Help Please: New leaf growth suddenly went skinny, tiny???

Hi RIU!

As part of the grow schedule I just fed my girls 3 days ago, (Nova Grow - Veg).
PH of nute solution was 5.8.
Soiless grow, using Pro-Mix.
600 W HPS.
18-6 Lighting.

All of a sudden it seems that all the new tip growth (upper near the light and lower sites) have changed to look like this.... (the HPS lights are washing out the color a bit...)





I am trying to ID the def using the RIU plant abuse thread, it would seem to be a Zinc def.....??

You can see in the background of the pics that leaf growth was coming along nicely... till this issue started.

The grow tips are now bunched up with very, very skinny leaves and some leaves are exhibiting a twisty appearance???

Does this look like a Zinc Def?

Any assistance and direction would be most appreciated....

Thanks in advance

Kayuman

bump! This is happening to me too. Can anyone help??

here ya go fellas.
http://www.icmag.com/ic/showthread.php?t=11688

ph is way low for soil.6.5 is good.
that same thing happened to me but my $85 ph pen was reading wrong so it through my ph way off.

just looked at the post date.old post sorry