The HM EC/TDS Hydrotester Pen provides a digital readout of the EC (Electrical Conductivity) and TDS (Total Dissolved Solids) in a nutrient solution. The EC refers to a substances ability to conduct electricity, whereas TDS is the combined total of any minerals, salts or metals dissolved in water or other liquids.

At Aqua Gardening, HM EC meters have proven themselves tough, waterproof and able to withstand drops. We've used the same EC pen for more than 3 years without an issue. The HM EC pens calibrate quickly, and automtically, with the EC 2.76 solution.


HM EC Meter Features

The HM EC pen measures EC, ppm and TDS, here are the detailed specifications:



 EC Range:  0 - 9990 uS  
 TDS Range:  0 - 8560 ppm (mg/L) 
 Temperature Range:  0 - 80 °C
 Resolution:  EC: 0.1uS   TDS: 01ppm   Temperature resolution is 0.1 °C 
 Accuracy:   +/- 2 %
 Calibration:   Digital by push button
 Probe:   Detachable, with platinum electrodes 
 Housing:   Waterproof (submersible)
 Power source:   3 x 1.5V button cell batteries (included) 
 Dimensions:   18.5 x 3.4 x 3.4 cm
 Weight:   90.7g

Made by HM: a trusted name in test and measurement.


To Prolong the Life of the EC Meter

Keep the metal probes clean. Consider getting probe cleaning solution and probe storage solution, this will make it last longer than using soapy water.

(SKU: 125038)

This calculator will show you the delivery charges for this product only.

Free Shipping Eligibility

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Delivery Information

  • Back Order products - These are products we usually carry in stock but are temporary out of stock. These products will be back in stock within a few days. We can send you an email notification when they are back in stock if you click on the “Notify me when back in stock” link. See the full details here.
  • Special Order products - These are products that we do not regularly stock. These products will be ordered specially for you, or dispatched directly to you from our supplier. See the full details here.
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1 Year (Replacement Warranty - Store warranty, this product needs to be returned to Aqua Gardening for testing and replacement. )


60 Day Returns - We will provide a refund, exchange or store credit where you have decided you no longer want the product and it is in new, unopened condition. More details.