Curling Leaves too much or not enuff water?

[doggboy]

Hey hey,
new bunch of clones just gone in and i have changed my watering system somewhat, and am now using pearlite and clay with watering happening for 15 mins on every 3 hours, now the clones seem to be going great however the leaves have started curling up at the outside, is this too much or not enuff water or is it perhaps a nutrient defficiency, can anyone paleeeease help,
thanks heaps in advance

 

[Tokensmoke10]

Curling leaves can be from too much AND too little water

Here's a link with the most common problems that might come up during your grow.
Cannabis Plant and Pest Problem Solver - Pictorial

 

[Baja Big Dog]

UI watered my babies, (up to about 3 weeks) twice a day for 15 minutes, they turned out great, I then went to 6 times at 10 minutes, and now in flower (4 weeks) im at 6 times for 15 minutes...