Does anyone have a link for Healing Stream Totem scaling? I've been searching and don't understand some of the stuff I'm reading. Is there a good site explaining the mechanics?

I just noticed that with the mage in the group their is a proc adding about 70hp per tick per totem. Not sure what is doing that, but with the mage they're comparable to 2 resto + 1 elem.

I've never spent much time trying to max healing totems