Hello RIU!! Help needed

Hi all,Need some help with my grow

i think i have been jumping the gun with my grow and not waiting for things to develop properly

i am growing in Coco

100x100x180 tent

400w MH for veg

400w hps for bloom

prima kilma 2 speed RVK fan 220/330 m3

canna nutes full range.

The ladys im growing are DP blueberry,DP power plant,and jack herea.

all has been growing great so far.... they are 19 days old from seed and the BB is almost 12" wide!!! and the plants are in there adult pots and ready to go(have been in them since day 5) roots are well developed and i can see water roots poking thru the holes in the bottom of the pots

so this is my problem....been using the MH all this time at 18/6 quite close to the ladys around 12" away the plants are loving the light and even the very first leaf sets are wide all the plants are still quite short about 4-5" tall and have a been topped at the second internode(they look like giant seedlings kind of LOL)
So i have been working from a canna coco feeding sheet and light shedule and have been following it to the T,the sheet says to give 18/6 lighting for week one +/- (i have given them 18 days worth)
then the sheet says the give 12/12 lighting for 3-4 weeks for vegative growth.....,so i changed them over to 12/12 yesterday should i have left them in 18/6 longer? i have a feeling i should have i understand that when you switch to 12/12 that veg continues for 3-4 weeks anyway before bud production begins....this was my reasoning and why i flipped the lights!!???

Have i f**ked them up?(they still look pukka and are praising the lamp)

Can i revert back to 18/6 with out f**king them up???

what would you guys do? the tent is quite tall but i really only want 3-4 ft plants

help me out please rasta's

Peace
Red

Either switch them back ASAP or keep them at 12/12 with the HPS light and start bloom nutes next weekend.
If your trying to keep them short, leave it at 12/12

Boneman said:

Either switch them back ASAP or keep them at 12/12 with the HPS light and start bloom nutes next weekend.
If your trying to keep them short, leave it at 12/12

Click to expand...

Cheers boneman!! what would you say "short" is in you opinion??
and do i change the MH for the hps to make the plants start to reach for the light.

if i go back to 18/6 will i have a risk of herming the ladys into ladyboys

cheers boneman!!

Boneman said:

Either switch them back ASAP or keep them at 12/12 with the HPS light and start bloom nutes next weekend.
If your trying to keep them short, leave it at 12/12

Click to expand...

Ok have put them back to 18 6 ,hoping the full day of 12 12 has not fooked em