Light Dependent Resistors (LDRs) are not inherently water-resistant, raising concerns about direct exposure to water, particularly regarding the insulation of wires. Placing an LDR inside a test tube can protect the wires while allowing the head to be exposed, although this may reduce light intensity. Test tube glass is generally effective at transmitting visible light, making it a viable option for experimentation. Users suggest that thin soda glass test tubes are affordable and worth testing for this application. The discussion centers on using an LDR in a pipe setup with LEDs, emphasizing the need for careful placement to maintain functionality.