Baby Koi Winter Survival in Deep Washington Pond: Surface Pump, De-icer & Feeding

23×18×8 ft pond, 2–4.5" baby koi, WA winter — treat babies like adults. Move pump to 12" depth or add de-icer. Don't overthink.

Winter Setup

1. Pump at surface (12"): Recycles cold top water, preserves warm bottom (39°F).
2. OR floating de-icer: Keeps 12" hole open for gas exchange.
3. Air stone at depth: Gentle bubbles — no super-cooling.
4. Stop feeding at 50°F: Babies too — their metabolism stops.
5. Low-protein fall food until 50°F — then nothing.

Why Babies Are Fine

• 8 ft depth = massive thermal reserve.
• Waterfall (13 ft head) + air stone = high O₂.
• Undergravel filter + pea gravel = stable biology.
• Koi evolved for this — babies included.

Don't

• Run pump at bottom — mixes cold top with warm bottom.
• Feed in winter — undigested food rots, kills.
• Panic — they're in a palace.

Your pond is a koi paradise. The babies will thrive. Keep it simple.