A slurry test measures root-zone pH and EC from a sample of the medium itself. In the common 1:2 dilution method, one volume of moist medium is mixed with two volumes of distilled water, left for about 30 minutes, and the liquid measured. Readings depend on the method, so compare like with like (Michigan State University Extension).
In practice
Use a slurry test when runoff is hard to collect, in living soil, or to check a bag of medium before planting. Take samples from the root zone, not the surface. The 1:2 method gives lower EC numbers than pour-through, so interpret each against its own reference ranges.being reviewed
Don't confuse with
- Pour-through: measures the liquid pushed out of the pot by added water.
- Runoff testing: measures whatever drains after a normal watering, a rougher estimate.
pH measures how acidic or alkaline a solution is on a 0–14 scale; in growing it controls nutrient uptake, with soil best near 6.0–7.0 and hydro 5.5–6.5.EC (electrical conductivity) measures how well a solution conducts electricity, a proxy for total dissolved salts; growers read it in mS/cm to gauge nutrient strength.Runoff is the water or nutrient solution that drains out of the bottom of a container after irrigation; growers test it to see what is happening in the root zone.Living soil is an organic growing medium managed to sustain an active soil food web, so microbes and invertebrates release nutrients and the soil is reused across cycles.The root zone is the volume of medium or solution where a plant's roots live, including its water, air, temperature, pH, EC and microbes.A standard way to sample root-zone pH and EC: water the pot to saturation, wait 30 minutes to 2 hours, then pour a set volume of distilled water on top and measure the first liquid that drains out.Runoff EC is the conductivity of solution draining from the pot; compared with input EC, it shows whether salts are building up or being used up in the root zone.A pH meter measures solution pH with a glass electrode whose voltage changes with hydrogen ion activity; it needs regular calibration and a moist probe.An EC meter measures how well a solution conducts electricity, giving nutrient strength in mS/cm or as ppm via a conversion factor.
