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EuroCover Water Systems

Hexagonal floating cover vs. shade mesh — comparison

Floating covers block evaporation; shade mesh blocks sunlight only. Full comparison of evaporation, algae, lifecycle, cost, and use-cases.

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Hexagonal floating covers eliminate evaporation and algae; shade mesh blocks sunlight (suppressing algae) but is vapour-permeable, so it does NOT stop evaporation.

At a glance

Metric Hexagonal floating cover Shade mesh Notes
Evaporation reduction 90–97% 0–5% Mesh is vapour-permeable.
Algae suppression 95%+ 70–90% Both block sunlight.
Odor reduction 90%+ 0%
Lifecycle 25+ years 3–7 years
Capex / m² Higher upfront Lower upfront
Wind loading Self-ballasting, no anchors Requires anchor structure

Hexagonal floating covers eliminate evaporation and algae; shade mesh blocks sunlight (so it suppresses algae) but is vapour-permeable, so it does not stop evaporation. For most industrial water bodies, the difference matters.

Where each comes from

Shade mesh is a permeable woven fabric — typically HDPE or polypropylene — suspended above the water surface on an anchor frame. It blocks roughly 50–95% of incident sunlight depending on mesh density.

Hexagonal floating covers are solid modular HDPE elements that tessellate directly on the water surface, blocking sunlight AND removing the water-air interface.

When shade mesh is the appropriate choice

  • Algae suppression is the only goal
  • Evaporation reduction is not valued (heavily replenished water source, very low water cost)
  • 3–7 year lifecycle is acceptable
  • Small water body where anchor-frame economics work
  • Aquaculture applications where partial gas exchange is required

For these use cases, shade mesh is cheaper upfront.

When hexagonal covers are the appropriate choice

  • Evaporation reduction is valued (most industrial applications)
  • Odor or emission reduction is required
  • 25+ year lifecycle is the operating horizon
  • Anchorless deployment is required
  • Larger water bodies (mining, water utilities, irrigation, biogas)

Recommendation

For algae-only suppression on small specific applications, shade mesh works. For everything else, hexagonal covers deliver the bigger benefit envelope at lower 10-year total cost.

When Shade mesh makes sense

Shade mesh is appropriate where the only goal is algae suppression on a small water body, where evaporation reduction is not valued (e.g. heavily replenished water source, very low water cost), and where the 3–7 year lifecycle is acceptable. For most industrial applications, the lifecycle cost favours hexagonal covers.

Total cost of ownership over 10 years

Line itemHexagonal coverShade mesh
Capex (m²)Higher one-timeLower one-time
Replacement over 10 yearsNone1–2 replacements
Anchor / structure maintenanceNoneRequired
Water savings (10 years)Large positiveNegligible

Frequently asked questions

Does shade mesh reduce evaporation at all? #
Marginally — mesh is vapour-permeable. Some sources cite small (0–5%) evaporation reduction from reduced wind speed at the water surface, but mesh does not eliminate the water-air interface.
Is shade mesh cheaper? #
Per m² upfront, yes. Over the 25-year lifecycle of a hexagonal cover, shade mesh requires multiple replacements and delivers no water savings, so total cost favours hexagonal covers for industrial applications.
What about combining shade mesh with floating covers? #
Possible but uncommon. The hexagonal cover already blocks sunlight, so adding a shade mesh above offers no additional algae benefit. Where the operator wants UV protection for cover longevity, modern HDPE grades are already UV-stabilised for 25+ year exposure.
Is shade mesh useful for aquaculture? #
Yes — aquaculture is one of the cleaner shade mesh use cases because it suppresses algae while preserving gas exchange (oxygen) at the water surface. Floating covers in aquaculture require careful aeration design.
How does shade mesh handle wind? #
Shade mesh requires a tensioned anchor frame around the perimeter, typically posts and cabling. Wind loading on the mesh transfers to the frame; storm damage is a known failure mode. Floating hexagonal covers are self-ballasting and have no anchor frame.
Is shade mesh approved for potable water? #
Some HDPE shade mesh products carry NSF-61 certification, but the suspension framework above the reservoir introduces engineering and inspection requirements that don't apply to floating covers. Verify materials in contact with the regulator (DWI in UK, ARS in France, etc.).

Sources & further reading