The Complete Guide to Arena Sand Selection

Sand is not a generic commodity. It is an engineered material defined by four measurable properties, and every one of them affects how your footing rides, drains, compacts, and holds up over time.

Particle size distribution — measured through sieve analysis — describes how the sand is graded across a range of sizes. A sand can be uniformly sized (most particles are roughly the same), broadly graded (a wide spread of sizes), or somewhere in between. Each pattern creates a different riding experience.

Uniformly sized sands resist compaction because particles of the same size don't nest tightly together. But they also tend to feel loose and deep because there's nothing filling the gaps between grains. Broadly graded sands with a wide size range develop high shear strength because smaller particles fill the spaces between larger ones — but if taken too far, they compact into hard, concrete-like surfaces with poor drainage.

The Racing Surfaces Testing Laboratory's Arena Bulletin No. 1, authored by Prof. Mick Peterson, Katrina Stavermann, and Dr. Lars Hernlund, describes this as the fundamental trade-off in sand selection. Most successful arena sands show one or two peaks of mass retained across the US sieve series, with the #60 and #100 mesh fractions doing much of the structural work. The bulletin recommends using fiber additives to gain shear strength without relying on excessive fines — a principle that directly informs how Performance Footing designs footing systems.

Particle shape is arguably the most underappreciated variable in sand selection — and the one most often ignored by quarries.

Sand particles exist on a spectrum from rounded to angular. Rounded particles, common in river deposits and naturally weathered alluvial sources, are smooth and polished. They roll against each other rather than interlocking. The result is footing that feels loose, shifts under hoof, and never truly stabilizes regardless of how it's graded.

Angular particles, typically produced by mechanical crushing, have sharp edges that lock together tightly. Too angular, however, and the sand compacts aggressively, resists grooming, and can abrade hooves over time.

Sub-angular sand — with moderate edge definition and some surface texture — is the practical target for arena footing. It provides enough interlock to stabilize without compacting into a hard surface. Both the FEI Equestrian Surfaces guide and Penn State Extension research reinforce this: rounded sands roll and destabilize; overly angular sands compact too hard; sub-angular sands are the working sweet spot.

The challenge is that particle shape rarely appears on a quarry's product sheet. A sieve report tells you nothing about whether the particles are round or angular. Two sands with identical gradation curves can perform completely differently in an arena because one is rounded river sand and the other is sub-angular manufactured sand. This is one of the primary reasons sieve analysis alone is not sufficient for making a sand purchasing decision.

Not all sand is made of the same mineral. Quartz and silica sands are the hardest and most durable — they resist breakdown under repeated hoof traffic and grooming. Limestone-based sands are softer and will degrade over time, producing fines that increase dust, promote compaction, and change the riding surface characteristics.

ASTM F3419 provides a standardized X-ray diffraction (XRD) method for identifying mineral composition of equine surface materials. For arena footing, the general target is greater than 90% hard silica or quartz content. Sands with significant carbonate, feldspar, or soft mineral fractions will break down faster, generate more dust, and require more frequent replacement or remediation.

Mohs hardness, the standard scale for mineral durability, rates quartz at 7 out of 10. Limestone sits around 3 to 4. That difference is not academic — it determines whether your sand will hold its gradation for years or slowly grind itself into dust.

Fines — particles smaller than 0.075 mm (passing the #200 sieve) — are the single biggest driver of dust and compaction problems in arena footing. Clay and silt particles fill pore spaces between sand grains, reduce drainage, increase compaction under traffic, and become airborne when the surface dries.

ASTM C136 establishes the standard sieve-analysis procedure, but it explicitly notes that the fraction finer than 75 μm should be verified using ASTM C117 — a wash procedure — because dry sieving alone does not adequately measure true fines content. Fine clay and silt particles cling to larger grains and pass through dry screening undetected. This means a standard dry sieve report can significantly understate the actual fines in your sand.

For arena footing, fines passing the #200 sieve should generally stay below 3–5% depending on discipline. Particles smaller than 0.053 mm should approach zero. These are the particles that cause respiratory issues for horses and riders, create dust clouds during dry conditions, and drive the progressive compaction that turns footing hard and unrideable over time.

There is no ASTM specification for "equestrian sand." The term has no industry-standard definition, no governing body, and no certification process. When a quarry labels a product EQ100, EQ70, or "Equestrian Blend," that is a marketing designation, not an engineering specification.

