Good question dude so i have given it some thought, I don't think its the strain, 2x Big Easy's again to do a comparison with the first 3 and 1 x AK49. I did change few factors, so it go's on record (and i don't forget) I though i would list everything i did different.
- different pots, same volume 25ltr but not my home made air pots. They are the usual square pots you see used a lot
- tier planted all 3
- Different nutes, Plant magic old timer range plus they have had Bio-silicon from the start.
- Used Over Grow foliar spray for 2 wks just before and during stretch
- Different soil mix, a layer of coco on the bottom to act as sponge then 1/3 coco, 1/3 Bio bizz and 1/3 B&Q verve compost mix
- practically left them alone for the first 3wks, did not feed until end of wk3.
- started to train a bit later
- pony tailed 2 and fimmed one
- mini scrog on 2 and one el-natural
- had the light much high at the start, over 30"
... sorry 
