African Violet String?

I forgot what this system is called... wicking maybe. What kind of string should I use for the av pot that has a string in the bottom that goes into a supply of water?

I use nylon mason line because it does not break down or clog - I forget the other common name for it. I get the 3 ply but sometimes use it 1 or 2 ply, depending on the size of the pot. And yes, wicking is the term. There are few entries here: http://robsviolet.com/faq.htm