Block UV & control algae
An opaque, UV-stabilized HDPE layer blocks sunlight at the surface, starving algae and cyanobacteria and limiting UV-driven reactions such as bromate formation.
Algae controlShade balls
Shade balls — and the heavy-duty shade ball, Armor Ball®
Shade balls are hollow plastic balls floated on water to block sunlight. Armor Ball® is the industrial-grade evolution: built thicker, heavier, and tougher to do far more than shade.
Cut evaporation
By covering most of the open water surface, a dense shade-ball layer cuts evaporative water loss up to 90% — the major secondary benefit that made shade balls famous.
Evaporation controlSuppress odor & VOCs
The floating barrier reduces the open surface from which odor, H₂S, and VOCs escape, easing nuisance complaints and regulatory pressure on open basins.
Odor & VOC controlDeter birds & wildlife
Removing the open-water surface deters waterfowl that contaminate water and, near airfields, create strike hazards.
Wildlife deterrentWho uses shade balls
Where a shade-ball cover fits
Shade balls cover any open liquid surface — reservoirs and water storage, mining and tailings ponds, frac and produced-water ponds, wastewater lagoons, agricultural and dairy lagoons, leachate ponds, and heated process tanks. See every vertical on the applications page.
The heavy-duty shade ball
Armor Ball® — engineered to do more than shade
Basic shade balls are usually thin-walled and intended mainly to block light. Armor Ball® is the industrial-grade evolution: a thicker-walled, reinforced HDPE ball that holds up on aggressive liquids — tailings, leachate, produced water, digester surfaces — not just clean reservoirs.
- Surface coverage
- 91%
- Ball weight (dry)
- 50 g
- Buoyancy
- 10.9 lb/ft² (53 kg/m²)
- Chemical resistance
- Excellent; inert to most industrial liquids (pH 2–13)
- Insulation
- R-2
- Life expectancy
- 25+ years
- Warranty
- 10 years (manufacturer)
- Installation
- Tool-free — pour onto the surface; self-interlocking; self-adjusting
Full confirmed specs on the Armor Ball® page · how a ball cover works →
Compare
Armor Ball® vs. commodity shade balls
Both are hollow plastic balls that float on a liquid surface, but Armor Ball® is engineered for industrial duty while commodity shade balls are typically thin-walled balls intended mainly to block light. This is a factual comparison.
| Attribute | Commodity shade balls | Armor Ball® |
|---|---|---|
| Construction | Thin-walled | Thicker-walled / reinforced HDPE |
| Weight per ball | 29–40 g | 50 g |
| Plastic / material | Mixed recycled (post-industrial or post-consumer), unverified source — often contaminated, oxidized, and weaker | Pure HDPE — virgin blended with traced, tested recycled HDPE; no other plastics mixed in |
| Primary purpose | Block sunlight | Heavy-duty floating cover (evaporation, UV, odor, insulation) |
| Surface coverage | Varies | 91% |
| Buoyancy | Not typically rated | 10.9 lb/ft² (53 kg/m²) |
| Chemical resistance | Limited | Excellent; inert across pH 2–13 |
| Operating temperature | Not typically rated | −70°F to +160°F |
| Insulation | None rated | R-2 |
| Wind rating | Not typically rated | 35 MPH (75 MPH for AQUA) |
| Life expectancy | Often 3–10 years | 25+ years |
| Warranty | Varies / none | 10 years (manufacturer) |
See the full breakdown: Armor Ball® vs. shade balls →
Background
Where the shade-ball idea became famous
The concept entered the public eye through the Los Angeles Department of Water and Power, which deployed roughly 96 million balls on the LA Reservoir (first trialed at the Ivanhoe Reservoir in 2008). The primary driver there was preventing bromate formation, with UV/algae control and evaporation reduction as additional benefits.
We reference that deployment as category background, the way the rest of the industry does. Armor Ball® is AWTT's industrial-grade shade ball.
More in the Knowledge Hub: What are shade balls? · Do shade balls save water? · Bromate & UV byproducts
FAQ
Shade balls — questions answered
What are shade balls?
Shade balls are hollow plastic balls — typically high-density polyethylene (HDPE) — floated on the surface of a body of water so that, en masse, they block sunlight from reaching the water below. Poured onto a surface, they self-arrange into a dense floating layer that shades the water without anchoring or mechanical structure.
Do shade balls actually work?
Yes. A dense shade-ball layer blocks the sunlight that drives algae growth and UV reactions such as bromate formation, and by removing most of the open water surface it cuts evaporation up to 90% per AWTT published data. Armor Ball® achieves this with 91% surface coverage.
Do shade balls save water?
Yes. Evaporation happens at the open water surface, so covering 91% of it removes most of the area where water is lost. Armor Ball® shade balls cut evaporative loss up to 90% per AWTT published data — an uncovered 5-acre pond losing over 1,000,000 gallons a year can keep the large majority of that water.
How many shade balls do I need?
Plan about 10 balls per square foot (108 per m²) for a full cover. A 1-acre pond (43,560 ft²) needs roughly 435,600 balls. Use the coverage calculator for an exact figure for your surface area.
Are shade balls safe for drinking water?
Armor Ball® shade balls are molded from UV-stabilized HDPE specified for potable-water/food-contact use when required, with material certifications, SDS, and NSF/ANSI 61 documentation where applicable available on request.
How is Armor Ball® different from commodity shade balls?
Armor Ball® is a thicker-walled, reinforced HDPE shade ball engineered for industrial duty: 91% coverage, 10.9 lb/ft² buoyancy, chemical resistance across pH 2–13, R-2 insulation, a −70°F to +160°F range, a 25+ year life, and a 10-year warranty — versus thin-wall commodity shade balls (29–40 g) intended mainly to block light.
Get a custom Armor Ball® quote
Tell us about your site — surface area, liquid, and goals — and we'll size a cover and respond within 24 hours.
Manufactured by AWTT · 700+ installations · 25 countries · 10-year warranty