Begonia ‘Fireflush’ (Begonia rex hybrid)

I purchased this plant (smaller size) in late summer 2017. I potted it up in a clay pot (probably 4 or 5 inch version) using quite a concoction of planting medium (including vermiculite, perlite, sand, peat moss, and some orchid mix (small size), plus about 30% of a good house plant soil mix) ensuring primarily good drainage with some decent moisture retention. I keep this plant as a house plant only. It did not do much of anything that first autumn other than put up a couple of small shoots and they remained static until well into Spring. I keep this plant under artificial lights plus it was a few few back from a southeast facing window (covered in sheer curtains). Temps not below 60F and rarely reaching 83F or so in the summer. The plant remained somewhat 'static' until later in the summer of 2018 and then it literally took off. The intenseness of the red and the deep green make for an eye popping contrast. It is only my second begonia (the other is a Rex Jurassic Green). Not a difficult plant at all so long as the main requirements are met (moisture/drainage, filtered light, and temperature range). One other note, since I also raise carnivorous plants: I water using only distilled or R/O water (is this a requirement for these begonias? I don't have that answer). Enjoy this plant.