3 week old CB Dutch Treat and Harlequin issue

[Habitants85]

Getting these ready for an outdoor grow. They are almost 3 weeks old. I've tried my best to keep my light a couple inches away from the plants. They seem really healthy but for some reason they are not filling out as much as I'd like and just growing vertically. Is this possibly due to the strain? They are cb dutch treat and harlequin. Should I be concerned about the height or even consider topping or too soon? Thanks.

 

[Carcass]

The distance from the lights is fine, but that light is just not strong enough.
There's enough light for the top of the plant, but not enough to support anything lower down on the plant- like more leaves & branches.
They are really healthy, but they just can't do any more than they're doing right now with that weak light.
Once you get them outside, they'll start growing like they should- how long before you put them outside?

 

[Habitants85]

The distance from the lights is fine, but that light is just not strong enough.
There's enough light for the top of the plant, but not enough to support anything lower down on the plant- like more leaves & branches.
They are really healthy, but they just can't do any more than they're doing right now with that weak light.
Once you get them outside, they'll start growing like they should- how long before you put them outside?

Another month before they go outside still cold up here.

 

[Carcass]

oof! ...Any way you can give them a little sidelight? like a couple of led or cfl bulbs..