How to Choose the Right Floating Cover — Selection Guide for Ponds, Tanks & Reservoirs
Choosing the right floating cover depends on five factors: your primary objective (evaporation control, algae prevention, odor containment, thermal insulation, or wildlife exclusion), the wind exposure at your site, whether you need potable-water-safe materials, your insulation requirements, and your budget. AWTT manufactures six modular floating cover products — each engineered for a different combination of these factors. This guide walks you through the decision framework engineers and facility operators use to select the right cover.
Five Selection Criteria
Every floating cover selection decision boils down to these five variables. Understanding how your site scores on each one will narrow the field to one or two products.
1 Primary Objective
What is the single most important problem you are trying to solve? Your answer determines which performance specs matter most.
- Evaporation reduction — All products reduce evaporation. For maximum performance (up to 98%), choose Rhombo Hexoshield.
- Algae prevention — Requires high surface coverage to block sunlight. Hexprotect AQUA (99%) and Hexprotect SLIM (99%) are the top choices.
- Odor/VOC containment — Needs high coverage plus wind resistance to keep tiles in place during gas release events. Hexprotect AQUA is the best fit.
- Thermal insulation — Hexprotect MAX R (R-17+) provides the highest insulation; Rhombo Hexoshield 189 (R-8) adds strong wind resistance.
- Wildlife / bird exclusion — Any full-coverage product eliminates the open-water landing surface that attracts birds. Higher coverage percentage = more effective deterrent.
2 Wind Exposure
Wind is the number-one threat to floating cover performance. Under-specifying for wind is the most common sizing mistake. Always design for the maximum sustained wind speed at your site, not the average.
Sheltered (< 40 MPH)
Tree-lined ponds, bermed lagoons, enclosed tanks
Any product works: Armor Ball, Hexprotect SLIM, Hexprotect MAX R
Moderate (40–75 MPH)
Open agricultural ponds, suburban reservoirs
High (75–130+ MPH)
Coastal, desert, high-plains, hurricane zones
3 Potable Water / Food-Grade Requirements
If the cover will contact drinking water, food-process water, or any liquid requiring NSF/ANSI or FDA material certification, your options narrow significantly.
- NSF/ANSI certification needed — Hexprotect AQUA is available in food-grade HDPE that meets NSF/ANSI and FDA requirements.
- Standard industrial applications — Any product in the AWTT range can be used. All are manufactured from UV-stabilized HDPE.
4 Insulation Requirements
If you need to retain heat (digesters, heated process tanks, aquaculture), the R-value of the cover becomes a primary selection driver.
No insulation needed
Moderate (R-2 to R-4)
Hexprotect AQUA (R-2), Rhombo Hexoshield (R-4)
High (R-8)
Maximum (R-17+)
5 Budget
All AWTT floating covers deliver a strong ROI through water savings, chemical reduction, and energy conservation. But if budget is your binding constraint, here is how the range stacks up.
- Lowest cost per sq ft — Armor Ball (for sheltered sites with no wind resistance requirement).
- Best value wind-resistant option — Hexprotect AQUA offers 99% coverage and 130 MPH wind resistance at a competitive price point.
- Premium performance — Rhombo Hexoshield or Rhombo 189 for sites where maximum evaporation reduction and insulation justify the investment.
Product Decision Matrix
Side-by-side comparison of all AWTT modular floating cover products. Click any product name to view full specifications.
| Product | Coverage | Wind | R-Value | Evap Reduction | Best For |
|---|---|---|---|---|---|
| Armor Ball® | 91% | 35 MPH | R-2 | Up to 90% | Budget applications, sheltered ponds |
| Armor Ball® AQUA 275 | 91% | 75 MPH | R-2 | Up to 90% | Moderate-wind sites, cost-effective |
| Hexprotect® SLIM | 99% | 30 MPH | R-1 | Up to 95% | Sheltered high-coverage applications |
| Hexprotect® AQUA | 99% | 130+ MPH | R-2 | Up to 95% | Best all-around, potable water safe |
| Rhombo Hexoshield® 66 | 99% | 130 MPH | R-4 | Up to 98% | High buoyancy + R-4 insulation + extreme wind |
| Rhombo Hexoshield® 189 | 99% | 90+ MPH | R-8 | Up to 98% | High insulation + wind resistance |
| Hexprotect® MAX R | 99% | 40 MPH | R-17+ | Up to 98% | Maximum insulation, digesters |
Decision Flowchart
Start at the top and follow the arrows. In most cases, you will arrive at a single recommended product in three questions or fewer.
Do you need R-17+ insulation?
YES → Hexprotect MAX R
NO → Need R-8 + wind resistance? → Rhombo Hexoshield 189
Do you need 99% coverage?
YES → Hexprotect AQUA
NO → Need maximum evaporation reduction? → Rhombo Hexoshield
YES → Armor Ball
Do you need 99% coverage?
YES → Hexprotect SLIM or Hexprotect AQUA
NO → Armor Ball AQUA 275
Common Application Scenarios
Real-world project profiles and the AWTT product our engineering team recommends for each.
Municipal Drinking Water Reservoir in a Windy Area
A 5-acre potable water reservoir in the Texas panhandle experiences sustained winds of 60+ MPH with gusts exceeding 100 MPH during spring storm season. The utility needs NSF/ANSI-compliant contact materials and must prevent algae growth to reduce disinfection byproducts.
Why: NSF/ANSI food-grade HDPE, 99% coverage to block algae, and 130 MPH wind resistance handles the worst Texas storms.
Anaerobic Digester in Minnesota Winter
A municipal wastewater plant in Duluth, MN operates heated anaerobic digesters year-round. Winter air temperatures drop below -30°F, and the facility is losing significant heat through the digester liquid surface, driving up natural gas costs.
Why: R-17+ thermal insulation drastically reduces heat loss. The digester is enclosed, so wind resistance is not a primary concern.
Large Mining Evaporation Pond in Nevada
A gold mining operation near Elko, NV has a 20-acre process water pond. Evaporation losses exceed 6 feet per year and represent the single largest operational water cost. The site is exposed to high desert winds.
Why: 98% evaporation reduction (the highest in the AWTT range) combined with 130+ MPH wind resistance for exposed desert conditions.
Small Wastewater Lagoon on a Tight Budget
A small rural wastewater district in Oklahoma needs to reduce evaporation from a 0.5-acre facultative lagoon. The lagoon is surrounded by trees and berms, effectively shielding it from wind. Budget is the primary constraint.
Why: Lowest cost per square foot in the AWTT range. Sheltered site means wind resistance is not required, making Armor Ball the ideal value pick.
Airport Deicing Pond with FAA Compliance
A regional airport in the Pacific Northwest must manage a 2-acre glycol recovery pond. FAA regulations require wildlife deterrence to minimize bird strike risk near runways. The pond also produces odors that affect terminal buildings.
Why: 99% coverage provides an effective wildlife (bird) deterrent while also containing VOC odors. Wind resistance handles Pacific Northwest storm exposure.
Still Not Sure Which Cover Is Right?
Try our interactive Product Selector Wizard to get a personalized recommendation in under 60 seconds, or contact our engineering team for a free consultation.