curled down leave tips?

Does anyone know what causes the tips of the leaves to curl down, and some yellowing and dying leaves. the yellowing and dying leaves are here and there not everywhere. these plants in the pics are around 30 days flowering under cfl only. these are Yellerz gurlz and she waters them every 3-4 days or when the pots get light to the lift. i kinda think shes underwatering but i am a newbie!

Anyone? were going to take some new pics today.I'll have them up shortly.Any help would be great.

The yellowing may be from a shortage of nutrients. . .try getting plant food from a nursery and add some with every 3rd time you water them or so. . .it may also be from not getting enough light. . .hope u come right

heres some pics from today.theres some weird spots on some of the leaves near the top of one plant.and alot of curled down leaf tips.

Trichopathic1 said:

heres some pics from today.theres some weird spots on some of the leaves near the top of one plant.and alot of curled down leaf tips.

Click to expand...

I have had a similar problem. WIsh I could help.

my plants are the same 3 weeks flowering, after having a good read around, i am assuming it is too much N, i have since flushed them with ph'd water and they seem to be picking up, all the newer leaves are ok. just a suggestion.

you really have nothing to worry about, check the soil for ho wmuch water it has, if its pretty dry, add water,but those are gorgeous, you have no worries yet