Koi can get sick. This is a fact that most beginning hobbyists learn the hard way. As the saying goes, an ounce of prevention is equal to a pound of cure. With Koi, the whole idea behind keeping this type of fish is their beauty. The best way to ruin a Koi's beauty is by getting a parasite or bacterial infection that can leave a scar for life. The #1 best way to keep a Koi beautiful and healthy is good water quality. Good water quality can be obtained by having a good filter system. These pages contain information on all of the most common diseases and ailments that can harm a Koi.
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