I have a question for the community. I've been using a double prong meter (left side of picture) for years. I never used it to determine the pH or sunlight. I only used it for soil moisture. For whatever reason, I decided to buy a new meter, a single prong (right side of picture) to measure only soil moisture. The single prong always gives me a high moisture reading indicating I don't need to water the plant. This is an unusual reading for me. I decided to double-check this reading with the two prong & I get a reading of zero moisture. Which one is right?