Too much streching for 15th day of growth?

yes lower the lights, get them about 22 inches until flower, once flower starts you will want the light to be 14-16 inches, once those roots hit that water your plant will really take off, dwc is the way to go for sure, just remember to keep an eye on your ph every other day in the bucket, keep your ph about 6 for the whole time and you will have a great big harvest, for now though lower the lights