If they're multi-growth plants, they should be blooming by now (approx. 16" leaf span = blooming size). Do you have a photo of the plants? We grow the adult plants and seedlings in fairly bright light (like 2,400 fc) and feed with a urea based fertilizer every second watering in Spring/Summer and every fourth watering in Fall/Winter. TDS of the fertilizer solution is approx. 150 ppm. Between fertilized irrigations we water with a blend of 90% R/O and 10% Lake Michigan water (Chicago).