burky0002,

You know it's fish lice? Did you see indicators to lead you that way? Usually this time of year (coming out of winter/ water warming up) it is usually a fungal/ bacteria problem that attacks our fish before they can build up their defenses.

I am presently fighting a bacterial /fungal thing in my 6,000 gallon pond with salt. The fish I was able to catch showed no nasties under the microscope and some fin rot.

Whatever it turns out to be, best of luck treating it.

LP

Here is a link that might be useful: Fish Parasites 101

what do you mean by flashing?Does that mean the fish flip over on their side,then upright themselves?

Fish lice is easy to identify in that you can see them with your eye and they are easily treated with demilin or fluke tabs.
Mike

Lots of things cause fish to flash other than parasites. And if it IS parasites, flashing is normally caused by flukes and not lice. Lice can be seen pretty easily, especially on the fins. they are small....about the size of a grain of rice only they are roundish and algae/brown colored. Flukes are not visible to the naked eye. Flashing is caused by anything that irritates the koi. Water quality (especially pH or ammonia) is the most common culprit. Don't treat until you know what you are treating for.