I have experienced autos that do not flower on their own firsthand...they need to be flipped to 12/12 to force flower them and keep them there until finished. If you flip back to 18/6 you will throw them back into veg as they are not a stable auto.
Been a bit busy here lately and have slacked getting this going.
Here is what is currently in my tent:
2 Cream Caramel Auto Females
1 Purple Gem Auto Female
1 Papaya Photo Girl
All were germed on March 8. Here are the little cuties on March 14th:
I started out with 2 purple...
You are not going to see much difference between 18/6 and 20/4 except in your electric bill! As for 24/0 I believe every living thing needs a dark period for a bit of rest. I grow mine on 20/4...
Purple Gems
You should always have about 20% runoff when you water...that way you know she is getting a good soaking. When soil is dry to about the second knuckle she is ready for another drink. Jacks will definitely take care of Mg deficiency and I purchased it at my local nursery.
And thanks for the...
Your ph is fine for soil and she is definitely hungry as she is showing some Mg deficiency. Also when you water do you get any runoff? 1-2 cups every 2-3 days for her age doesn't seem like enough to give her a good long drink. IMO FF is overpriced and overrated... I am using Jacks Classic...
Even though I have a 400w cooltube, I have mine set up to draw air through the carbon scrubber and out of the grow area...no odor and temps are controlled....
Could be a Mg deficiency but hard to tell with no pics.... I started using Jacks Classic Dynamic Duo and have not had a problem since....
http://www.jacksclassic.com/dynamic_duo.html