Building a backyard koi pond turns a corner of your yard into a quiet living space. Here’s how to design, build, and stock one that survives Kansas summers and winters.
Pick the Right Size
For koi specifically: minimum 1,000 gallons and at least 4 feet deep. Koi grow big — adults hit 18–24 inches — and they need space, depth, and cool water in summer plus protection from freezing in winter.
Quick rule: 250 gallons per adult koi. A 1,000-gallon pond comfortably holds 4 mature koi or 6–8 juveniles.
Picking the Location
- Partial shade — direct all-day Kansas sun cooks the water and grows algae like crazy
- Away from large trees — leaves and roots are a nightmare
- Visible from where you sit — what’s the point of a pond you can’t see?
- Power access — pumps and filters need outlets
- Not at the lowest point in the yard — runoff brings fertilizer and chemicals from your lawn
Liner vs. Preformed
- Flexible EPDM liner: Custom shape, larger size, longer lifespan (20+ years). The standard choice for serious koi ponds.
- Preformed plastic shells: Cheaper, faster to install, but limited in size and shape. Good for smaller starter ponds.
Filtration — Don’t Skimp Here
Koi are heavy waste producers. Under-filter and you’ll fight algae, ammonia, and dead fish all summer.
- Mechanical filter — catches leaves, sludge, debris (skimmer + pre-filter)
- Biological filter — bacteria that convert ammonia to nitrate
- UV clarifier — kills suspended algae, keeps water crystal clear
- Pump rated to turn the entire pond volume every 1–2 hours
Kansas Winter Prep
Wichita winters freeze ponds. Koi survive under ice if:
- Pond is at least 4 feet deep at the deepest point
- You keep a hole open in the ice for gas exchange — pond de-icer or floating heater
- You stop feeding once water drops below 50°F — koi metabolism shuts down
🧊 Don’t Smash the Ice
Hitting the ice with a hammer to break it sends shockwaves through the water that stun or kill your fish. Use a de-icer or pour hot water to melt a hole gently.
Stocking Your Pond With Koi
Mr. Mc’s Market stocks koi in multiple varieties — Kohaku (white/red), Sanke (white/red/black), Showa, butterfly koi, metallic yellow Yamabuki Ogon, and more. See our cichlids & koi page for details.
Start with juveniles (4–6 inches) — they’re cheaper, healthier, and you’ll watch them grow into the pond. Add fish in groups of 2–4 over several weeks, not all at once.
Pond Supplies
We stock everything for backyard ponds in our Pond section — koi food, water treatments, bacterial cultures, algae control, and de-icers for winter. For algae issues, see our Kansas pond algae guide.
Visit Mr. Mc’s Market
📍 1901 E 21st St N
Wichita, KS 67214
🕐 Open 9 AM – 9 PM, 7 days a week