In my indoor plant room in Minnesota where I have pretty good control of temperatures, I am growing a kovachii itself and I am successfully growing and blooming kovachii hybrids Fritz Schomburg, Yoko W. Fischer, and Robert-Jan Quene. They are all in straight Hydroton. They get fertigated from the top on a frequency that varies with the season but the top layer of LECA is heavily misted with RO water almost every day. With a testing pot I have seen that the media remains damp, but not wet. If I were out of town very much I wouldn't choose this method. I was successful with LECA plus about 25% rock wool and watering every 5-7 days but you have to accept cyanobacteria growing on the surface rock wool.