I’m not sure if this is the right place for the question, but I’ll ask it anyway. Does anyone know if there’s a place in the US that sells the C&G wicks? I need to replace mine (they’re root-infested) and the int’l shipping is a bit high. $10 shipping for $2 of wicks. 
Click & Grow has them in stock. They are the only ones to carry them. But you can use cotton cording. One grower has shown photos using this. And I used a piece of wool felt in one of mine that dried up until I could get the replacement wicks. Didn’t take a photo but it worked fine. I tried a knot in one end and threaded it through the tube, had about 2" hanging out.