help me please

i have had these skunk no.1 clones for 6 days i though i nute burned them but i flushed them and it has been 4 days the root growth has exploded the roots are about a foot to a foot and a half long but the leaves are still slowly turnig brown at the edges and curling up and down im growing in dwc tub with plenty of bubbles and no nutes right now 400w hps about 3 feet away water temp is about 71 f so i dont know what to do please help me also the ph is good

What are you temps like at the top of the plants?
Light might be to close and drying them out
quicker then they can replenish themselves.

I use my hand to judge and its warm at best i hanve a fan blowing on them the past 2 days so i'm pretty shure its not to hot

Also i noticed today its not just the tips of the leaves its around the edges and a few it started in the middle of the leaf

looks like sum type of nute diffecency

looks like it needs some nitrogen

Should i start giving them some mild nutes

i have gh micro,grow and bloom any suggestions dont want to burn them

dont use no bloom. you dont need it yet!
check the lables on ya nutes and start 1/4 strenth
and see how you get on.
also maybe back the light off a little and see if that helps.
although it doesnt burn your hand your plants are under it
for long periods of time. Just like if we sit in the sun long enough
we start to burn!
if ya water temp is 71f its probably going to be a good few degrees higher
at the top of ya plants.
get yourself a digital thermometer and then you can adjust your light height
to get optimum temps at the top of your plants.
or invest in a heat shield or cool tube. heat shield being the cheaper option
but they tend to diffuse the light slightly and reflect the heat away from the
plants. There ok but not great!
cool tube is the slighty more exspensive option and requires some setting up with
ventilation and stuff but works very well.