Preventing Waterfall Freeze-Up in Missouri Winter

An 800-gal waterfall (600-gal reservoir) freezes solid in Missouri winter. Flow drops to a trickle. Fear of pump burnout. Can salt help?

The Physics: Moving Water Freezes Slower, But...

Flowing water resists freezing, but in sustained sub-freezing temps, ice builds at the edges, narrows the channel, increases velocity, and eventually bridges across. Once the reservoir level drops (ice displacement), the pump sucks air → overheats → burns out.

Salt: A Band-Aid, Not a Cure

1 lb solar/kosher salt per 100 gal lowers freeze point ~0.5°F. For 600 gal, you'd need 6+ lbs for a meaningful drop. It helps marginally but won't prevent freeze in a Missouri January. Salt also corrodes pump seals over time.

Real Solutions (Pick One)

1. Shut Down & Drain (Best for Seasonal Features)

• Pull pump, store indoors in bucket of water (seals stay wet).
• Drain lines, reservoir, waterfall.
• Zero freeze risk, zero electricity, pump lasts years longer.

2. Run Pump Continuously + De-Icer

• Pump must run 24/7. Moving water in pipes resists freezing.
• Add floating de-icer in reservoir (thermostatic, 1000W). Keeps intake area ice-free.
• Insulate exposed piping (foam pipe wrap).
• Risk: Power outage = instant freeze-up. Pump burns if run dry.

3. Convert to Winter Aeration Only

• Remove waterfall pump.
• Place air pump + diffuser at bottom of reservoir.
• Bubbles keep hole open, add O2, prevent stratification.
• Cheap, safe, reliable.

Recommendation

Shut it down. Missouri winters are too harsh for a small waterfall to run reliably without constant babysitting. Pull the pump in November, restart in March. Your pump will thank you.