The only way the fight is hard to heal is if people stand in the fire like idiots. People need to be moving once they see the cast timer. Even if it's not pointed at you, it's better to be reactive and move than stand there and not notice it was you.
I have it setup where it is very obvious who has a magic debuff on them. When I cleanse it, it goes away completely. It's not something you have to spam dispel. :S
It may seem like it's not working to you because they get reapplied pretty quickly, but it's still worth it.
On break / retired from WoW until WoD(?)
Currently playing Wildstar as a Stalker. Rawr. :3
that fight is all about "not standing on fire". tell tank to do so. dispelling 20 stacks is not an option. that fight can be very easy and very hard. all depends on where players stand.
when the boss is casting... dispell the tank.... during fire bombs... dispell the tank.
use holy word serenity on cd and keep renew rolling... you also have pw shield if tank gets low.
i usually fiend and hymn of hope during first fire bomb, second one i use divine hymn..... always after dispelling the tank of stacks.
make sure dps know to kill one hatcher at first then focus only on dragon adds till they're all hatched then focus on boss.
boss hatches all eggs at a certain %... so make sure all eggs are already hatched
Now if you don't have an issue removing pointless damage, that's fine, continue your way, however the OP is having issues healing this and as others have mentioned, dispelling the stacks lowers tank damage (assuming he's not a bad and has aggro on the dragonhawks) considerably.
To OP: Check recount or skada, whichever you use (if you do) and look at damage taken, if you're finding the tank unhealable then he is likely standing in either the fire line, a bomb or the DPS aren't killing the dragonhawks. As mentioned cleanse the stacks every 5-10 stacks or so, you'll notice a difference. Pop cooldowns when he hits 35% and the flood of dragonhawks comes out, that's when most of the damage output is done, also it helps to stand near the tank if you can avoid the fire lines as this will bring the dragonhawks to him, making them easier to pick up. I've had quite a few tanks turn their backs to the boss to pick up dragonhawks which leads to more unnecessary damage.
I tried not dispelling once, they went straight through GA, tank cd's and spam flashx2+gh due to tank being on 120+ stacks. Yes, the dps was horribad. Yes, I was horribad for not dispelling there too.
I had an argument with a guildie a long while ago about the dispelling. They thought it removed only 1 stack.
My frames will show me the number of stacks and time remaining on the debuff. When I hit dispel when the tank has 40 stacks, it will remove ONE stack to 39 stacks. Then ALL of them drop off. There's a delay on the drop of about 1s and it's not because they were about to drop off anyway. I realize it's counter-intuitive, but it's what happens and has been that way as long as I can remember.
A lot of people are stating, "If the tank's not an idiot, then he will ...." and "If the dps isn't horribad, then ...."
The fact of the matter is, in a pug for LFG, oftentimes it's left up to the healer to heal through stupid and lazy. In that case: Dispel the stacks when it's worth it, be ready to fade when a massive group of birdies spawn, avoid fire, and be ready to GS a dps if the tank is slow on the pickup. It really shouldn't be that hard
Only fights in ZG/ZA where damage is unavoidable and spread are Kilnara and Akil'zon. Also the only two fights you can claim should always be healed in sanc.
I went back there today to test it out... and yes cleansing does remove all stacks, but it might take a moment to wear off.
I'm pretty sure it has not always been like this, but cannot say 100%. Anyways you learn something all the time. :-)
use default raid/party frames - then you'll see it removes all stacks with 1 dispell. I've seen 40 stacks disappearing from me at once - so ye if you see that only 1 stack is removed - fix your addons..
Don't spam flash unless it's REALLY necessary or you'll be oom super fast. Serenity is the best chakra to use due to the instant heal and +crit it puts on your target. Don't use sanctuary, if the dps are standing in shit that's their problem and they shouldn't be - they should be healable with minimal use of prayer of healing, p.o. mending, CoH and renews when you have some spare time. Make sure you're using prayer of mending on each cd and rolling a renew on the tank; if they're standing in the fire, grip them out of it and maybe they'll get the idea. If the DPS ends up tanking the adds, then you'll probably need to GS and spam them for a few seconds, but with any half decent dps they should die quite fast.
Oh, and dispel if stacks get over 10.
If you're lacking any power behind your heals, maybe give un an armory link so we can provide some advice?