Aqua Master Tools E300 Pro Substrate EC/Temp Meter

Check EC directly in the substrate — no runoff sample needed

Most EC meters are built to test liquid, which means testing your growing medium means squeezing out a runoff sample first and hoping it is representative of what the roots are actually sitting in. The E300 Pro is a substrate meter built to skip that step entirely: its probe is pushed straight into coco, rockwool or soil and gives an instant EC and temperature reading from the medium itself, which is a much more direct way to catch salt build-up or under/over-feeding before it shows up as a visible problem on the plant.

It is aimed at coco and rockwool growers running regular runoff-style checks who want faster, more direct readings without the mess of squeezing samples, and at anyone diagnosing a suspected nutrient lockout or salt build-up issue mid-grow. Like the rest of the Aqua Master Tools range it uses a replaceable electrode, so the part that takes the physical wear of repeated substrate insertion can be swapped out without buying a new meter, and the waterproof housing stands up to regular use around wet growing media.

• Direct substrate insertion — no runoff sample needed
• Measures EC and temperature together in one reading
• Replaceable electrode extends the working life of the meter
• Waterproof housing built for regular use around wet media
• Ideal for coco and rockwool growers checking for salt build-up