24" square-cut universal replacement blade in galvanized steel. Fits all OWS windmills; corrosion- and warp-resistant so the head stays balanced. Use it to restore a damaged head or replace a thrown...

28" galvanized blade with the angled offset tip that builds the full 73" OWS head — the longest in the industry. The extra blade length adds torque, which is what lets these mills turn in 3–5 mph...

Two replacement tail arms with hardware for OWS large windmill aerator and yard-decor windmill heads. Not for garden-size windmills.

Replacement galvanized tailfin for OWS large aeration and yard windmills. A bent or missing tailfin stops the head from tracking the wind, and output falls off fast. Two-piece design makes the swap...

Pre-assembled one-piece replacement hub in powder-coated heavy-duty steel. The single-piece design eliminates the weak points of older multi-piece hubs and drops straight onto all OWS pond aerator...

Rebuild the whole business end of a windmill without buying a new mill. This universal assembly fits any windmill with a 1" shaft — OWS and most Canadian-made systems — and includes 12 heavy-duty...

The current-generation OWS windmill compressor, built on BalCam II technology: up to 4.5 CFM at 30 PSI — roughly triple the airflow of early-generation units. Stainless crankshaft, eccentric...

A pair of heavy-duty galvanized hinges that mount at the tower base so the whole windmill can be raised and lowered by tilting rather than climbing. The single most useful convenience add-on for head...

Heavy-duty screw-in ground anchors purpose-made for wood-tower windmills installed on dirt or grass. Anchoring stops tilt and shift in storms and soft ground — protecting not just the tower but the...

Brass two-way selector for balancing airflow between two diffusers or zones on a windmill or electric aeration system. Metering the split keeps both diffusers working evenly — no starved zone, no...

Puts a modern OWS aerator head on an old farm windmill tower — even one that's stood for 50–100 years. The steel receiver bolts or welds to the legacy tower, then accepts the current OWS windmill...

A small upgrade with an outsized effect in light wind: the head pivot bearing lets the windmill head swing to face the breeze with less resistance, so the mill tracks and starts sooner on calm days...

Outfits a windmill for 1–2 acre ponds with a two-zone diffuser layout. Includes a second airstone with foot valve, a two-way selector valve to balance airflow between the two stones, enough weighted...

The most-purchased windmill add-ons in one box, sized for ponds up to 1 acre: tower hinges for easy raising and lowering, weighted airline with hose connectors, an airstone housing bucket that keeps...

Bearing overhaul kit for non-OWS windmill compressors — note: this kit is not for OWS windmills. Each kit includes 3 bearings and 6 flanges sized for single and double diaphragm compressors on Gen 2...

Replacement bearings for the OWS windmill compressor. Choose the complete three-bearing replacement, or the individual side pillow-block or middle eccentric bearing if you're renewing a single worn...

An all-steel in-line relief valve that protects the compressor when the airline freezes, clogs, or kinks. Instead of letting backpressure burn out the compressor, the valve vents excess air...

Frozen airline is the classic winter failure on a windmill aerator: pressure builds, aeration stops, and the pond loses oxygen when fish need it most. The Freeze Control Unit prevents it...

The scheduled service kit for OWS windmill aerators. Every 4–6 years the compressor's wear parts should be renewed; this kit includes the diaphragms, valves, and seals for both BalCam I and BalCam II...

A complete new head for a windmill that already stands. This assembly replaces the entire working end of an aeration windmill — 73" blade set, tail, and BalCam II compressor — and is the standard fix...