Substrate probes

What soil probes are compatible with the Grow Sensor?Which sensors should I purchase?What do the substrate probes measure?Can I change my substrate type in the Grow App?How do I connect a substrate probe to the Grow Sensor using the SDI-12 connector block?How many substrate probes can I use with the Grow Sensor?How do I position my soil probe for my pot size?My VWC reading is too low or high, help!