The perfect and even moisture level and Drainage capabilities are the key to a perfect Arena Surface – think of what it’s like riding on the Beach at Low Tide!

A perfect arena surface depends on even moisture and effective drainage—similar to the ideal footing found on a beach at low tide.

Sub-surface irrigation systems provide far greater efficiency and sustainability than overhead sprinklers, while also improving drainage during rainfall. As installers of both the HIT ActiveAqua and Ebb-and-Flow systems, we help clients understand the technical differences, benefits, and limitations of each. Although both systems perform well in indoor and outdoor arenas, the best choice depends on climate and regional conditions.

Construction and Configuration

Here, let’s examine the construction processes of each system that we offer.

HIT Active Aqua UnderGround Watering System for Horse Arenas

A graphic illustrating the layers of the HIT Active Aqua underground watering system.

Graphic by Jelka UK

  1. The fence posts with kickboards are installed.
  2. Sub-base: A free draining base with 4-5″ of a clean 3/4 DrainRock sloped @ 1% longitudinally. No pumps are needed to remove excess rainwater.
  3. Base: A special permeable liner covers the rocks followed by HIT DrainGrids as the PERMANENT separation layer between the rocks and the arena footing. Rocks or the liner will never migrate into the arena surface.
  4. Arena footing: A fine sand is being installed above the DrainGrids 4-6 inches depending on the discipline. Can be constructed with sand only or a sand and fiber surface.

Ebb- and Flow Horse Arena System

A graphic illustrating the layers of the Ebb and Flow watering system.

Graphic by Jelka UK

  1. Cut and fill of the natural ground laser at 0% plane.
  2. Install fence posts with a concrete curb or kickboards.
  3. Lay down 2″ coarse sand.
  4. Roll out a heavy laminated PVC waterproof liner to contain the water.
  5. Lay the drainage pipes covered with landscape fabric.
  6. Apply of a coarse sand 7 inches.
  7. Apply of the footing sand 7 inches.
  8. Install water level control tanks/shafts  for the pump-system to maintain the perfect moisture and drainage content

Water consumption

The capillary action of the silica sand is moving the water in the upward direction and absorbs the moisture  like a sponge.
The HIT system uses 50% less water than the Ebb- and Flow system as only  6-7 inches sand versus 13 inches of sand are being watered.

Air flow in the sand

The HIT system is laid on a slow percolating liner, which still allows rain water to percolate through BUT also keeps the sand BREATHING. The sand never accumulates any algae, bacteria or fungi. The Ebb-and Flow system creates algae on the surface and mold, bacteria and fungi in the lower part of the sand which sits on a non-permeable liner.

Drainage HIT System compared to Ebb- and Flow System

While the Ebb-and-Flow system relies on drainage pipes connected to a limited number of control shafts—and on pump capacity to actively remove rainwater—the HIT System delivers significantly higher drainage capacity by functioning as a fully free-draining base system.

Rainwater moves immediately and naturally through the arena footing and into the DrainRock layer below, without dependence on drainage pipes and pump speed.  A permanent separation layer between the DrainRock and the arena footing ensures that drainage efficiency remains uncompromised over time, while completely preventing any migration of DrainRock or non-woven geotextile material into the riding surface.

The Ebb-and-Flow system is known to experience drainage challenges when only fine sand is used, rather than a two-layer coarse/fine sand profile. Over time, the fine sand in the lower layer can become over-compacted, reducing permeability and progressively clogging the drainage pipes, which significantly slows overall drainage performance.

Restoring proper drainage in these situations is extremely difficult, as access to the compacted lower sand layer typically requires disturbing or destroying the embedded pipes and liner system, making remediation both invasive and costly.

Even Moisture

In partially shaded or covered arenas, maintaining consistent moisture levels can be challenging. One side of the arena is often exposed to direct sunlight while the opposite side remains in shade, leading to uneven moisture. Similarly, during rainfall, the windward side of the arena can receive significantly more moisture than the rest of the surface.

These variations can be effectively addressed with the HIT System, which allows for 4–5 independent watering cycles that can be programmed with different settings. This level of control enables precise moisture management across the arena, ensuring a consistently uniform riding surface regardless of sun exposure, shade, or wind-driven rainfall.

Irrigation controller

At Footing Solutions USA, we work with Galcon GSI Irrigation, a cellular, web-based controller that allows clients to monitor water consumption for their HIT ActiveAqua system in real time via the Galcon App.

Replacing of Arena Footing

When your arena footing reaches the end of its lifespan or becomes over-compacted, replacing it with new sand and additives is simple with the HIT System. The old surface can be easily removed off the HIT-DrainGrids—the permanent separation layer between the sub-base and arena footing—allowing for straightforward installation of fresh footing without disturbing the underlying watering and drainage system.

Mineral build up and maintenance of the Ebb- and Flow System

In order to prevent the water in the system from accumulating bacteria, mold, germs and other contamination, we recommend replacing the entire system with water on a regular basis. One or two times a year, preferably in summer, the entire system should be pumped out and refilled with the heavy rain function. This also reduces the formation of odor emissions in the summer months. Because water is a regional element, it can contain different and regionally accumulated minerals.
Lime, iron and other mineral substances can cause discoloration of the sand and deposits in the system. The pumps and sensors in the system are particularly susceptible to these deposits. Cleaning should be done where these minerals are abundant regularly. A failure of the devices or a replacement of these devices due to wear and tear can occur in the long term.
So, the Ebb- and Flow System is more suitable in high precipitation climates where the rainwater which is pumped out constantly is cleaning the sand.

Summary

FeatureEbb-and-FlowHIT ActiveAqua
Drainage efficiencyModerate, dependent on pipe and pump speed; prone to cloggingHigh, natural free-draining base; permanent separation layer prevents migration
Moisture consistencyLimited, uneven in sun/shade/windExcellent, 4–5+ programmable watering cycles, zone-specific control
Water usage (30,000 sq. ft.)~4,000 gallons~2,000 gallons
Footing replacementDifficult, pipes at riskEasy, footing removed off DrainGrid layer without disturbing base
Long-term maintenanceComplex and costlySimple and low-maintenance
Monitoring & controlIrrigation Computer is limitedRemote via Galcon GSI cellular App
A comparative chart between the HIT Active Aqua and Ebb-and Flow systems

About Hilo Nick

Hilo is a lifelong equestrian, having competed in jumping and dressage in Germany as well as in the US. As a compassionate rider, Hilo understands the biomechanics of the horse and has deep-seated expertise and a gifted feel for sand—the most important aspect in any footing. Because of this, Hilo hand-picks the sand for all of her FootingSolutionsUSA clients. “I LOVE sand,” she says. “You have to have the right feeling for good sand and combine it with the technical and engineering aspects. I never stop searching for even better sand blends and geotextile additives to provide friendly footing for the horses.”Hilo founded FootingSolutionsUSA in 2004 to fill a void in quality riding surfaces in the US, which at the time were behind in comparison to European riding arenas.

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