Acclima TDR-310W

Proper placement of the Acclima TDR-310W substrate probe ensures accurate and consistent measurements of moisture, EC, and temperature, helping you optimise your grow conditions.

Rockwool cubes and slabs

For accurate readings, place the probe at the following positions:

• 4” x 4” x 4” cubes → 1 inch above the base

• 6” x 6” x 4” cubes → 1 inch above the base

• 6” x 6” x 6” cubes → 1 inch above the base

• 8” x 8” x 8” cubes → 2 inches above the base

• Rockwool slabs → 1 inch above the base in individual cubes

If using a rockwool slab, position the probe equidistant between two plants to capture the most representative root-zone conditions.

Coco coir and organic substrates

Probe placement depends on pot size for the most accurate root-zone readings:

• 1-gallon coco pots → 1 inch above the base

• 2-gallon coco pots → 2 inches above the base

• 3-gallon and larger coco pots → 3 inches above the base

Large no-till or living soil beds

Check out our FAQ for this specific use case below.

How do I position my substrate probe in a large no-till or living-soil bed?