I have not had an opportunity to set up an AP system yet, but am growing some avocados from seed and propagating some confederate jasmine in my window. Anyway, I just purchased this:

https://www.amazon.com/gp/product/B01GDT048Y/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

I will let you know how it goes.