In most cases, the EQ prefix simply indicates that the sand passes a particular sieve — EQ100 means it passes a #100 mesh screen. That tells you something about maximum particle size. It tells you almost nothing about gradation distribution, particle shape, mineral hardness, fines content, or capillary behavior — the properties that actually determine whether the sand will work in an arena.

This is not a criticism of quarries. Sand production is their business, and they're very good at it. But sand production and footing design are different disciplines. Most quarries do not have expertise in equine biomechanics, discipline-specific shear requirements, or the long-term behavior of granular materials under repeated hoof loading. Expecting a quarry to design your footing is like expecting a lumber yard to design your house — they can supply excellent material, but the engineering has to come from somewhere else.

Arena owners often make purchasing decisions based on a sieve report provided by the quarry or sand supplier. In many cases, that report is the only technical data they have. The problem is that sieve reports have several significant limitations that most buyers are never told about.

The report may not be current. Quarries mine from natural deposits that are not uniform. A vein of sand that tested well eighteen months ago may have shifted in character as the quarry moved into a different section of the deposit. Unless the report is dated from a recent production lot — ideally the lot you're actually purchasing — it is historical data, not a guarantee of what's being loaded onto your truck.

Lot-to-lot variability is real. Even within the same quarry and the same product line, sand characteristics can drift meaningfully from one production run to the next. Natural deposits are geological formations, not manufactured products. Research on arena sand specification recommends holding lot-to-lot drift to roughly ±5 percentage points on the #16 to #30 sieves, ±4 on the #50 to #100 range, and ±1 on the #200 sieve. Those are tight tolerances, and most quarries do not monitor or guarantee that level of consistency for their equestrian products.

Dry sieving understates fines. ASTM's own sieve analysis standard recognizes that dry sieving does not adequately capture the true fines content of a sand. The C117 wash procedure is required for accurate fines measurement — but most quarry-provided sieve reports are based on dry analysis only. This means the sieve report may show 2% passing the #200 sieve when the actual washed fines content is 4% or more.

Particle shape is missing. Standard sieve analysis measures particle size. It does not measure particle shape. Two sands with identical sieve curves can produce completely different riding surfaces if one is rounded and the other is sub-angular.

What you ordered may not be what you received. Without independent analysis of the sand that was actually delivered and installed, you have no way to verify that what's in your arena matches what's on the spec sheet.

A proper sand analysis goes beyond what a quarry sieve report provides. It answers the question that actually matters: will this specific sand, from this specific source, create a stable and rideable surface for the specific discipline and conditions in this specific arena?

What a complete analysis covers

A thorough sand evaluation should assess five parameters:

• Sieve analysis (ASTM C136/C117) — the full particle size distribution across the standard sieve series, including a washed fines determination per C117.
• Particle shape assessment — a visual or microscopic evaluation of angularity. The ideal classification for arena sand is sub-angular.
• Mineralogy (ASTM F3419) — X-ray diffraction to confirm mineral composition. The target is ≥90% quartz or hard silica.
• Organic content and pH — organic content should be below 2%, and pH should fall in the 6.5–7.5 range.
• Moisture behavior — how the sand holds and releases water. This directly affects dust generation, surface cohesion, and the effectiveness of liquid maintenance products.

When to analyze

Sand analysis should happen at three critical points:

• Before purchasing. Evaluate the candidate source against your discipline and climate requirements before committing to a large-volume order.
• After delivery. Verify that the sand that arrived matches the sand that was specified. Pull samples from multiple locations and test them independently.
• After installation and use. Sand characteristics change over time as particles abrade, fines accumulate, and organic material builds up. Periodic re-analysis helps identify when maintenance or amendment adjustments are needed.

There is no single "best" arena sand that works everywhere. The sand available in any given region is determined by local geology, and geology varies dramatically across the country and around the world.

How geology creates different sands

Quarries don't manufacture sand — they extract it from natural deposits formed by millions of years of geological processes. Glacial deposits in the northern United States tend to produce sands with a mix of mineral types. River and alluvial deposits are often rounded and polished because water transport tumbles particles over time — these are among the most common sources of problematic arena sand. Decomposed granite deposits in the western states can produce angular material that compacts heavily. Coastal deposits may be contaminated with shell fragments (calcium carbonate) that break down under traffic.

