is it just a vase filled with water?

My mother has a couple that look like that but in blue,she uses them only for rooting and has very good luck with them. She claims she only uses water.

a "lucky" vase then?

water and when the rooting starts a drop or two of plant food mix every couple weeks. normally i move them on earlier but this one stayed because its such a slow grower i wasn't sure what was going on.