curling leave tips??

hi all my plants are growing very well, just a bit concerned about the leave tips curling down and turning brown? Any suggestions?
Cheers

Are you sure you want us guessing?

The best thing to do when asking for help with your plants is including a clear picture or two of the problem. Since I have nothing to go by, I'm going to give you a link to bookmark for reference.

Good luck

http://greenmanspage.com/guides/plant_abuse.html

Here is another link to check.
http://www.ganjaguerrilla.net/index.htm

Its anyones best guess what is going on. Detailed info on your grow is needed to make a good diagnosis. You just did the equivelent of saying your car makes a funny noise, whats wrong?

maybe its the radiator?