Seasonal pond care

Pond care in Winter

Winter pond tasks

1NO feeding (koi metabolism stops below 50°F)

2Install floating de-icer to maintain ice-free hole for gas exchange

3Run aerator at LOW level near surface (not bottom - destroys thermal stratification)

4Cover pond with insulation if pond is shallow (under 3 ft)

5Visually check fish weekly through ice-free hole

6NO water changes

7Resist trying to wake fish - they go dormant naturally

Other seasons

Browse all 4 seasonal pond care guides. Pair with the koi pond setup guide.

Pond keeping fundamentals

Pond keeping differs from aquarium keeping in three core ways: 1) Seasonal swings - pond water temperature swings 30-60°F between summer + winter, meaning fish metabolism, feeding, and disease pressure all change with the season. 2) Larger water volumes - parameters change more slowly but recovery from a crash is also slower. 3) Open environment - leaves, predators, fertilizer runoff, and weather impact ponds in ways aquariums never experience.

The seasonal calendar drives everything. Spring is the highest-stress period for koi - waking metabolism + parasite-friendly water temps + low immunity create perfect conditions for outbreaks. Summer is the active growing/feeding season. Fall is winterization - de-stocking, leaf netting, food transition. Winter is monitoring + ice prevention.

For pond services in your area, see our pond installation, pond maintenance, pond survey, and fish stocking directories. For DIY, see our pond pump sizing calculator.

Frequently asked questions

How deep should my pond be? Minimum 4 feet for koi in most US climates. Deeper in northern zones (5-6 ft prevents complete freeze). Shallower can work in southern zones but leaves fish vulnerable to temperature extremes.

How many koi can I keep? 1 inch of full-grown koi per 10 gallons of pond water. A 24-inch koi needs 240 gallons. Most adult koi reach 18-24" so plan accordingly. Use our best pond fish guide.

Do I need a UV sterilizer? Yes if you fight green water. UV kills free-floating algae + many parasites. Size for tank turnover - 9-13W per 1,000 gallons. See UV sterilizer sizing calculator.

How do I prevent heron + raccoon predators? Heron decoys (move weekly), motion-activated sprinklers, netting over the pond, depth (herons can't hunt in 3+ ft water).

How often should I drain my pond? Full drain every 5-7 years for cleaning + repairs. Annual partial drain (30%) for winter prep + filter media swap.