If you only see one fish w/ issues...pull it and treat it.

You really, really, really don't want to treat the whole pond. Why? Remember all that time you devoted to getting the right biological cycle established in your pond? And the green water while you waited? And the muddy water you couldn't see your fish through?

Anything you treat an ulcer on a fish with in that water will also kill your biological colonies in the pond.

You'll be back to the stage where you finally put water in the pond that first day.

Sick/injured fish should be removed from the pond and treated. Buy a small preformed pond, fill it with (a tiny bit of) water and treat your fish where 1) you will use less medications because you have less water, 2) you can observe the sick fish much more closely, and 3) you can save the established biological colonies of your large pond.

There are medicated fish foods that are designed for this problem. I have used it successfully. I don't remember the names. Do a search.

I would question the opinion though, especially if the injuries are about the same location on both sides. The fish might have been injured trying to go through a too small space. I have several comets who persisted in going through the openings in a plastic crate that were too small. They now have white spots where the injuries occurred. I took out the crates, no more symmetrical injuries. Similar injuries can occur if they get sucked into an inlet hose.

I will do a search for the medicated fish food as well as see about getting a small tub to try treating the fish. Last night I trimmed the parrot feather back at one end of the pond which will make it easier to try netting the injured fish. It will also make it easier to inspect the rest of the fish for injuries while I feed them.

There is a crate which has a bunch of round holes of varying size that's in the bottom of the pond holding up a waterlily pot and a large concrete paver. The crate and paver are also there to give the fish somewhere to hide if a predator goes after them. I hadn't thought about the fish injuring itself on that. At this time of the year that crate is nearly impossible to get at due to all the waterlilies and parrot feather in the pond.

Thank you for the advice! Between this and the book I bought last night, Koi For Dummies, I will hopefully be able to get through this without accidently killing any of the fish or screwing up the pond!

Will vacuming up the muck at the bottom of the pond mess up the biological balance of the pond?

Kara

Kara - vacuuming should be fine...you're just sucking stuff up. I'm not sure how big your goldfish is but it may be easier to just use a 10 gallon tank...that's what I do for my small guys. That way you can get a full view of their body and see how they are healing. You can get a cheapo 10 gallon tank w/ a small bubbler..that's all you'll need. Cover half the tank w/ a towel to give it a "cave" to hide. PLUS...a lot of meds in smaller quantities give you 10 gallon dosing so it's easy to treat. Aquarium salt does wonders for wounds...that and clean water (!!!).

Medicated food: I use Medikoi - purchased at PondRx....I'm sure there are other places but their shipping is FAST. It sinks to the bottom so you don't need to worry about them coming to the top to eat it if they are tending to stay toward the bottom.