Buying Your First Koi: A No-Regrets Checklist

The worst koi mistakes are all made in the first month — usually at the moment of purchase. Here’s the path around them.

Before you buy a single fish

Your pond, not the fish, decides success. Minimum ~1,000 gallons for a small group, a cycled biological filter that has run for 4–6 weeks, and water testing (ammonia 0, nitrite 0). Buying koi the same weekend you fill the pond is the classic first-timer loss.

Choosing where to buy

This is where FindKoi does its job. On any dealer profile, check three things:

1. Quarantine practice — does the dealer isolate and test new stock (especially for KHV) before selling? “Not stated” means ask; our quarantine guide explains why this one question predicts heartbreak better than any other.
2. Community reputation — cited forum discussion, both praise and complaints.
3. Sourcing — domestic-bred vs. Japanese import; for a first pond, healthy domestic fish are the smart tier.

Then compare their bracket against the price guide so you know what a fair ask looks like.

Judging a fish in front of you

• Behavior first: active, upright, swimming with the group, eager at feeding. Skip the fish sulking alone at the bottom.
• Body: smooth symmetrical shape, no pinched head, no clamped fins, no missing scales, clear eyes, undamaged gill covers.
• Skin: bright and unblemished — no red streaks, ulcers, white cottony patches, or dusty film.
• Pattern last. Beginners buy pattern; keepers buy body and health. A plain, healthy Chagoi will outlive a stunning but stressed show-pattern fish — and befriend you besides.

Not sure what varieties you’re even looking at? The variety identifier sorts every color and pattern.

Quarantine even your first fish

New fish should spend 2–4 weeks in a separate tank before joining a pond — yes, even fish from a great dealer, and especially fish that will later share water with expensive ones. First purchase into an empty pond? That pond is your quarantine; just don’t add batch two the following weekend.

The realistic budget

For a first stocking: 3–5 domestic koi at $30–$100 each, plus a spare tank for quarantine. Resist the $500 import until year two — by then you’ll know your water, your filter, and your own judgment. When you’re ready, find a dealer near you.