Does anything effect the damage of Scalding Water on the lurker below fight? as of right now my guild is doing lurker and everyone in the raid takes 450-550 damage from the water and I only take 250, I was wondering the reason behind this.

Sorry if there was already a thread about this

Do you have blessed life?

Blessed Life would explain it. When you jump into the water, you get a dot applied which means that it is possible that it is checked on the application of the dot. This would also explain why rogues are able to clos off sclading water, as it is only applied when they jump in initially.

Did you notice these 250 ticks happening sporadically, or all the time when you jumped in the water?

You deal the damage to yourself, from scalding water. As far as I can tell, the water effect rolls for Blessed Life when you first activate the water, not even when you jump in; someone else got that 250 tick, and it persisted at 250/tick every time he jumped in, even after he died and was rezzed.

It does re-check some things each time you jump in, though. Crusade means means the water at base always hits me for 515 ticks, and sanctity aura makes that 525. I still get hit for 525 when I turn the aura off, though, until I jump at the surface of the water long enough for the debuff to fade for a second, then it drops back to 515.

Yes I do. I think thats what was affecting it but when i died and went back into the water it was doing 500. So i am not sure why it bugged out

Your combat log registers scalding water like this:

Your Scalding Water hits you for 500.

This means that all talents, buffs and effects that over a % amount of damage reduction/increase will effect Scalding Water.
It even goes further, as for example for warriors with Improved Defensive Stance, they will get a reduction twice. Once for dealing the damage, once for receiving it.

Other effects that increase/decrease: Humanoid Slaying, Elemental Warding, Blessed Life, ... and so on.