What you need

Materials

  • Small rigid ring 4 to 8 inches in diameter, such as a metal coffee can with the bottom removed or a short section of PVC
  • Ruler marked in inches
  • Stopwatch or timer
  • Water container or hose with a gentle flow
  • Sand, plumber's putty, or non-marking clay to seal the ring edge
  • Notebook or phone for recording times

Step by step infiltration ring test

  1. Pick a representative spot away from edges, drains, or low points. Brush the turf fibers upright.
  2. Press the ring down into the turf surface. Create a tight seal around the outside of the ring with sand or putty so water does not leak under the edge.
  3. Pre-wet the area inside the ring with a small amount of water, then let it drain. This stabilizes the test.
  4. Add water to about 1.5 inches depth inside the ring. Use the ruler to mark your starting level.
  5. Start the timer and watch the water level drop. Record the time it takes for the level to drop exactly 1.0 inch. If the drop is slow, you can measure a 0.5 inch drop and convert.
  6. Repeat the test in two or three different locations and average your results.

Calculate your drainage rate

Convert the time per inch into inches per hour using this formula:

  • Inches per hour = 60 divided by minutes per inch
  • If you measured a 0.5 inch drop, first find minutes per inch = measured minutes divided by 0.5

Examples

  • 1.0 inch drop in 3 minutes: 60 ÷ 3 = 20 inches per hour
  • 0.5 inch drop in 2 minutes: minutes per inch = 2 ÷ 0.5 = 4. Rate = 60 ÷ 4 = 15 inches per hour

Converting to gpm per square yard

  • gpm per square yard = inches per hour × 0.0935
  • inches per hour = gpm per square yard ÷ 0.0935

This lets you compare your field measurements to manufacturer specs that are often given in gpm per square yard.

Interpreting results

  • Faster is better. The turf backing usually drains quickly. The base and subgrade are often the limiting factors.
  • Look for practical performance. During normal rain, you should not see standing water on the surface after the rain stops. Persistent puddles point to base, slope, or outlet issues.
  • Test several spots. Low areas, high-traffic lanes, and pet zones may show different rates.

Testing variations

Installed turf with infill

  • Groom with a stiff broom to open fibers.
  • Vacuum or blow off debris that might block pores.
  • Run the ring test as above. If results vary widely, add an extra test after grooming to see the impact.

Base-only test before install

  • Place the ring directly on the compacted base and seal the edge.
  • Run the test. This isolates base permeability before the turf goes down.

Areas with drainage layers

  • If you have shock pads or drainage grids, ensure the ring sits flat so water does not bypass through gaps.
  • Note that these layers can move water laterally. Repeat tests to confirm consistency.

Improve drainage if results are slow

  • Deep clean the surface. Remove debris, hair, and fines that clog pores. Power broom if needed.
  • Refresh or correct infill levels to manufacturer guidance. Overfilled or heavily compacted infill can impede flow.
  • Check seams and edges. Adhesive squeeze-out or poorly placed tape can block perforations.
  • Assess base and slope. Regrade low spots, add a more open-graded base layer, or add trench or French drains to carry water away.
  • Confirm outlets. Make sure water has a place to go and that catch basins or weep holes are clear.

Accuracy and quality tips

  • Seal the ring well. Bypass flow under the ring will distort results.
  • Keep the pour gentle to avoid scouring infill.
  • Use the same depth and method for each test to keep results comparable.
  • Record temperature and recent weather. Very dry bases may absorb differently on the first run.
  • Average three tests for a reliable number.

When to call a pro

If you see persistent ponding, slope conflicts, or highly variable test results, ask a certified installer to run a professional infiltration test and evaluate the base and drainage plan. FusionTurf pros can measure accurately, pinpoint bottlenecks, and recommend a fix that keeps your surface playable, clean, and ready for weather.