Cameron, I am certainly no expert here, only growing adenium from seed for 3 yr. When I transplant my seedlings into their own pot, usually a 3" pot, I mix in a few pellets of Osmacote into that media. In a few months, they'll go into a 6" pot and I will sprinkle Osmacote over the soil, probably about 1 level tsp. If I were to use water-soluble fertilizer, and there's no problem doing so, I would use a general purpose one and use it diluted at 1/2 the recommended dilution. I like the idea of fertilizing at low-dose every time I water or it rains. So far, this has worked for me.
