Make sure to clear your stacks before each Total Annihilation. This is imperative. Your healers will oom way to quickly otherwise. If you have any self-healing or shields then use them for this.
Zalid I have switched to Temporal Shield so when Total Annihilation hit me for 300K I got it all back at 100K every 2 seconds. Timing is quite key though. It's on a 1 min cooldown so in theory I can soak each one.