FoL costs 1186 mana to cast. And assuming haste brings the cast time down by a bit, spamming this will have you cast this 4 times every 5-6 seconds, meaning it uses 4744 every 5 second period approximately. My combat regen buffed but not including mana from judging or CDs, is 642 every 5 seconds, meaning using this method of healing, I'd be spending about 4100 mana every 5 seconds. (rounded.) At a mana pool of about 34K, (i know... i know... I'm working on it...) I should be going oom without judging or mana CDs in about 41 seconds.
now of course, I judge, and I use mana CDs, so this time is a bit longer, but I still end up going oom at the end of the fight if I want to keep my heals up.
Anyway, I've been told that with more int it shouldn't be a problem, but I don't see how. Assuming someone with 40K mana has about the same regen, (I asked the holy pally that was helping me, he has about the same. Right now part of the difference in mana pools is from lack of gems/chants, and the fact that some of my stuff is still mail, so I'm missing out on the 5% int, but that doesn't affect regen) that would only give then another 2 and a half cycles of using this before going oom as well. What's stumping me is that my holy pally friend isn't going oom as much as I am even though we're doing the same thing.
Now in a non guild run, I was healing on LK for some 10 man for a friend. I found it far more efficient to use something like this:
HS> HL if I get an infusion proc/ FoL if I don't> HS with daybreak from HL, so that I can do a second if the 1st doesn't get an infusion proc> repeating with WoG in when its at 3 HP.
My reasoning is that with infusion of light, HL casts just as fast as FoL, but, I regen 3 times the amount it costs to cast every 5 seconds, meaning its a relatively even exchange of mana spent vs mana regened, especially taking into account judgment, and I'm still keeping the tank very much alive.
anyway, just wanted some help with this. My friend tells me its all better with a bigger mana pool, but like I stated before, it doesn't seem like this would help for more than 12 and a half seconds more.