It's not a hard fight, but everyone needs to stay focused the whole time. We wiped 5 times at 1% only because we had deads on last phase... people taking double lightning, not running fast enough to take a hit...

Best advice I could give: your SMN and maybe your WHM will have to learn MP management (that wille come with experience of the fight anyway). As a Bard, singing too soon Ballad or even Pean is stressing.
Practice Phase 2. The mechanics in that phase will be the used in last phase, only in a (lot) smaller area. If you master this "combo" then you pretty much master the fight.

And the usual like everyone said already: food, X-pots of stats, poison pots, and BfB to be used wisely.
We used the hard way: no poison pots, only one DPS with ilvl 115 weapon, one melee, and Bard in melee range instead of SMN. But it worked anyway.