The Grox has 2400 planets, so it can take 4 weeks to defeat them. How long does it take to destroy the GROX?
HOWEVER, if you declare war on the Grox, there is no way to stop it unless you destroy them. If you ally with the Grox, all or nearly all species in the galaxy will declare war on the player controlled empire. Grox are much more powerful than other empires. Remember, you can pay allies to attack the Grox and they won’t destroy colonies. If you want to play the part of the good guy, fight them. If you want total galactic conquest, ally with the grox.
