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 NSF/ANSI 61 certified, FDA-compliant food-grade HDPE resin.
- 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. AWTT publishes its price tranches: non-insulated covers (Hexprotect AQUA, Armor Ball, Armor Ball AQUA 275) run $1.75–$2.50 per sq ft, medium-insulated Rhombo Hexoshield $2.50–$3.30, and the insulated MAX R $5.00–$7.00 — within each band, the low figure applies at 100,000 sq ft and above. 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-1 | Up to 90% | Budget applications, sheltered ponds |
| Armor Ball® AQUA 275 | 91% | 75 MPH | R-1 | Up to 90% | Wind-exposed sites, cost-effective |
| Hexprotect® SLIM | 99% | 30 MPH | R-1 | Up to 95% | Sheltered high-coverage applications |
| Hexprotect® AQUA | 99% | 130+ MPH | R-1 | 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 97% | 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
Selection Cases from Real Projects
Anonymized selection cases drawn from AWTT's project and sales records — the situations that actually decide which product ships.
Coarse-Bubble Aeration Changed the Product — Petroleum Pond, Alaska (2026)
A petroleum facility in Alaska evaluated covering a roughly 9,000 sq ft (~840 m²) aerated treatment pond. The deciding factor was not wind or budget but the aeration system: coarse-bubble diffusers push hexagonal tiles apart directly above each diffuser, opening gaps in coverage, while fine-bubble aeration leaves the cover undisturbed. The distinction only shows up in operation — which is why AWTT asks about aeration type before quoting.
Why: Rhombo handles coarse-bubble turbulence better than flat hexagonal tiles. On coarse-bubble systems AWTT specifies Rhombo or adds extra coverage above the diffusers; fine-bubble ponds can run any product in the range.
The Indoor-Only Tile Specified Outdoors — Municipal Tender, Australia (2026)
A municipal water tender in Australia specified a low-profile hexagonal tile for an outdoor reservoir. AWTT engineering flagged the mismatch and the selection rule behind it: Hexprotect SLIM is ideal for indoor tanks where wind is not present — in any outdoor wind it will stack. The specification was revised to the water-ballasted tile.
Why: The SLIM rule is binary: indoors or fully sheltered only. Any real wind exposure requires ballast — Hexprotect AQUA carries a 130+ MPH rating and has come through four named hurricanes (Florence 2018, Dorian 2019, Nicole 2022, Helene 2024) with zero repairs.
The Balls-vs-Tiles Budget Flip-Flop — a Recurring Pattern (2023–2026)
The most common selection detour in AWTT sales files: a buyer arrives asking for "shade balls" on the assumption that spheres are the budget option, flips back to balls each time price pressure rises, and only settles after both geometries are quoted for the same square footage. The comparison quote usually ends the debate — the hexagonal tile delivers 99% coverage against 91% for balls, in the same published price tranche, and often at a lower quoted rate.
Why: More coverage per dollar is why the tile is the default recommendation on AWTT quotes. Balls stay on the table for sheltered ponds, moving equipment, and bird-deterrence work.
Replacing a Competitor Cover That Failed in Wind
A lagoon operator’s existing modular cover from another supplier accumulated on one side of the lagoon in wind, leaving the surface exposed — the classic failure mode of unballasted or under-ballasted covers. AWTT replaced it with the factory-ballasted hexagonal tile, which floats partially submerged so wind cannot get underneath it.
Why: Pre-loaded water ballast (100%–300% of dry tile weight) plus interlocking geometry is what keeps coverage in place. Above the rating, tiles may temporarily stack and then reform — any blown-out pieces go back in at a cost of cents each.
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.