New leaf sets are coming out looking really sick! What to do?!

Hey guys, I'm a first time grower and these new leaf sets scared the hell out of me. They are also somewhat curling inwards... What am I doing wrong? How can I fix the problem?
Your help much appreciated,
Newbie Grower

looks to me like its either heat, over nute, or ph stress how are all of theses background info helps

Well it may be over nute. I have given my girls nutes only once, and this is the only one that had such a weird reaction. How do I solve the over nute problem then? How do I get to fix these poor leaves?

well the leaves are gunna stay that way you just need to focuses new growth and i wouldn't have add nutes just yet how old are they and what kind of soil most soil last anywhere from a few weeks to two months. to fix it, flush it go 3x the amount of water as you have soil. so one gal of soil 3 gals of water ok?

ok cheers mate! you helped a lot!!