Adds will constantly spawn while the boss is AoE'ing and debuffing the entire raid.
There are devices sitting on the Druid Ring that you can click to "release poison into the ground".
Have one person run back and forth, or two people one at each, constantly clicking these devices (there's a message that flashes across the screen when they are ready) and you won't get adds.
To deal with the AoE, have all ranged classes stay at max range, so only the MT (Main Tank) takes damage.
The final problem, and what still makes this hard, is that the boss will periodically dispel the entire raid. Your MT will lose HP buffs, defensive buffs, healing buffs, and hate buffs. Your raid will lose power-regen, and any other DPS buffs they give themselves or to the group. So, you have to hold back a bit so the tank can keep aggro, but at the same time your power-regen is constantly depleting.