Cleaning tubing

[Eliemma]

Wonder what is the best for cleaning tubing. I am using 3/16 but am wondering what is the best for cleaning tubing and removing slung. Hydrogen peroxide or a bleach based cleaner?

[buckeye gold]

I used hydrogen Peroxide in my 3/16th, but I done it right after I quit for the season. I walked lines a few days ago and saw very few black spots and those were in drops. I would think if you've let lines sit and dry then you have a lot harder task on hand.