boost vegetative growth rate in coco

So I am probably going SOG next grow. So far I was organic soil grower. I read basics few time so I will go canna a+b + calmag. I don't really care about bud boosters since I don't want a lot of weed (growing just for myself I got still few ounces left) so it is quality and variety of strains for me (that is why I go for SOG).

However I would like to boost my vegetative grow as much as I can. I will have 2 sativa so I want to boost Indica size as much as I can (and I can slow down sativa with topping and LST) to achieve biggest plant possible in that 3-4 weeks of vegetative grow since with Kali mist and Arjan's Haze #3 on board I won't be able to give them more.

Any idea which nutes can help me with boosting vegetative grow of my non-sativa plants?

Is Rhizotonic any good for that purpose?

A good root system ...root stimulater in veg is what boosts growth..and grow in coco..canna coco pro...theres nutrients added aswell...biger the roots bigger the fruits...