why didnt my plants double in size?

i recently grew 3 m39 clones and when they flowered they ggrew 7-10 inches and the yeild was horrible , could it be because of using a smalll pot 8 inches <-> ???

out of subject sorry , but would you by any chance be around Montreal ?

Most M39 comes from there ....

yes very much so it is probably from using small pots. is that 8 inches square?

The better the root system, the more energy the plant can produce toward growth. For a large (indoor) plant, you will want either 3 or 5 gallon pots.

how long did you veg them before you flipped the switch to 12/12?

veged for 4-5 weeks and flowered for a week or 2 and then trans planted to random pots but they were 3 to 4 times biggger then the ones they were in the.

could just be a low-yeilding plant

m39 is supposed to be very hihgh yeilding

What kind of lighting you got?

Well.....Number 1...You really want to give your plant as little stress as possible during the flowering cycle....transplanting should have been done during Veg..Pics would say a thousand words though...is your plant tall and skinny(stretched) or short and bushy....Usually transplanting is done a LOT earlier than flowering...by that time the plant should be in it's final home pot..Secondly, how far was your light...any nutes??? Did you top/LST/Supercrop...alot of factors come into play. But transplanting probably is the answer...If you have inadequate lighting, it could cause a low yeld...Sometimes when a plant is promoted as a "High Yielder" it is often the creator saying..."If you are an advanced or Novice grower, you'll get a high yield" C99 is a high yielder, but if I dont LST or top it, the buds that recieve less light will not be that greatly sized...post some pics dude!!! Im sure someone has expertise with M39.....GOOD LUCK BRO!!

ty man that was insppirational, i would upload pics https://www.rollitup.org/general-marijuana-growing/373088-m-39-week-5-flowering.html thats my planst right there ty brathaffeed me the feedback man