first timer dwc

gonna change the water and add som jungle juice it says 396ml per 100 litre i just want to make sure my math is right i have 13 ls so 51 ml anyone plz they have been through enough first 2 weeks light was5t away and they just got some miracle grow for a week,here they are anyways some help would be nice thanksView attachment 1939120View attachment 1939121View attachment 1939122View attachment 1939123View attachment 1939124

anyone plz!!!!

What I came up with is the same as you for dosage. Take the 396mL / by 100L (recommended dose)= 3.96mL per L x 13L= 51.48mL. Start off with a little less to see how plants respond to nute change imo. Ph test water ect, ect. But I'm sure you know that.