Quick question about nutes?!

hi i am a newbie so im just wndering if my grow guide says my EC should be 1.5 and after ive added my nutes too my resovouir my reading is only 0.4 how do i raise the ec do i just keep adding more and more nutes? ive already added the recomended dose ? my water started of at a EC of 0.1

adding nutes will raise the EC but if your at the recamended level stay with that, no need to waaist nutes