KoiCrisis — Koi and Pond Fish Help

PLEASE think about this image and these concepts until you understand them.
This will break your habit of looking for a pill or a drop for a fish illness.

What it represents is that a combination of factors has to fit together to cause disease in your fish. When you called my office about fish with sores, we sent you here to learn that it’s more than just a bacterial infection. THREE things fit together to cause disease.

For example: Cold Water¹, Crowding², and Parasites³ on the new fish you didn’t quarantine.

Start here if your koi is acting wrong

If you’re here because something changed fast, use the Symptoms section first and work outward.

Quick reality check

  • Most problems are stress + parasites + water quality, in some order.
  • If you can scope fish, great. If you can’t, you still need a plan that isn’t fantasy.
  • Big swings and “shotgun” chaos usually make it worse.

Venn Diagram

Venn diagram showing Your Pond Conditions, Your Fish Conditions, and Your Fish Pathogens. Disease occurs where all three overlap.
Three factors ALWAYS coincide to cause disease.

About this site

KoiCrisis is a library. Some pages are old. The fish biology didn’t change. Some product names and trends did. If something looks dated, it probably is — but the point is the information, not the paint.

If you’re new to this: start with Symptoms and Water Quality. Most “mystery diseases” stop being mysterious once you slow down and test the basics.

Related resources (optional)

These aren’t required to use KoiCrisis. They’re just other resources in the same orbit.

Aqua Meds

Koi & Pond Care products and support.

Visit Aqua Meds

SickKoi

Fast, practical triage for sick koi.

Visit SickKoi