Matching sand to climate

The same sand behaves differently in different climates. An outdoor arena in the arid Southwest faces rapid moisture loss, intense UV exposure, and extreme surface temperatures. The same sand in the Pacific Northwest deals with persistent moisture, slow evaporation, and seasonal freeze risk. A sand that drains adequately in a dry climate may drain too fast in a region where the goal is moisture retention.

Performance Footing's approach accounts for climate as a core design variable, not an afterthought. Indoor arenas in dry climates need sands and additives that retain moisture. Outdoor arenas in wet climates need coarser, more drainage-friendly gradations. Freeze-thaw regions need materials that don't lock solid in winter.

Different disciplines place fundamentally different biomechanical demands on the footing surface. A sand that's ideal for dressage may be completely wrong for reining, and vice versa.

Sand selection is the foundation. But sand alone has inherent limitations that no amount of careful sourcing can eliminate. Even perfectly selected, well-graded, sub-angular sand will compact under repeated traffic, lose moisture between waterings, develop inconsistencies across zones, and generate dust as particles abrade.

This is where FIBR, FLEX, and LOCK enter the system — not as fixes for bad sand, but as precision tools that extend the performance capabilities of good sand.

The approach: Analyze, Select, Enhance, Tune

Performance Footing's process begins with understanding the sand — what's available regionally, how it tests against the requirements of the specific discipline and climate, and where its natural properties fall on the spectrum from ideal to needs-work.

Why modularity matters

FIBR, FLEX, and LOCK are deliberately designed as separate, modular products rather than a single premixed blend. A private dressage rider in the Pacific Northwest working with a fine, well-graded local sand and dealing with year-round moisture needs a completely different additive approach than a busy hunter/jumper training barn in central Texas working with a coarser sand and fighting dust and heat. Separate modules mean each arena gets exactly the combination and rate it needs.

Whether you're building a new arena or troubleshooting an existing one, these are the key indicators to assess when evaluating sand.

The recommendations in this guide are built on the most current peer-reviewed research and industry standards available for equestrian surfaces.

• The FEI Equine Surfaces White Paper (2014) and Equestrian Surfaces: A Guide represent a four-year collaboration among eight experts from six universities, three research centers, and two welfare charities. A key finding: unexpected variations within otherwise excellent footing were more damaging to horse soundness than consistently poor footing — uniformity matters more than perfection.
• ASTM F3400 provides the in-situ testing standard for functional properties of equine surfaces using the Orono Biomechanical Surface Tester (OBST), developed by Prof. Mick Peterson at the University of Maine and now used for HISA pre-meet inspections in US racing and FEI Championship arena testing.
• ASTM F3415 addresses triaxial shear strength and cohesion. ASTM F3419 provides the XRD mineralogy standard. ASTM C136/C117 establish the sieve analysis and washed fines procedures referenced throughout this guide.
• The Racing Surfaces Testing Laboratory's Arena Bulletin No. 1 is the most footing-specific published sand specification guide currently available, addressing gradation, shape, and the relationship between sand properties and surface behavior.
• Penn State Extension and University of Kentucky Extension publications provide practical, research-backed guidance on material selection, maintenance, watering, and the biomechanical demands of different disciplines.
• USEF Rule GR8.5 mandates that footing in all competition areas must be safe, consistent, and appropriate for the intended use — a regulatory requirement that reinforces the need for deliberate footing design rather than ad hoc sand purchasing.

If you're building a new arena, the sand decision should happen before anything else — before base construction, before additive selection, before equipment purchasing. Understanding what's available in your region, how it tests against the requirements of your discipline, and where it needs enhancement is the single highest-leverage step in the entire project.

If you're troubleshooting an existing arena, the first step is finding out what you're actually riding on. Request a current sieve report from your sand supplier — or better, pull samples from your installed surface and have them independently analyzed. You may discover that the sand you thought you had is not the sand that's in your arena, or that the sand has changed character over years of use, traffic, and organic accumulation.

Performance Footing offers sand evaluation guidance and can help you determine whether your current sand is a suitable foundation for FIBR, FLEX, and LOCK — or whether the sand itself needs to change before any additive investment makes sense. We would rather have that honest conversation upfront than sell you a product that can't do its job because the sand underneath it won't support it.

Your arena is only as good as the sand it's built on. Everything else — every product, every drag, every watering schedule — follows from there.