help first time

i have got 5 clones they have been growing for nearly 2 weeks the some of the leaves are starting to curl down and the stems have turned purpleish i have been told it could be nutrient burn or heat stress but i havent started to add any nutrients yet i have just benn using normal water at a ph of 6.2 so i raised the lights a bit they look a bit better but the lower leaves dont look very healthy i also have a problem with humidity keeps dropping to 30 but i keep putting a bucket of hot water in my drow tent to raise it does anyone know if it sounds like i have done something wrong and any advice what to do

dosen't sound as it much is wrng - keep the lights not too close - pics you'll need too
how are the roots?
if they're not rooting properly it could be the problem..

When you got the clones did you put them into soil or rock wool ? Did you use a rooting hormone ?

i got the clones of someone when i got them they was already in rockwool i think the person had already used a rooting hormone on it i could see it round the stems i waited til quite a few roots was sticking out the bottom and sides of the rockwool then transplanted into a pot with canna coco growing medium in it i was also misting the plants with water while the lights were on but i have stopped now because i read somewhere its not good for the plant. the lights are off at the moment i will take some pics when the lights are back on