<span class="link_user">@Bigdjm88</span>, Rinsing out Coco with plain water is not a good idea, it messes up coco's Cation Exchange Capacity. Well at this point, if the growth has stopped then there is not much to lose. If I were you I would either transplant into soil and keep using Biobizz(it works wonders in soil) or I would get Coco specific mineral nutrients.
