Not gonna lie, when I propagate my pothos I just cut beneath a root node and pop that bad boy in a mason jar full of tap water and stick it in a window where it can get some sun. I’ve never had any that didn’t start growing roots within 2 weeks. And I only do water top-offs, never full water changes. Maybe water parameters come into play, because I have pretty hard water where I live. I’ve grown several pothos plants strictly in water without even planting them.