Quarantined Tank for Gigantea

[Deepsea2005]

Hello all,

Can you help me out?
Currently, I have a Purple Gig in the main tank, and I'm planning to have a Blue Gig soon.
How can I build the best quarantined tank for it?
I have a spare 30 gallons tank, can it big enough?
Should I build a whole system for it; with life rock...., or?
How long should I keep the Gig in the quarantined tank?
I kind of glueless in this area, can you all kindly help me out?

Thanks,