I only used rainwater with Canna nutrients, it was in the initial phase, there was nothing to complain about, only later the problems started, (B) (Mn) the second time I used rainwater only for seeds, the rest was tap water and there were practically no deficiencies but I focus on ecology, although better results are obtained with tap water, after a short thought I decided to use Biobizz starter fertilizers, see what will happen:)