Mild warm, soapy water to clean the line. I stretch it at the beginning of each fishing trip. Pull 6 feet of line off at a time, stretch it tight, using steady pressure, never a sharp jerk. I do this for the entire line, even if I'm fishing small waters. Depending on the line, sometimes when I clean & dry it, I'll rub some line dressing on it to help keep it's floatability.