flowering problems / help advise urgently required

done a few grows with no issues but as its a loft grow ive experienced a bit of problems with my recent grow !

my recent grow vedged perfectly but im not hitting week 5 of 12/12 flowering and the buds have just began to show last week
due to low temps hitting about 6 / 8 oc i had a fair amount of stretch on plants but slow bud formation , i was also using a cool tube so temps were not hitting over 18oc either.

i have now fixed temp issues and have a max 29 oc and min 18oc.

i have 2 questions i need help with please

1. will this flower period of plant be finished at week 8/9 or should i count from last week ?

2. due to stretch of plants i cant put another light on top without burning tops of plants so is it possible to put a light on bottom of tent facing up as i have plenty room for this.

plants are critical kush in dwc, all look very healthy apart from big stretches inbetween . just need to know if its better to cut my losses and start again ?

thanks

Photos would be helpful.

You should count flowering from the time the plant shows its first pistils, not the day you switched to 12/12 lighting.

Stretching could occur for a few reasons:

-genetics
-light spectrum (blue lights reduce the stretch)
-light being too far
-inducing flowering (switching to 12/12)
-Small pots with no more space for root growth

Putting a lamp under is ineffective, as only the green top of the leaves can properly absorb light.

cheers was hoping that as pistols just started to show over a week ago. the light in bottom helps with daytime temps but i was hoping it would bounce of the foil sides of tent and help with more budding so if totally inefective i may just keep my bar heater on 24/7 instead . im pretty sure the extreme stretching was down to low temps but its stopped growing now anyway issue was they are touching top of tent and ive got the cool tube in middle between the 4 plants and removed burnt tops.

ill try get pics up tomorro they are in 20l dwc buckets , critical kush im trying this time, done cheese nl blue and blz bud before with no probs

all help appreciated as i was considering chopping this and binning as it took about 4 weeks 12/12 for first pistols to show

sandmonkey said:

Photos would be helpful.

You should count flowering from the time the plant shows its first pistils, not the day you switched to 12/12 lighting.

Stretching could occur for a few reasons:

-genetics
-light spectrum (blue lights reduce the stretch)
-light being too far
-inducing flowering (switching to 12/12)
-Small pots with no more space for root growth

Putting a lamp under is ineffective, as only the green top of the leaves can properly absorb light.

Click to expand...

The time it takes to start flowering depends on how mature the plant was (veg time), and this changes from one strain to another.

How high is your grow room and how long did you veg for?

What you could get is something like a fan heater. I have an oscillating one that I can adjust the temperature with.

vedged for about 6 weeks after seeds fully rooted they grew perfect just loads of stretch in them, thought criticalkush was small and stocky so didnt expect as much stretch , tent is only 180cm high, vedged them to about 60 / 70cm high..

budding started to form quite quick last few days, prob gonna leave light in bottom as its giving goods temps and i have a fan blowing round at top and an air intake at bottom plus extraction fan. fan heaters are 1kw to 2 kw so a 400w lamp is bottom is prob better for energy usage..

looking a little better last few days and they are now consuming a good bit more feed and water, just hoping the budding will now continue to grow and it didnt start weeks ago as today would have been week 5 of flower normally in my grow..

sandmonkey said:

The time it takes to start flowering depends on how mature the plant was (veg time), and this changes from one strain to another.

How high is your grow room and how long did you veg for?

What you could get is something like a fan heater. I have an oscillating one that I can adjust the temperature with.

Click to expand...

Don't feed the critical kush to much, they don't like it but can still handle about 65% of full strength. Now that they've started to form watch for them to explode! My critical kush is almost at week 8 and will probably go another two weeks but they are massive buds and frosty as hell! Hope you have a good filter though cause they stink like crazy. You made a great choice going with the critical kush; definitely my favourite in the garden!
would love to see pics of your girls!
oh and yes they do stretch a fair bit too but they produce huge buds so that space between nodes will fill right up
up
what light are you using?

got a 600 cool tube at top and the 400 at bottom is mainly to maintain temps, 4 plants from seed in dwc.. did you have any probs like myself ? after 5 weeks in 12/12 only recently has the buds come as above mentioned altho im more confident as i see more and more formation every day had blz bud before this and surely they cant stink anymore than them altho just upgraded to a rhino filter so hoping this works better but this was reason i changed from blz it was just too much prepared tho if filter doesnt kill smell ive got una blocks and an ozone plug for outside tent just incase .. try get a pic up over next few days