Do you do your rooting inside or outside? I ask as I have repeatedly read that outside rooting is much better than indoors rooting.
I root them indoors where I can control the environment. I'm using a heat mat right now to keep them warm enough. And a humidity chamber to keep them from wilting.
how often you change out the water in the jar?
I replace the water and clean the jar about every 2 or 3 weeks depending on how clear the water looks to me.
Also what is the PH of your local tap water (your town web site should tell you)?
Last time I tested it, the tap water was ph8.8.
I too all of my zip lock bagged Psychotria leaf cuttings and replaced the paper towel a used the melted snow (PH 5.5) to wet the paper towel. The idea is to see if the cuttings respond to the lower PH which ought to suit them better than the filtered tap water I was using.
I root in ph7 distilled water. I've tried lower ph water to root the leaves and didn't think it worked as well for me. The lower ph does make a difference in the soil, however.
The wet paper towel method works very well it you want the leaves to root in multiple places.