yup yup, tap water is not good because chlorine will burn them up...they're not used to it like humans are

also, the 1/2 tsp of nutrients you used was unnecessary...if you had soil with delayed release nutrients, then you probably won't need nutes until about time to start flowering...i've used some delayed-release nutrient soil for african violets, and the plants did just fine without any more food for the first 5 weeks

if you wanna use tap water, then bring it to a rapid boil on the stove and then let it sit and cool to room temperature...the chlorine will evaporate VERY quickly