Trying to identify cause of yellow tips on leaf (Age: 1 week)

This is my first time growing and everything seems to be going smooth, however these 2 bubblegum hybrids are only 1 week old and I've already noticed a yellowing at the tips of the leaves. I started out with rapid rooters and transplanted these into FF's Ocean Forest soil, without using any nutes yet. Does this look like a problem with acidic water? Or maybe the plant is too small to be under my 125w 6500K CFL and heat is the cause of the problem? I know it doesn't look like much, but I'd like to take care of it now before it becomes a problem. Any help is appreciated, thanks.


Notice the yellow on the tip of the bottom left leaf (closer view):


Here's the other one:

I guess the yellow cotyledons on that one plant are normal, but notice the tip of the leaf (closer view):

Without getting into all my bs and problems i would suspect pH ....but i'd wait for someone with solid soil experience to chime in.....i''m interested too.

Thanks for the reply. pH is the only thing I haven't been monitoring, though I have tap water sit overnight so the chlorine evaporates, but I guess that doesn't do much for pH. I'll have to grab some strips.

Im going to go with nute burn???? Although you say you dont asdd ferts i've always heard FFOF soil is naturally "hot" so you could be burning it still. Im trying my first soil grow so dont take me too seriously.

no worries I've read some reports about FF Ocean Forest being too nute rich for seeds (possibly seedlings too?), so as far as I know it's possible. I actually wasted 5 mazar seeds trying to germinate in that soil (contributed with a heat mat), so I went the rapid rooter route which worked wonders.

I use FFOF for every plant I have...lol. Hell! I even clone straight into it...as long as you water correctly there is no burn...those leaves are supposed to fall off...you can't possibly give a plant too much light with some CFLs...my seeds break soil to a 400w MH and they have no issues...grow like crazy in fact. I would water less...for sure...and just wait...even if the soil is a little hot it won't be for long...just let it dry a little.

Thanks missnu, I wasn't sure if I could use that as an early indicator for a deficiency, but from what I've seen these are resilient little bastards. I water maybe every 24-48 hours, and give it an occasional spray when the rapid rooters in the soil get too dry. I'll try to make them more thirsty. I figure my 1ft CFL would've killed them by now if it was too hot, but they seem to be loving it.

It seems heat was the issue, as I woke up today one of the leafs on the bigger plant started to curl inwards i just modified my grow box so it has an intake and exhaust fan with a small internal fan. hopefully this does the trick.