Microbe-Lift Ich Out 32oz.
Quite possibly the most common malady affecting pond fish, ich (white spot disease) has good options for treatment. Microbe-lift is a great name in pond supplies and they have a great ich product called “Ich Out”. You will have to remove the carbon filter from your system prior to use and do water changes after use but your fish will thank you for it. If left untreated, ich protozoan will attach to your koi, dig into the skin and feed off the tissue and which makes your fish vulnerable to additional infections.
Furthermore, if they are allowed to run the course of their life cycle, they will drop off after a while and fall to the bottom to reproduce thus starting the process over again. You will want to deal with ich as soon as you can and Ich Out is a good start. Ultimately, you will want to get your water chemistry back in balance as ich typically does best in poor water quality.