Measuring water content in Rockwool

[colordude]

Is anyone using the Smartbee or Growtronix equipment to measure water content in their medium?
If so, how do you like it and would you recommend it?
I'm growing in Rockwool, pump didn't run for 24 hours, so lost 90% of crop. Currently have no way to warn of failure.

 

[vostok]

Measuring water content in Rockwool? = Weigh it