always better to be safe than sorry.I would start off with 1/4 stregth and watch them.If the growth is slow or leaves start to yellow add more nutes.If i might make a suggestion go and buy an ec meter.With an ec meter you will be able to see how much nutes your plants are taking up.if ec climbs too much nutrients.If the ec drops not enough nutes.if the ec stays pretty steady, equalibrium(perfect)