I trim mine every winter..well summer augish.seems it gets too leggy for me.When moved mine indoors(of course not where I wanted it) it did get some yellowishness on backside and dropped a few.I have some of the cuttings off it from august(what didn't trade off)and those are on screened porch.one in a pot
growing up bamboo piece and the other in hanging basket.I may not have shock issues cause of superthrive.its that B1 it does wonderes for
plants.whenever I transplant or something looks shabby I water in a dose.My walmart use to carry superthrive.Now I have to shop it online.
as to the black.I've not known of pothos to do that.MIL would know better.Thats her #1
plant to have& grow.may set your water out overnight may have a higher chlorine content.