I have a question. i have 2 H Gigas around 7 cm big living in separate enclosures. Can i start a communal set up with them at this size or must i just leave them be as is?

Hiya,
- just thought i'd add my three cents
I have also been trying to figure out how/ why pairings and communes work with some species and not others, would love to (responsibly) also set one up.
At the Emperors expo i met Milty who had the most awesome poecilotheria (indian ornamental x10) communal and was willing to share experiences:
cant forward an introduction but contact him: milty@mlltysacademy.com 073 1136 922 he makes up awesome enclosures also.
let me know what you discover (knowledge is power!) migsdecarvalho@gmail.com
- anyone with experience please add to this post?!

I would not put them together at that size.
Will probably end up with one fat gigas and some left over legs.
Best would be to try it with some slings from the same sac. Preferably as young as possible.

I must agree with Ceratogruys.
It will be be better if you get some slings and start from there.

Even with H. incei , when Adding larger adults together, some times it ends with loses.
It seems smaller slings are far more tolerable and less aggressive to each other.