Ideas about yellow tips on new growth??

[First Time Caller]

What a difference a day makes Yesterday I posted a thread on indoor growing about stretch or lack thereof:
http://www.marijuanapassion.com/forum/showthread.php?t=48357

Mid-day today, I looked in on the grow box to find a couple of the tips on the new top growth yellow. None of the new growth on any other part of the white widows, show this yellowing. My initial thought is this is heat related from having the lights too close, as in the tops in the middle of the splitter for two cfls. I've back the cfl's off to 2"(5cm).

Plants are white widows, 2.5 wks since breaking ground, temps are mid seventies measured at plant middle, PH is 6.8, soils is foxfarm 5:1 ocean forest/light warrior, no nutes just distilled water from day 1.

I can make a trip to the grow shop tomorrow if thoughts are it is anything other than too close to the lights. I'm thinking about picking up some Grow Big for the other 3 Indicas anyway.

Hoping it's just light related but ..... thoughts??

 

[purplephazes]

I Realise these are WW Nute sensitive ! But i think 1/4 strength feeding will help it... may be phospherous or mag defiecency ! A light feed should prevent this from getting worse ! This is only recommended as long as you are sure that your ph is 6.8 and your ph meter is calibrated correctly ! Peace and all the best !

 

[poop-dog]

Over watering, PH being to high, and nute burn have all done that to me. Looking good though!

 

[First Time Caller]

I Realise these are WW Nute sensitive ! But i think 1/4 strength feeding will help it... may be phospherous or mag defiecency ! A light feed should prevent this from getting worse ! This is only recommended as long as you are sure that your ph is 6.8 and your ph meter is calibrated correctly ! Peace and all the best !

Thanks, I just checked all the ph's and got 6.8/6.9 on all the plants. I would like to see that a little lower. I'm going to bring my meter with me to the grow shop today and check it against a known ph just to make sure it's accurate. Fingers crossed as it doesn't seem to be any worse this morning.

Over watering, PH being to high, and nute burn have all done that to me. Looking good though!

When I brought one of the white widows upstairs last evening to get the wife's (experienced greenhouse grower) opinion on the need for watering...I may have fallen prey to the typical first time grower mistake. She felt the top of the soil and immediately said, "nope, wait at least another day, maybe two" I just checked the new jugs of distilled water I have and found them to be 7.0. I'm thinking a little ph down, as I'd like to get the medium down to 6.7/6.8 or so...thoughts?

As was said on the old TV show.................I have to learn, "patience grasshopper"

 

[Parcero]

Some of my NL's are showing same kind of yellowing tips, occaisionally and then as more new growth comes the yellowing tips just disappear without me doing anything. Maybe lights, but cant be sure because some times the tips yellow on plants that are further from lamps than the ones just underneath.
I like the disappearing part.
Hope you tips turn green later on aswell.

Good luck

 

[First Time Caller]

Some of my NL's are showing same kind of yellowing tips, occaisionally and then as more new growth comes the yellowing tips just disappear without me doing anything. Maybe lights, but cant be sure because some times the tips yellow on plants that are further from lamps than the ones just underneath.
I like the disappearing part.
Hope you tips turn green later on aswell.

Good luck

Thanks, I just got back from the grow shop where I had my ph meter checked and bought some pH down. My meter is dead on. I just checked various places in the medium and still find the ph to be 6.8/6.9. I just added a little down to my water and will water with a ph of 6.6 and see what happens.

Thanks again.