No, soil is not to be added to to the glass tubes of the hydroponic planters. The cuttings grow their roots in the water and continue to grow.
Yes, it is. Put the plant cuttings in the tubes with their aerial roots (at nodes) dipped in water. The nodes present in water will grow more roots.
To start with you can put cuttings of money plant (pothos), philodendrons, syngoniums, Monstera Adansonii, Spider plant babies, Wandering Jew or any other creeping vines.
When the water in the glass tubes comes down to 1/3 of the tube, its time to water the plants again. Generally you need to water once in 10 days.
These planters can be put up next to a window in your bedroom , living room or even kitchen. Set up your workspace, study space, entryway, balconies, porches etc with these hydroponic planters.