500-Gal Pond Green Water: UV Clarifier Solution

500-gal pond, lattice cover (good sun/shade), 60% plant cover reduced to lilies only. Microbe-Lift, Algaefix tried. 900 gph pump, filter cleaned 4–5 days. pH 6.5. Fish fine. Can't clear green water.

Green Water = Free-Floating Algae

Plants/chemicals don't touch it. UV clarifier is the only reliable cure. Exposes algae to UV-C, prevents reproduction, kills cells.

Specs

• Flow rate: 900 gph → need UV rated for ~1,000 gph.
• Wattage: ~8–15 W for 500 gal.
• Install after filter, before return.
• Replace bulb annually.

Nutrient control (less feeding, more plants, water changes) helps long-term. UV clears in 3–7 days.