. You might want to try some MelaFix. If you can diagnose a specific problem, you may need antibiotics and/or parasitic medications. You can use them without a diagnosis but keep in mind that some medications may kill good bacteria, mollusks, crustaceans, microorganisms, and/or insects. Regular partial water changes are also a good idea.

After the algae clearing up, we lost our most favorite goldfish. Also no signs of sickness/illness just lethargic. I've been watching one other lately. I finally put some salt in..and it looks like that did the trick. He's acting better and so far so good with all of them. Good luck for the rest of yours.

I'm sorry about your goldfish Sadie May.

If you can get a look at them I found this site that may help diagnose them. My pond is roughly the same size with about the same amount in it. I plan on giving some to my buddy starting a pond when I figure out which ones I am attached to. Enlarging the pond is also in the stars for me.......when I get a job again. :D
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